Anita A. Harteveld¹, Nikki Dieleman¹, Laurens J. De Cocker¹, Catharina J.M. Frijns², Fredy Visser^1,3, Peter R. Luijten¹, Jeroen Hendrikse¹, and Anja G. van der Kolk^1
1Radiology, University Medical Center Utrecht, Utrecht, Netherlands, ²Neurology, University Medical Center Utrecht, Utrecht, Netherlands, ³Philips Healthcare, Best, Netherlands

Intracranial perforating arteries are crucial for the perfusion of the deep gray matter structures of the brain. Due to the size of these small arteries a high spatial resolution is necessary for clear visualization of these vessels. Therefore, in this study we evaluated high resolution 7T post-contrast TOF MRA in patients with cerebrovascular disease. We demonstrated that six intracranial small (perforating) arteries can be visualized. The intracranial feeders of the anterior spinal artery were visualized for the first time. The presented sequence may have additional diagnostic value in the clinical evaluation of patients suspected of pathology of the small (perforating) arteries.

Jeffrey H. Maki¹, Charles S. Springer, Jr.², Mark Woods^2,3, Sarah Bastawrous^1,4, Puneet Bhargava^1,4, Miles A. Kirchin⁵, and Gregory J. Wilson^1
1Radiology, University of Washington, Seattle, WA, United States, ²Advanced Imaging Research Center, Oregon Health and Science University, Portland, OR, United States, ³Chemistry, Portland State University, Portland, OR, United States,⁴Radiology, Puget Sound VAHCS, Seattle, WA, United States, ⁵Medical Affairs, Bracco Diagnostics, Milan, Italy

Dynamic contrast-enhanced MRA (CE-MRA) makes use of Gd-based contrast agents (GBCA) during first pass. Optimizing CE-MRA requires, among other things, an understanding of GBCA relaxation (R1 and R2*) properties in whole blood. We examined relaxation of four GBCA’s in whole blood under physiologic conditions. R1 relaxivity is very non-linear; secondary to both RBC finite water exchange kinetics and (for protein-binding agents) albumin binding. Furthermore, R2* in whole blood is much greater than in plasma. Both of these effects combine to give less signal than might be expected for the CE-MRA sequence, particularly with higher injection rates. This will be explored.

Mahdi S. Rahimi¹, Kang Wang², Lauren A. Keith³, James H. Holmes², Jean H. Brittain², Harald J. Kramer⁴, Scott B. Reeder^3,4, and Frank R. Korosec^3,4
1Biomedical Engineering, University of Wisconsin Madison, Madison, WI, United States, ²Global Applied Science Lab, GE Healthcare, Madison, WI, United States, ³Medical Physics, University of Wisconsin Madison, Madison, WI, United States,⁴Radiology, University of Wisconsin Madison, Madison, WI, United States

Peripheral vascular disease is one of the leading causes of disabilities in the United States. Despite recent advances in contrast enhanced MR angiography, new techniques for better diagnosis and monitoring of the disease are of interest. Patients with PVD were scanned using an undersampled Interleaved Variable Density (IVD) sampling pattern and a constrained reconstruction algorithm (HYCR), and images were compared with X-Ray Digital Subtraction Angiography (DSA). Optimized IVD-HYCR technique shows higher spatial and temporal resolutions and superior temporal behavior compared to existing clinical view-sharing methods and the images agree well with DSA.

Kang Wang¹, Scott K. Nagle^2,3, Scott B. Reeder^2,3, Philip J. Beatty⁴, Mahdi S. Rahimi³, Laura C. Bell³, Jean H. Brittain⁵, Frank R. Korosec^2,3, and James H. Holmes^1
1Global Applied Science Laboratory, GE Healthcare, Madison, WI, United States, ²Radiology, University of Wisconsin-Madison, Madison, WI, United States, ³Medical Physics, University of Wisconsin-Madison, Madison, WI, United States,⁴Sunnybrook Research Institute, Toronto, ON, Canada, ⁵GE Healthcare, Madison, WI, United States

Channel-by-channel (CBC) data-driven parallel imaging may suffer from long computation times for multi-phase dynamic imaging, which can limit its utility in a clinical setting. This is particularly problematic with high channel counts, large parallel imaging factors and large matrix sizes. This work demonstrates the feasibility of a recently developed Direct Virtual Coil (DVC) technique to reduce the computation time for parallel imaging in dynamic imaging applications.

Ghaneh Fananapazir¹, Daniele Marin¹, Paul V. Suhocki¹, Charles Y. Kim¹, and Mustafa R. Bashir^1
1Radiology, Duke University Medical Center, Durham, NC, United States

Ferumoxytol is a supraparamagnetic iron oxide agent that has been used as an off-label blood pool MR contrast agent in patients with end-stage renal disease (ESRD). Twenty-six MRIs performed in patients with ESRD who underwent abdominal MRI with ferumoxytol were evaluated. Several significant vascular findings were observed, including thrombosis, dissection, and aneurysm. However, artifacts that mimicked vascular thrombosis were present in more than half of the patients. The prevalence of the artifact appears to be related to the concentration of delivered ferumoxytol, possibly owing to susceptibility artifact from increased T2* effects.

Pan-ki Kim¹, Bong-sik Jeon², Eun-Ah Park³, Eung-Gyu Kim², Wan-Jae Myeong², and Whal Lee^3
1Seoul National University, Seoul, Korea, ²Hanwha Chemical, Daejeon, Korea, ³Seoul National University Hospital, Seoul, Korea

Recently developed extremely small-sized iron oxide nanoparticles (ESION) contrast agent was made of 3 nm-sized nanoparticles. So that can be utilized as T1 contrast agent like a gadolinium based contrast material due to have a character of high r1, low r2/r1 ratio and long blood half-life, as previous study. This study was carried out to evaluate whether ESION is clinically useful through the rabbit thigh vessels MR angiography that acquired first-pass and equilibrium 3D MR angiography with high spatial resolution to compare with conventional Gd-CE MR angiography and a reference standard digital subtraction angiography (DSA).

Lynne McCormick¹, Jonathan Weir-McCall², Richard White², Stephen J. Gandy³, Jill Belch⁴, and John Houston^2
1The Institute of Cardiovascular Research, University of Dundee, Dundee, Angus, United Kingdom, ²Clinical Radiology, Ninewells Hospital and Medical School, Dundee, Angus, United Kingdom, ³Medical Physics, Ninewells Hospital and Medical School, Dundee, Angus, United Kingdom, ⁴Division of Cardiovascular and Diabetes Medicine, University of Dundee, Dundee, Scotland, United Kingdom

Contrast-enhanced whole-body MRA enables cardiovascular analysis of the entire arterial tree excluding the coronary vessels, enabling characterization of atherosclerotic disease on a systemic level. As part of on-going work in whole-body MRA analysis, this study examines reproducibility and variability in radiological stenosis quantification between two cardiovascular radiologists, and therefore the extent of observer influence on cardiovascular assessment of images in both single site and whole-body atherosclerosis scoring. Analysis was performed at 159 arterial locations for each of 20 patients, including screening and clinically symptomatic patient groups.

Tao Zhao¹, Shihua Zhao¹, Minjie Lu², Xiuyu Chen², Gang Yin², and Qiong Liu^1
1Radiology, Fuwai Hospital,Chinese Academy of Medical Sciences (CAMS) and Peking Union Medical College (PUMC), Beijing, Beijing, China, ²Radiology, Fuwai Hospital, Chinese Academy of Medical Sciences (CAMS) and Peking Union Medical College (PUMC), Beijing, Beijing, China

To evaluate the correlation between the ventricular arrhythmias, including frequent premature ventricular arrhythmia (PVC), doublets and non-sustained ventricular tachycardia (NSVT) on 24h Holter electrocardiogram (ECG) in HCM, and the late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR). Patients with LGE had a nearly 6-fold higher risk of NSVT than those LGE negative patients. The correlation coefficient between the fatal ventricular arrhythmia and the LGE score was 0.680. In multivariate analysis, LA anteroposterior diameter and LGE score were the independent determinants of NSVT. Ventricular arrhythmias are closely correlated with the LGE of CMR, and its prevalence is increased with the increase of LGE extent.

Britta Butzbach¹, Andrea Protti², Xuebin Dong², Frank Tacke³, Matthias Bartneck³, David Onthank⁴, Eike Nagel¹, Ajay Shah⁵, and Rene M. Botnar^1
1Imaging Sciences, Rayne's Institute, London, Middlesex, United Kingdom, ²Cardiovascular division, Cardiology, London, Middlesex, United Kingdom, ³Medical clinic III, Gastroenterology, Aachen, Nordrhein Westfalen, Germany, ⁴Discovery Biology and Veterinary Sciences at Lantheus Medical Imaging, Boston, North Billerica, United States, ⁵Cardiovascular Division, Cardiology, London, Middlesex, United Kingdom

Assessment of post infarct remodelling in CCR2 and wild type mice was conducted with an elastin-binding contrast agent. MRI was compared with histology and shows that imaging of post infarct remodelling is feasible with an elastin-binding contrast agent. 7 days after permanent ligation there was less elastin amount in CCR2-knockout mice with increased infarct size and the ejection fraction was lower compared to wild type mice. After 1 month the ejection fraction in CCR2-knockout mice was lower compared to wild type mice and the infarct size was increased.

Andrew N. Priest¹, Ilse Joubert¹, Sarah Hilborne¹, Sally Hunter¹, David J. Bowden¹, Martin John Graves¹, Trevor Baglin², Jonathan H. Gillard³, and David J. Lomas^1
1Department of Radiology, Addenbrookes Hospital and University of Cambridge, Cambridge, United Kingdom, ²Department of Haematology, Addenbrookes Hospital, Cambridge, United Kingdom, ³Department of Radiology, University of Cambridge, Cambridge, United Kingdom

MR Direct Thrombus Imaging (MR-DTI) is able to highlight acute thrombus, due to the short T1 relaxation time of met-haemoglobin. In this study, simulations and phantom measurements are used to optimise the SNR from thrombus while suppressing the blood signal. Fat suppression is particularly important for MR-DTI due to the short T1 of fat. This study also investigates the combination of MR-DTI with dual-echo Dixon imaging, allowing improved fat suppression, and thus improved depiction of thrombus, near the edge of the field of view. These methods are demonstrated in patients with acute deep vein thrombosis and carotid intraplaque haemorrhage.

Michael Lell¹, Javier Arnaiz², Denis Krause³, Luis Marti-Bonmati⁴, Manuela Aschauer⁵, Armando Tartaro⁶, Massimo Lombardi⁷, Marta Burrel⁸, Reynald Izzillo⁹, and Christian Loewe^10
1Radiology Department, University-Hospital, Erlangen, Germany, ²University Hospital Marquès de Valdecilla, Santander, Spain, ³Département de Radiologie et d'Imagerie Médicale Diagnostique et Thérapeutique, CHU Le Bocage, Dijon, France, Metropolitan, ⁴Dr Peset Hospital, Valencia, Spain, ⁵Radiology, Universitätsklinikum für Radiologie, Graz, Austria, ⁶University Gabriel d'Annuzio of Chieti-Pescara, Chieti, Italy, ⁷Clinical Physiology Institute CNR National Research Council, Pisa, Italy,⁸Hospital Clinico, Barcelona, Spain, ⁹Radiology, Centre Cardiologique du Nord, Saint Denis, France, ¹⁰Radiology, AKH Wien - Medizinische Universität Wien, Vienna, Austria

To date, no prospective randomized trial comparing peripheral CE-MRA at 3T to the reference standard DSA has been performed so far including a large patient population. This multicentre trial including 189 patients was primarily aimed to compare the degrees of agreement in stenosis detection between contrast enhanced-MRA and DSA using two different contrast agents (gadoterate meglumine (Dotarem®) or gadobutrol (Gadovist®)) inpatients with peripheral arterial occlusive disease (PAOD). This study demonstrates the value of peripheral MRA at 3T for diagnosis and treatment planning in patients suffering from PAOD without any difference between gadoterate meglumine-MRA and gadobutrol-MRA.

Kie Tae Kwon¹, Bob S. Hu^2,3, and Dwight G. Nishimura^1
1Electrical Engineering, Stanford University, Stanford, CA, United States, ²Palo Alto Medical Foundation, Palo Alto, CA, United States, ³HeartVista Inc., Los Altos, CA, United States

MR venography (MRV) is a promising alternative to the established sonography for the diagnosis of venous disease in regions largely inaccessible to ultrasound. Non-contrast-enhanced (NCE) approaches for MRV based on SSFP sequences have been of interest due to its superior capacity to generate high SNR and vascular contrast. In this work, a sliding interleaved cylinder acquisition was incorporated into an NCE magnetization-prepared 3D SSFP sequence for MRV in the lower extremities, which achieves artery-vein contrast by suppressing the arterial signal while retaining a venous flow-independent approach. In vivo studies of thighs on healthy volunteers demonstrated the feasibility of this approach.

Tilman Schubert¹, Markus Klarhöfer², Markus Aschwanden³, Tanja Haas¹, Augustinus Ludwig Jacob⁴, and Sebastian Kos^5
1Department of Radiology and Nuclear Medicine, University Hospital Basel, Basel, Basel, Switzerland, ²Siemens Switzerland Inc, Zuerich, Zuerich, Switzerland, ³Department of Angiology, University Hospital Basel, Basel, Basel, Switzerland,⁴Centre for Microtherapy, Klinik Hirslanden, Zuerich, Zuerich, Switzerland, ⁵Centre for Microtherapy, Klinik Hirslanden, Luzern, Luzern, Switzerland

High resolution, non-contrast-enhanced MRA (native SPACE) was compared with digital subtraction angiography (DSA) and contrast-enhanced MRA (ceMRA) for imaging of the pedal arteries in 11 patients with peripheral arterial occlusive disease (pAOD). A significant difference between native SPACE and ceMRA, and between native SPACE and DSA regarding vessel visibility and degree of stenosis was found. However, a comparison of native SPACE and ceMRA regarding diagnostic utility did not reveal a significant difference. DSA was superior to both MRA sequences in terms of diagnostic utility. In conclusion, native SPACE is suitable for the asessment of small vessel disease.

Samuel Fielden¹, John P. Mugler, III^1,2, Patrick Norton², Christopher Kramer^2,3, and Craig Meyer^1,2
1Biomedical Engineering, University of Virginia, Charlottesville, VA, United States, ²Radiology, University of Virginia, Charlottesville, VA, United States, ³Medicine, University of Virginia, Charlottesville, VA, United States

We have previously shown that flow-independent angiography can be performed with TSE-based sequences, as these sequences provide fast T2-weighted volumetric images. In order to achieve better arterial/venous contrast, longer echo spacings can be used to shorten the apparent T2 of venous blood. Here we utilize spiral readouts in a 3D TSE sequence in order to extend echo spacings while maintaining acquisition efficiency in order to produce fast, volumetric, non-subtractive non-contrast peripheral angiograms.

Parag Amin¹, Maria Carr², Marie Wasielewski¹, Heron Rodriguez³, Jeremy D. Collins², Robert R. Edelman⁴, and James C. Carr^2
1Radiology, Northwestern Memorial Hospital, Chicago, IL, United States, ²Radiology, Northwestern University, Chicago, IL, United States, ³Vascular Surgery, Northwestern Memorial Hospital, Chicago, IL, United States, ⁴Radiology, NorthShore University HealthSystem, Evanston, IL, United States

Comparing performance of QISS MR angiography to contrast-enhanced MR angiography of the lower extremities.

Daniel V. Litwiller¹, Dan W. Rettmann¹, Mahdi S. Rahimi², Harald Kramer³, James F. Glockner⁴, Frank R. Korosec⁵, and James H. Holmes^6
1Global Applied Science Laboratory, GE Healthcare, Rochester, MN, United States, ²Biomedical Engineering, University of Wisconsin, Madison, WI, United States, ³Radiology, University of Wisconsin, Madison, WI, United States, ⁴Department of Radiology, Mayo Clinic, Rochester, MN, United States, ⁵Radiology and Medical Physics, University of Wisconsin, Madison, WI, United States, ⁶Global Applied Science Laboratory, GE Healthcare, Madison, WI, United States

Inflow-based angiography techniques, such as time-of-flight (TOF), inflow inversion-recovery (IFIR), and quiescent-inflow single-shot (QISS), preferentially select for a single direction of vascular flow. Here, we propose an interleaved, QISS-based approach to the simultaneous acquisition of directionally-opposed arterial and venous signal in the lower extremities, which results in the formation of two independent, two-dimensional images per heartbeat. We believe this strategy may allow the detection of additional, clinically-relevant features, such as venous compression and/or thrombus without adding scan time or compromising quality and robustness of the original QISS MRA.

Andrew N. Priest¹, Ilse Joubert¹, Sarah Hilborne¹, Sally Hunter¹, David J. Bowden¹, Martin John Graves¹, Trevor Baglin², and David J. Lomas^1
1Department of Radiology, Addenbrookes Hospital and University of Cambridge, Cambridge, United Kingdom, ²Department of Haematology, Addenbrookes Hospital, Cambridge, United Kingdom

ADVANCE-MRV, a recently described method for non-contrast-enhanced venography, is able to depict veins while suppressing the signal from arteries and static tissues, by subtraction of flow-sensitised images. In regions with low flow dispersion, the venous suppression can fluctuate, leading to non-uniform signal in the venograms. This problem was previously overcome by combining multiple images with differing flow sensitisations. An alternative is to use multiple flow preparations within a single acquisition: this method is demonstrated to improve the consistency of venous suppression and the uniformity of the resultant venograms. Initial patient imaging clearly depicts femoral vein occlusion due to DVT.

Motoyuki Katayama¹, Takayuki Masui¹, Koji Yoneyama¹, Kimihiko Sato¹, Kazuma Terauchi¹, Kei Tsukamoto¹, Kenich Mizuki¹, Takayuki Suzuki¹, Mitusharu Miyoshi², and Daniel V. Litwiller^3
1Radiology, Seirei Hamamatsu General Hospital, Hamamatsu, Shizuoka, Japan, ²GE Healthcare Japan, Hino, Tokyo, Japan, ³Global Applied Science Laboratory, GE Healthcare, Rochester, MN, United States

First, we optimized the preparation time of peripheral gaining on Quiescent Interval Single Shot (QISS) MR Angiography for extremities. Second, we compared QISS MR Angiography using peripheral gating with Delta Flow MRA with QISS using peripheral pulse gating provides good image quality in the pelvis and extremities, which is equal to that with Delta Flow. When gadolinium cannot be used, with peripheral pulse gating, unenhanced MRA with QISS and Delta Flow can be used.

Matthew P. Quinn^1,2 and Ravi S. Menon^1,2
1Medical Biophysics, The University of Western Ontario, London, Ontario, Canada, ²Centre for Functional and Metabolic Mapping, Robarts Research Institute, London, Ontario, Canada

Recently, a role for abnormalities in extra-cranial veins in the pathogenesis of multiple sclerosis (MS) has been proposed. Diagnosis of this “chronic cerebrospinal venous insufficiency” (CCSVI) requires studies with ultrasound, which is foreign to the conventional assessment of MS. Alternatively, MRI is used routinely for MS imaging. Time of flight (TOF) magnetic resonance venography (MRV) can be used to produce three-dimensional venograms and is capable of determining the presence of vascular lesions. We demonstrate that measurements of IJV cross-sectional area are sufficiently reproducible across serial venograms for use in MRI-based CCSVI protocols. Moreover, robust co-registration of serial MRVs is possible.

Masaaki Akahane¹, Yasushi Watanabe¹, Naoyuki Takei², and Kuni Ohtomo^1
1Radiology, University of Tokyo Hospital, Bunkyo-ku, Tokyo, Japan, ²Global Applied Science Laboratory, GE Healthcare, Hino-shi, Tokyo, Japan

The purpose of this study was to assess feasibility and diagnostic performance of non-contrast-enhanced MR angiography of adrenal veins using respiratory-triggered axial 3D balanced SSFP sequence with frequency-selective fat-saturation pulse. 34 patients who were planned to undergo adrenal vein sampling were included in this study. Catheter venography and cone-beam CT during venography were used as gold standard for the evaluation. Right adrenal veins were visualized in 27 of 34 patients, and left adrenal veins were visualized in 32 of 34 patients. Non-contrast-enhanced MR angiography was feasible for preprocedural of adrenal vein sampling.

Robert R. Edelman¹, Shivraman Giri², Eugene Dunkle³, Mauricio Galizia³, Parag Amin³, and Ioannis Koktzoglou^3
1Radiology, NorthShore University HealthSystem, Evanston, Illinois, United States, ²Siemens Healthcare, Chicago, Illinois, United States, ³NorthShore University HealthSsytem, Evanston, Illinois, United States

We hypothesized that high undersampling factors could be used in conjunction with radial Quiescent-Inflow Single-Shot (QISS) MRA in order to accelerate data collection and enable multi-slice and body coil acquisitions. Three healthy subjects and four patients with PAD were imaged on a 1.5T MRI system. Comparing Cartesian QISS (93 lines) with single slice radial QISS (92 views), the respective image quality scores were 2.6 ± 0.4 and 2.9 ± 0.2 (p = 0.04). We have demonstrated the feasibility of radial QISS MRA with much higher undersampling factors than are achievable using a Cartesian k-space trajectory and standard parallel imaging techniques.

Gregory J. Metzger¹, Sebastian Schmitter¹, Xiufeng Li¹, Pierre-Francois Van de Moortele¹, Peter Schmitt², and Xiaoming Bi^3
1Center for Magnetic Resonance Reserach, University of Minnesota, Minneapolis, MN, United States, ²MR Application & Workflow Development, Siemens AG, Erlangen, Germany, ³Cardiovascular MR R&D, Siemens Healthcare, Chicago, IL, United States

Arterial spin labeled (ASL) 4D MRA has been shown to be a valuable method for simultaneously assessing anatomic structure and dynamic filling of cerebral arteries. Beyond improved SNR and parallel imaging performance, performing these studies at ultrahigh will improved visualization of distal vessels, especially in conditions of reduced flow, due to prolonged T1 relaxation times resulting in more persistent labeling. A dynamically applied transmit B1 (B1+) shimming strategy was employed to accommodate limitations on peak B1+, B1+ homogeneity and SAR. Initial results showing signal persistence in distal arteries are shown.

Nii Okai Addy¹, Holden H. Wu², R. Reeve Ingle¹, and Dwight G. Nishimura^1
1Electrical Engineering, Stanford University, Stanford, CA, United States, ²Department of Radiology, University of California, Los Angeles, Los Angeles, CA, United States

Although 3D non-Cartesian trajectories allow fast whole-heart coronary angiography, further improvement in speed can be achieved with parallel imaging. However, this is challenging for large 3D non-Cartesian datasets due to the high computational demand of operations such as gridding. In this work, a multi-threaded version of L1-SPIRiT is presented and tested on different undersampled variable-density trajectories showing the ability to increase image resolution while maintaining the same scan time.

Christoph Forman^1,2, Davide Piccini^3,4, Joachim Hornegger^2,5, and Michael O. Zenge^6
1Pattern Recognition Lab, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany, ²Erlangen Graduate School in Advanced Optical Technologies (SAOT), Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany,³Advanced Clinical Imaging Technology, Siemens Healthcare IM S AW, Lausanne, Switzerland, ⁴CIBM-AIT, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland, ⁵Pattern Recognition Lab, Department of Computer Science, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany, ⁶Healthcare Sector, Siemens AG, Erlangen, Germany

The experience of an extended number of volunteer experiments revealed that a respiratory motion detection by tracking the heart in SI projections can be degraded by several factors, e.g. suboptimal fat saturation, which may result in motion artefacts in the reconstructed images. By leaving the paradigm to correct for motion directly from the feedback of the projections behind, we propose a more robust method for the binning of the SI projections into respiratory phases. The robustness of the new approach was demonstrated in experiments with 10 healthy volunteers. The proposed method showed a high correlation to the conventional navigator.

Jianing Pang^1,2, Behzad Sharif¹, Reza Arsanjani¹, Louise EJ Thomson¹, John D. Friedman¹, Daniel S. Berman¹, and Debiao Li^1,3
1Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, ²Biomedical Engineering, Northwestern University, Chicago, IL, United States, ³Bioengineering, University of California, Los Angeles, CA, United States

In this work, we report a self-calibrated non-Cartesian sensitivity encoding scheme integrated with image-based motion correction for whole-heart coronary MRA. Results show that the proposed method can greatly reduce the artifact level in images with different undersampling factor, thus allows further reduction in scan time without significant sacrifice in image quality.

Fabian Hezel¹, Peter Kellman², Katharina Fuchs¹, Lukas Winter¹, Oliver Kraus¹, and Thoralf Niendorf^1,3
1Berlin Ultrahigh Field Facility (B.U.F.F.), Max-Delbrueck Center for Molecular Medicine, Berlin, Germany, ²Medical Imaging Section, National Institutes of Health / NHLBI, Bethesda, Maryland, United States, ³Experimental and Clinical Research Center, A joint cooperation between the Charité Medical Faculty and the Max-Delbrueck Center for Molecular, Berlin, Germany

This work demonstrates coronary MR angiography at ultrahigh fields. Fat suppression is achieved through fat-water separation through an Multi-echo-Dixon approach.

Bo Li¹, Li Dong², Yuchen Zhang³, Jun Li², Xiaoying Wang^4,5, Jue Zhang^1,5, and Jing Fang^1,5
1College of Engineering, Peking University, Beijing, China, ²Department of Radiology, Anzhen Hospital, Capital Medical University, Beijing, China, ³Department of Cardiology, Anzhen Hospital, Capital Medical University, Beijing, China, ⁴Department of Radiology, Peking University First Hospital, Beijing, China, ⁵Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China

In this work, an additional time delay (TD) was introduced to 3D MERGE sequence to improve signal intensity. Compressed sensing (CS), an undersampling technique, was used to maintain a constant scan time. nine healthy volunteers were recruited for this study. Results showed: (1) Significant improvements in vessel wall SNR and wall-lumen CNR were found; (2) Effective blood suppression can be achieved; (3) Good agreements of wall area and lumen area were also obtained between the proposed technique and the existing MRI protocol.

Meihan Wang¹, Christopher Kramer^2,3, and Craig Meyer^1,2
1Biomedical Engineering, University of Virginia, Charlottesville, VA, United States, ²Radiology, University of Virginia, Charlottesville, VA, United States, ³Medicine, University of Virginia, Charlottesville, VA, United States

In the abstract we have implemented a novel blood suppression method called DANTE preparation pulses in coronary artery studies. It supposed to be able to generate high contrast images while maintaining SNR. We have tested its performance with 2D multi-slice and 3D spiral GRE sequences. Traditional double inversion recovery sequence was provided as a reference. The results show that CNR in DANTE prepared images is higher than the ones with DIR, with little SNR loss, and with DANTE pulses, the imaging strategy is more flexible and robust.

Shuo Chen¹, Hua Guo¹, Wenchuan Wu¹, Xihai Zhao¹, Chun Yuan^1,2, and Huijun Chen^1
1Center for Biomedical Imaging Research & Department of Biomedical Engineering, Tsinghua University, Beijing, China, ²Department of Radiology, University of Washington, Seattle, WA, United States

Compositional characteristics of atherosclerotic plaque are believed to be linked to plaque vulnerability. As such, investigation of key plaque features might be helpful for stroke prevention. Previous studies suggested that diffusion weighted imaging (DWI) might be useful for detection of lipid-rich necrotic core. We proposed a high resolution DWI method using variable density spiral (DW-VDS) for carotid plaque detection. We found that carotid vessel wall and plaque can be successfully delineated at both diffusion weighted images and ADC maps, suggesting that DW-VDS might be an alternative method for composition identification of atherosclerotic plaque.

Xu Han¹, Jianming Cai¹, Danqing Liu¹, Lin Ma¹, Youquan Cai¹, and Xihai Zhao^2
1Department of Radiology, PLA General Hospital, Beijing, China, ²Center for Biomedical Imaging Research & Department of Biomedical Engineering, Tsinghua University, Beijing, China

This study investigated the correlation of atherosclerotic disease between intracranial and extracranial carotid arteries using MR multicontrast, high resolution, black-blood vessel wall imaging. We found that there was significant correlation between intracranial and extracranial atherosclerotic diseases. We also found that there was significant correlation for severity of atherosclerotic disease between intracranial and extracranial circulations. Our findings further compel the evidence that atherosclerosis is a systemic disease that usually impacts multiple vascular territories and suggest that atherosclerotic plaque at extracranial carotid artery might be an indicator for either presence or severity of intracranial atherosclerosis.

J. Kevin DeMarco¹, Hideki Ota², David Zhu¹, William Kerwin³, and Chun Yuan^3
1Michigan State University, East Lansing, MI, United States, ²Diagnostic Radiology, Tohoku University Hospital, Sendai, Miyagi, Japan, ³University of Washington, Seattle, WA, United States

The purpose of this study was to test the feasibility of automated segmentation of two non-contrast MR sequences to predict the size of necrotic-core identified by manual segmentation of multi-contrast carotid plaque MRI. Forty-eight arteries from 26 consecutive patients were analyzed. Automated segmentation identified all 16 carotid plaques harboring moderate/large necrotic-core with 6 additional false positive studies and excluded 54% of the carotid arteries as not having significant necrotic core. The addition of 3D IR-FSPGR to clinical MRA evaluation of carotid stenosis could help identify patients potentially harboring moderate/large necrotic-core who might be candidates for new aggressive lipid-lowering therapies.

Huijun Chen¹, Pathmaja Paramsothy², Alice Dowdy², Arthi Thirumalai², Sarah Prager², Xihai Zhao¹, Xue-Qiao Zhao², Edward Gill², and William Kerwin^2
1Tsinghua University, Beijing, Beijing, China, ²University of Washington, Seattle, WA, United States

The metabolic syndrome (MetS), a manifestation of insulin resistance, is associated with independent increased risk of CVD. One of the early manifestations of MetS on the arterial wall is endothelial dysfunction, which may lead to altered contrast agent kinetics in DCE MRI. Because of the small size of the vessel wall early in the atherosclerosis, blood suppressed DCE protocols are required, precluding extraction of the AIF for kinetic modeling. In this study, we sought to test the ability of black-blood DCE-MRI plus reference region model to study contrast agent kinetics in MetS patients drawn from a population of premenopausal women.

Chengcheng Zhu¹, Andrew J. Patterson¹, Martin John Graves¹, and Jonathan H. Gillard^1
1University Department of Radiology, University of Cambridge, Cambridge, Cambridgeshire, United Kingdom

Improved motion-sensitized driven-equilibrium (iMSDE) preparation provides better blood suppression than traditional spatial saturation and double inversion-recovery (DIR) methods in carotid vessel wall imaging. However, iMSDE preparation can cause signal loss, mostly due to eddy current effects and B1+ inhomogeneity. We have investigated the CNR and SNR performance of iMSDE prepared T1w and T2w MRI using composite RF pulses and sinusoidal gradients.

Chris A. Cocosco¹, Julia Geiger², Frederik Testud¹, Adriana Komancsek¹, Thorsten Bley³, Matthias Weigel¹, Maxim Zaitsev¹, Bernd Jung¹, Jürgen Hennig¹, and Ute Ludwig^1
1Dept. of Radiology, Medical Physics, University Medical Center Freiburg, Freiburg, Germany, ²Dept. of Radiology, University of Freiburg, Freiburg, Germany, ³Dept. of Radiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany

Giant-cell arteritis is the most common vasculitis. MRI is a powerful tool for the depiction of the inflamed cranial arteries, but in a clinical setting this requires sub-mm resolution and fast measurement times. We evaluated the performance of two high-end receive array coils for the imaging of superficial temporal and occipital arteries’ wall in healthy volunteers on a 3T clinical scanner. The results show clearly improved imaging performance is achieved with the more focused coverage of an experimental 95-channel head coil compared to the commercially available high-end head coil.

Chengcheng Zhu¹, Andrew J. Patterson¹, Jin Zhu², Martin John Graves¹, and Jonathan H. Gillard^1
1University Department of Radiology, University of Cambridge, Cambridge, Cambridgeshire, United Kingdom, ²Department of Computer Science, Peking University, Beijing, China

Atherosclerotic plaques presenting within extra- and intra-cranial arteries are known to be risk factors for subsequent stroke. High resolution artery vessel wall MRI can visualize high-risk morphologic factors of plaques in vivo and help patient risk stratification. 3D CUBE has demonstrated a high SNR efficiency as well as intrinsic black-blood effects in vessel wall imaging. Improved motion-sensitized driven-equilibrium (iMSDE) preparation provides better blood suppression than traditional spatial saturation and double inversion-recovery (DIR) methods. This study investigated the automatic segmentation and analysis of carotid and middle cerebral artery (MCA) using T1w/T2w CUBE combined with iMSDE blood suppression.

Xinwei Shi¹, Xiao Wang², Feng Huang³, Kui Ying⁴, and Chun Yuan^5
1Department of Biomedical Engineering, Tsinghua University, Beijing, China, ²Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States, ³Philips Healthcare, Gainesville, FL, United States, ⁴Department of Engineering Physics, Tsinghua University, Beijing, China, ⁵Department of Radiology, University of Washington, Seattle, WA, United States

In this work, a new method named slice GRAPPA (sGRAPPA) is proposed for accelerating carotid imaging which used to be challenging for traditional fast imaging techniques due to its low SNR in region of interest. sGRAPPA utilizes k-space data correlation in slice dimension as well as phase encoding dimension, and provides better preserved SNR and improved structure similarity than traditionally used GRAPPA in phantom and in-vivo experiments.

Michael C. Langham¹, Cheng Li¹, Erin K. Englund¹, and Felix W. Wehrli^1
1University of Pennsylvania, Philadelphia, Pennsylvania, United States

SSFP-echo is known to have low vascular signal but has not been considered for vessel-wall imaging. Its efficiency and inherent signal attenuation of moving spins due to phase incoherence of echo pathways make it potentially attractive for black-blood imaging. Here, we demonstrate the potential for 3D vessel-wall imaging with water-selective 3D SSFP-echo with double-inversion recovery (DIR-SSFPe). The use of DIR minimizes the enhancement of magnetization via inflow effect and provides additional time for the tissue’s Mz to relax during the inversion time. In vivo results support the proposed approach as a possible alternative to 3D vessel-wall imaging of carotid arteries.

Gabriele Bonanno^1,2, David Brotman^1,2, and Matthias Stuber^1,2
1Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Vaud, Switzerland, ²Center for Biomedical Imaging (CIBM), Lausanne, Vaud, Switzerland

A novel extension of phase-sensitive dual inversion recovery (PS-DIR) is proposed, implemented and tested for carotid vessel wall imaging. By probing the statistical distribution of the phase image carotid lumens are automatically segmented and their residual signal suppressed. The proposed PS-DIR technique was tested in healthy adult subjects and provided effective blood-suppression over a broad range of inversion times enhancing lumen-to-vessel wall contrast and vessel wall sharpness in the carotid arteries. Preliminary results of a multi-slice implementation showed to improve volumetric coverage with a 3-fold acceleration in scanning time.

Niranjan Balu¹ and Chun Yuan^1
1Radiology, University of Washington, Seattle, Washington, United States

Comparison of pre and post-gadolinium contrast black-blood MRI is required for accurate identification of atherosclerotic plaque components such as lipid-rich necrotic core. Obtaining both pre and post-contrast MRI with identical imaging parameters is critical to distinguish plaque components based on their contrast uptake. Adequate blood-suppression in post-contrast 3D black-blood MRI is challenging due to shortening of blood T1 post-contrast and the requirement of large coverage and short scan time. We describe a 3D isotropic black-blood imaging for large-coverage black-blood MRI pre and post-contrast with identical imaging parameters and compare its performance to an existing 2D quadruple inversion recovery sequence.

Tingting Wu¹, Huijun Chen¹, Jinnan Wang², Juan Wei³, Feiyu Li⁴, and Chun Yuan^1,5
1CBIR, School of Medicine, Tsinghua University, Beijing, China, ²Clinical Sites Research Program, Philips Research North America, Briarcliff Manor, NY, United States, ³Philips Research Asia, Shanghai, China, ⁴Peking University First Hospital, Beijing, China, ⁵Dept. of Radiology, University of Washington, Seattle, WA, United States

In this study, a conversion-free interleaved black blood and bright blood sequence (cfIBBI) is developed for Dynamic Contrast Enhanced (DCE) MRI of vessel wall perfusion of early lesion, which has high spatial resolution and excellent blood suppression in black blood image as well as high temporal resolution in bright blood image for AIF. Moreover, the signal intensities of the black-blood and bright-blood images are comparable and can be used directly in kinetic analysis without conversion.

Andrew J. Coristine^1,2, Ruud B. van Heeswijk^1,2, and Matthias Stuber^1,2
1CIBM-CVMR, Centre Hospitalier Universitaire Vaudois, Lausanne, VD, Switzerland, ²FBM, Université de Lausanne, Lausanne, VD, Switzerland

At high field, B₀ and B₁ inhomogeneities may complicate fat saturation strategies, such as CHEmically Selective Saturation (CHESS) pulses, which are dependant on precise excitation angles and precessional frequencies. These fat saturation pulses, which are necessary for unambiguous visualization of cardiac anatomy, are often used in conjunction with magnetization preparation modules, such as T₂ Preparation (or T₂-Prep), to improve blood/myocardium contrast. By modifying an adiabatic T₂-Prep to be water-selective, off-resonance frequencies can be suppressed - adding an intrinsic fat signal attenuation that is less sensitive to B₀ and B₁ inhomogeneities - while preserving the T₂-Prep's added contrast. Numerical simulations, phantom validation, and initial in vivo results are presented.

Adrian Lam¹, Luis F. Mora-Vieira², Michael Lloyd², and John N. Oshinski^1,2
1Georgia Institute of Technology, Atlanta, GA, United States, ²Emory University, Atlanta, GA, United States

The LV lead implantation location for Cardiac Resynchronization Therapy is determined by imaging the coronary venous anatomy with catheter-based retrograde venography during the implantation procedure, preventing pre-procedural planning. Current studies have shown that a modified whole heart MRA which combines a centric-ordering k-space scheme and a slow infusion of gadolinium is capable of imaging the coronary venous anatomy. In this work, we show that this MR sequence is capable of visualizing over 90% of the coronary venous anatomy when compared to the veins visible by retrograde venography.

Mehdi H. Moghari¹, Markus Henningsson², Sébastien Roujol³, Kraig V. Kissinger³, David Annese¹, Warren J. Manning^3,4, Tal Geva¹, Andrew J. Powell¹, and Reza Nezafat^3
1Department of Cardiology, Boston Children’s Hospital, Boston, MA, United States, ²King’s College London, London, United Kingdom, ³Cardiovascular Division, Beth Israel Deaconess Medical Center, Boston, MA, United States, ⁴Radiology Department, Beth Israel Deaconess Medical Center, Boston, MA, United States

A novel technique was developed to correct for respiratory-induced heart motion during 3D MR coronary angiography. Phantom and human subject data are presented to validate the proposed method.

Jianing Pang^1,2, Hsin-Jung Yang^1,3, Yibin Xie^1,3, Rohan Dharmakumar¹, and Debiao Li^1,3
1Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, ²Biomedical Engineering, Northwestern University, Chicago, IL, United States, ³Bioengineering, University of California, Los Angeles, CA, United States

In this work we propose an automatic processing strategy for respiratory self-navigation based on principal component analysis. Numerical simulation and in vivo study were performed. Results show that the proposed method accurately captures the simulated motion, and when applied to the in vivo coronary MRA dataset one is able to reduce motion blurring from phase correction using the detected translational motion.

Simone Coppo^1,2, Davide Piccini^3,4, Gabriella Vincenti⁵, Didier Locca⁵, Juerg Schwitter⁵, Piergiorgio Tozzi⁵, and Matthias Stuber^1,2
1Departiment of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland, ²Center for Biomedical Imaging (CIBM), Lausanne, Switzerland, ³Advanced Clinical Imaging Technology, Siemens Healthcare IM S AW, Lausanne, Switzerland, ⁴Departiment of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL) / Center for Biomedical Imaging (CIBM), Lausanne, Switzerland, ⁵Cardiac Magnetic Resonance Center and Cardiology Service, University Hospital of Lausanne (CHUV), Lausanne, Switzerland

Self-Navigated 3D radial whole heart sequence was successfully applied for the first time in patients with coronary artery bypass grafts (CABG) to visualize the complex morphology of the CABG.

Davide Piccini^1,2, Gabriele Bonanno², Giulia Ginami^2,3, Arne Littmann⁴, Michael O. Zenge⁴, and Matthias Stuber^2
1Advanced Clinical Imaging Technology, Siemens Healthcare IM S AW, Lausanne, Switzerland, ²Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL) / Center for Biomedical Imaging (CIBM), Lausanne, Switzerland, ³Department of Information Engineering, University of Padova, Padova, Italy, ⁴MR Application and Workflow Development, Healthcare Sector, Siemens AG, Erlangen, Bayern, Germany

In standard respiratory self-navigated (SN) whole heart coronary MRA, the reference position for motion correction is usually selected at the very beginning of the image data acquisition. In this work, the relationship between the choice of the reference and objective image quality was investigated. End-expiration, end-inspiration and mean respiratory position were considered as possible candidate reference respiratory positions for SN whole-heart coronary MRI and tested in 11 volunteers. Vessel sharpness of the mid segment of the left anterior descending coronary artery was computed for every dataset. End-expiration was found to significantly improve vessel sharpness, when compared to the end-inspiration.

Giorgos Papanastasiou^1,2, Lucy Kershaw¹, Michelle Williams², Mark Dweck², Shirjel Alam², Saeed Mirsadraee¹, Calum Gray¹, Tom MacGillivray¹, David C. Newby^1,2, and Scott I. Semple^1,2
1Clinical Research Imaging Center, University of Edinburgh, Edinburgh, United Kingdom, ²Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, United Kingdom

Modern advances in magnetic resonance (MR) and computed tomography (CT) perfusion imaging techniques have developed methods for myocardial perfusion assessment. However, individual imaging techniques present limitations that are possible to be surpassed by a multimodality cross-validation of perfusion imaging and analysis. We calculated the absolute myocardial blood flow (MBF) in MR using a Fermi function and the transmural perfusion ratio (TPR) in CT perfusion data in a patient with coronary artery disease (CAD). Comparison of MBF and TPR results showed good correlation emphasizing a promising potential to continue our multimodality perfusion assessment in a cohort of patients with CAD.

Christophe Schülke^1,2, Sébastien Roujol¹, Murilo Foppa¹, Ernest V. Gervino¹, Kraig V. Kissinger¹, Beth Goddu¹, Sophie J. Berg¹, Sebastian Kozerke², Warren J. Manning^1,3, and Reza Nezafat^1
1Medecine, BIDMC / Harvard Medical School, Boston, MA, United States, ²Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland, ³Radiology, BIDMC / Harvard Medical School, Boston, MA, United States

Physiologic stress provides unique information regarding a patient’s exercise capacity and hemodynamic response to exercise. To perform post physiologic stress CMR perfusion, we employed an MR-compatible supine ergometer mounted on the scanner table. In our experience, coil sensitivity maps are generally corrupted due to patient motion during exercise and significant respiratory motion is encountered during the CMR perfusion acquisition. To allow CMR perfusion with elevated heart rate image acquisition should be shortened. The aim of this study was to compare reconstruction methods for accelerated CMR perfusion immediately post physical stress.

Tamer A. Basha¹, Sébastien Roujol¹, Kraig V. Kissinger¹, Beth Goddu¹, Sophie J. Berg¹, Warren J. Manning^1,2, and Reza Nezafat^1
1Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, United States, ²Radiology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, United States

In patients with coronary artery disease, stress CMR perfusion allows assessment of the functional significance of stenosis. In this sequence, respiratory motion would adversely impact the image quality. In this study, we propose to use an optimal leading navigator, placed immediately before each 2D slice acquisition, for tracking of respiratory motion and updating the slice location in real-time for free-breathing CMR perfusion after physical stress.

Behzad Sharif¹, Rohan Dharmakumar¹, Troy LaBounty¹, Chrisandra Shufelt², Louise EJ Thomson², Noel Bairey Merz², Daniel S. Berman², and Debiao Li^1
1Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, ²Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States

A major limitation for first-pass perfusion myocardial MRI is the presence of the so-called dark rim artifacts (DRAs), which may confound interpretation and diagnosis of subendocardial perfusion defects. A major cause of DRAs is known to be Gibbs ringing along the subendocardial border. In this work we demonstrate that projection imaging significantly reduces the prevalence and spatial extent of subendocardial DRAs in first-pass perfusion imaging, compared to conventional Cartesian techniques.

Johannes Tran-Gia¹, Thomas Troalen², Herbert Köstler¹, and Frank Kober^2
1Institute of Radiology, University of Würzburg, Würzburg, Germany, ²Centre de Résonance Magnétique Biologique et Médicale (CRMBM), UMR CNRS N°7339, Faculté de Médecine, Aix-Marseille Université, Marseille, France

A model-based algorithm for the reconstruction of Look-Locker FAIR Gradient Echo Cartesian ASL datasets is presented. By incorporating a signal model into the image reconstruction, parameter mapping can be performed from highly undersampled k-spaces acquired after FAIR magnetization preparation. In conjunction with a time log of the inversion times of all acquired phase encoding steps, this allows to take into account any variations in inversion time during the experiment, highly improving the temporal resolution of the obtained T1. The functionality of the algorithm and the accuracy of the quantified parameters in comparison to the conventional reconstruction method are demonstrated in-vivo.

Lukas Wissmann¹, Johannes F.M. Schmidt¹, and Sebastian Kozerke^1
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland

The development of novel cardiac MRI methodology requThe development of novel cardiac MRI methodology requires simulation of both anatomical and functional information. To date, most numerical and physical phantoms tend to oversimplify anatomy and/or physiology. This study proposes a realistic 4D numerical phantom for quantitative myocardial perfusion MRI based on the XCAT model. It incorporates information about anatomy as well as dynamic contrast enhancement and, optionally, cardiac and respiratory motion. As an example application, the impact of dose and T1 uncertainty on myocardial blood flow quantification are studied.

Sébastien Roujol¹, Tamer A. Basha¹, Christophe Schülke^1,2, Martin Buehrer^1,2, Warren J. Manning^1,3, and Reza Nezafat^1
1Medecine, BIDMC / Harvard Medical School, Boston, MA, United States, ²Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland, ³Radiology, BIDMC / Harvard Medical School, Boston, MA, United States

In cardiac MR perfusion after physiological stress a significant respiratory motion is encountered and coil sensitivity maps are generally corrupted due to patient motion during exercise. Compressed sensing (CS) is an alternative acceleration technique that enables high acceleration even without exploiting temporal dimension or need for coil maps. However, iterative CS reconstruction is lengthy, performed off-line and is not usually integrated into the workflow of a clinical scan. In this study, a GPU-based workflow and a CPU cluster-based workflow have been developed and compared to accelerate the iterative CS reconstruction and minimize the overall reconstruction latency.

Peter Bernhardt¹, Thomas Walcher, Katharina Ikuye, Wolfgang Rottbauer, Volker Rasche, and Jochen Wöhrle
¹University of Ulm, Ulm, BW, Germany

Quantitative perfusion reserve of 1.5 and 3 Tesla cardiac magnetic resonance imaging was compared against the angiographic standard of fractional flow reserve. 34 patients underwent imaging at both field strengths including adenosine-perfusion, and within 72 hours invasive coronary angiography including fractional flow reserve in all major coronary arteries. Our results suggest 3 Tesla perfusion imaging to be superior to 1.5 Tesla for the detection of significant coronary artery stenosis.

Shona Matthew¹, Deirdre B. Cassidy¹, Stephen J. Gandy^2,3, Patricia Martin³, and J. Graeme Houston^1,3
1Cardiovascular & Diabetes Imaging, University of Dundee, Dundee, Angus, United Kingdom, ²NHS Tayside Medical Physics, Dundee, Angus, United Kingdom, ³NHS Tayside Clinical Radiology, Dundee, Angus, United Kingdom

This study sought to enhance the work detailed in Poster I (4458) by investigating if contrast agent dose/kg, heart rate, ejection fraction, left ventricular mass and signal intensity in the blood pool of the LV during FPPI impact on the peak signal intensity detected in the myocardium during initial enhancement in a cohort of normal healthy volunteer and a cohort of cardiac patients.

Liang Zhong¹, Seyed Saeid Khalafvand², Yin Kwee Ng², and Rusan Tan^1
1National Heart Centre Singapore, Singapore, Singapore, Singapore, ²Nanyang Technological University, Singapore, Singapore, Singapore

Surgical ventricular restoration is designed to normalize ventricular shape and volume. However, the STICH (Surgical Treatment for Ischemic Heart Failure Trial) found no difference in clinical benefit between CABG and CABG+SVR. It was speculated that improved ejection fraction was balanced by worsened diastolic function. Ventricular 3D flow provides comprehensive assessment of ventricular diastolic and systolic function. In this study, we are aiming to assess 3D flow in an end-stage heart failure patient before and 4-month after SVR using the combined advanced MRI and CFD.

Kezhou Wang¹, Xinjian Du², Wei Sun³, Hagai Ganin⁴, Yi Sui^4,5, Lauren Ostergren¹, Fady T. Charbel⁶, William G. Bradley⁷, and Xiaohong Joe Zhou^8,9
1VasSol Inc., River Forest, IL, United States, ²Neurosurgery, University of Illinois at Chicago, Chicago, IL, United States, ³GE Healthcare, Waukesha, WI, United States, ⁴Center for MR Research, University of Illinois Hospital & Health Sciences System, Chicago, IL, United States, ⁵Department of Bioengineering, University of Illinois Hospital & Health Sciences System, Chicago, IL, United States, ⁶University of Illinois at Chicago, Chicago, IL, United States, ⁷Department of Radiology, UCSD Medical Center, San Diego, CA, United States, ⁸Center for MR Research, University of Illinois at Chicago, Chicago, IL, United States, ⁹Departments of Radiology, University of Illinois at Chicago, Chicago, IL, United States

Quantitative flow measurement of the cerebrospinal fluid (CSF) through the sylvian aqueduct is important for diagnostic and therapeutic decisions in communicating hydrocephalus. Accurate and reliable flow quantification of CSF has been challenging because of the very low flow rate as well as flow reversal within a cardiac cycle. In this study, an MR method based on phase contrast has been developed, optimized, and validated in a flow phantom and healthy human volunteers at 3 Tesla. The quantitative flow error was confined within 8%, and the net flow rates were determined to be between 3.6 and 6.6 ¦ÌL/cycle, which agree with the literature values obtained using alternative techniques. The ability of accurately and reliably measuring CSF flow is expected to enable future studies in patients with communicating hydrocephalus.

Julio Garcia¹, Romain Capoulade², Lyes Kadem³, Eric Larose², and Philippe Pibarot^2
1Radiology, Northwestern University, Chicago, Illinois, United States, ²Laval University, Quebec, Quebec, Canada, ³Concordia University, Montreal, Quebec, Canada

The analysis of aortic valve kinetics during systole could provide incremental prognostic information beyond what is obtained for the standard valve effective orifice area. The aims of this study were to measure aortic valve opening and closing kinetic by cardiovascular magnetic resonance and to examine their association with markers of poor prognosis in patients with aortic stenosis.

Julio Garcia¹, Michael Markl^1,2, Susanne Schnell¹, Pegah Entezari¹, Riti J. Mahadevia¹, Can Wu¹, Chris Malaisrie³, Philippe Pibarot⁴, James C. Carr¹, and Alex J. Barker^1
1Radiology, Northwestern University, Chicago, Illinois, United States, ²Biomedical Engineering, Northwestern University, Chicago, Illinois, United States, ³Division of Cardiac Surgery, Northwestern University, Chicago, Illinois, United States,⁴Department of Medicine, Laval University, Quebec, Quebec, Canada

Valve aortic stenosis (AS) is the most common cause of valvular replacement. The AS severity is mainly evaluated by transthoracic Doppler echocardiography (TTE) by measuring transvalvular velocity gradients and valve effective orifice area (EOA). In particular, valve EOA has high variability when measured by TTE. 3D time-resolved phase contrast MRI with 3-directional velocity encoding may improve EOA estimation by leveraging the advantages of a novel jet shear layer detection (JSLD) method for estimating valve EOA. The objective of this study was to validate 4D flow MRI-based EOA estimation using an in-vitro stenosis phantom and in-vivo measurements of the JSLD-determined EOA.

Shin-Lei Peng¹, Hsu-Hsia Peng¹, Tao-Chieh Yang², Jee-Ching Hsu³, Yi-Chun Wu⁴, and Fu-Nien Wang^1
1Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan, ²Department of Neurosurgy, Chang Gung Memorial Hospital, Taoyuan, Taiwan, ³Department of Anesthesiology, Chang Gung Memorial Hospital, Taoyuan, Taiwan, ⁴Animal Molecular Center, Chang Gung Memorial Hospital, Taoyuan, Taiwan

This study concentrated on the wall shear stress (WSS) of common carotid arteries (CCA) in the spontaneously hypertensive rat (SHR) via phase-contrast MRI. The reproducibility of measured WSS and regional variations of WSS at vascular segment were also computed. The WSS in the bifurcation of CCA (CCAbifur ) of SHR was significantly lower than that in the normotensive Wistar Kyoto (WKY) rats. Reproducibility measurements of intra-observer and intra-scan exhibited good agreements. Furthermore, relative lower WSS at the posterior of CCAbifur was observed in SHR. The feasibility and reproducibility of WSS measurements could benefit longitudinal studies on SHR.

Christopher K. Macgowan¹, Katherine Chan², Suzanne Laughlin³, Stephanie Khan⁴, Ruth Ann Marrie⁵, and Brenda Banwell^4
1Medical Biophysics, University of Toronto / Hospital for Sick Children, Toronto, ON, Canada, ²University of Toronto / Hospital for Sick Children, Toronto, ON, Canada, ³Medical Imaging, University of Toronto / Hospital for Sick Children, Toronto, ON, Canada, ⁴Pediatrics (Neurology), University of Toronto / Hospital for Sick Children, Toronto, ON, Canada, ⁵Internal Medicine (Neurology) and Community Health Sciences, University of Manitoba, Winnipeg, MB, Canada

Using phase-contrast MRI, we have quantified cerebral blood flow in pediatric subjects with multiple sclerosis (N=26) versus age-matched controls (N=26). This study establishes reference values for normal pediatric flow for future neurological studies. Arterial and venous flow measurements were highly reproducible within individuals. However, inter-subject variability in venous flows underscores the difficulty of attributing pathological significance to individual venous flows.

Elizabeth Janus Nett¹, Leonardo Rivera¹, Sylvana García-Rodríguez², Alejandro Roldán-Alzate³, Oliver Wieben^1,3, and Kevin M. Johnson^1
1Medical Physics, University of Wisconsin, Madison, Wisconsin, United States, ²Mechanical Engineering, University of Wisconsin, Madison, Wisconsin, United States, ³Radiology, University of Wisconsin, Madison, Wisconsin, United States

In this study, we compared 4D Flow MRI pressure measurements in a stenosis phantom with pressure catheter measurements and computation fluid dynamics (CFD). Pressure gradients calculated from 4D PC MRI data were comparable to those obtained from pressure probe and CFD. Pressures differences calculated using the Navier-Stokes and Bernoulli methods were also compared for 4D Flow and CFD data and differences as large as 18% were found.

Octavia Bane^1,2, Sanjiv J. Shah³, Michael J. Cuttica⁴, Jeremy D. Collins¹, Senthil Selvaraj⁵, Christoph Guetter⁶, James C. Carr¹, and Timothy J. Carroll^1,2
1Feinberg School of Medicine, Radiology, Northwestern University, Chicago, IL, United States, ²Biomedical Engineering, Northwestern University, Evanston, IL, United States, ³Feinberg School of Medicine, Cardiology, Northwestern University, Chicago, IL, United States, ⁴Feinberg School of Medicine, Pulmonary Care, Northwestern University, Chicago, IL, United States, ⁵Feinberg School of Medicine, Northwestern University, Chicago, IL, United States, ⁶Corporate Research, Siemens Corporation, Princeton, NJ, United States

Pulmonary hypertension (PH) is a disease of the pulmonary vasculature, with subtypes pulmonary arterial and pulmonary venous hypertension, usually diagnosed by right-heart catheterization (RHC). We propose a method to measure several cardiopulmonary parameters of interest in PH, non-invasively by MRI. The parameters are subsequently used to calculate pulmonary artery pressure waveforms according to the two element windkessel model . We validated our approach in a study of 8 consecutive patients with suspected PH (mean pulmonary arterial pressure, mPAP>25 mmHg), who underwent RHC, Doppler echocardiography and cardiac MRI. We found no statistically significant difference between RHC and MRI.

Gustavo Maia Queiroz Mendonça¹ and Joao L. A. Carvalho^1
1Department of Electrical Engineering, University of Brasília, Brasília, DF, Brazil

Real-time spiral phase contrast MRI is uniquely capable of non-invasively measuring the stroke volume associated with each individual heartbeat. The quality of these measurements depends on how good the segmentation of the interface between aortic wall and lumen is. Such process is hampered by the low-resolution and low-contrast nature of real-time images. Image segmentation using traditional techniques has proven inconsistent. We propose a novel model-based approach, which focuses on separating the aortic flow from neighboring flows, instead of aiming a millimetrically-accurate segmentation of the wall–lumen interface. This approach is robust, even when this interface is not visually distinguishable.

Gabriel L. S. L. Oliveira¹ and Joao L. A. Carvalho^1
1Department of Electrical Engineering, University of Brasília, Brasília, DF, Brazil

Fourier velocity encoding (FVE) is useful in the assessment of vascular and valvular stenosis and intravascular wall shear stress, as it eliminates partial volume effects that may cause loss of diagnostic information in more conventional phase-contrast MRI. FVE shows great potential for compressed sensing acceleration, due to its high dimensionality and intrinsic sparseness in image domain. In this work, we investigate other sparse representantions for FVE data, using a five-dimensional (x,y,z,v,t) FVE dataset of the neck (focusing on carotid flow). Several combinations of separable transforms were evaluated. Two promising combinations of transforms are proposed.

Rizwan Ahmad¹, Ning Jin^1,2, Yu Ding¹, and Orlando P. Simonetti^1
1The Ohio State University, Columbus, OH, United States, ²Siemens Medical Solutions, Columbus, OH, United States

The purpose of this work is to develop and validate a new approach to deriving blood velocity estimates from phase-contrast MRI data that improves temporal resolution and reduces artifacts without increasing acquisition time. The proposed method is based on the direct inversion of the forward model, where all measurements across time are jointly processed, pixel-by-pixel. Here, each measurement is correctly assumed to be acquired at a unique instant of time; this is a departure from the standard approach where each four consecutive measurements across time are processed together and treated as if they were acquired simultaneously.

Bradley D. Allen¹, Alex J. Barker¹, Julio Garcia¹, Maya Gabbour², Miachael Markl^1,3, Cynthia K. Rigsby^1,2, and Joshua D. Robinson^4,5
1Department of Radiology, Northwestern University, Chicago, IL, United States, ²Department of Medical Imaging, Ann & Robert H Lurie Children's Hospital of Chicago, Chicago, IL, United States, ³Department of Biomedical Engineering, Northwestern University, Chicago, IL, United States, ⁴Department of Pediatrics, Northwestern University, Chicago, IL, United States, ⁵Department of Cardiology, Ann & Robert H Lurie Children’s Hospital of Chicago, Chicago, IL, United States

The aim of the current study is to assess the impact of aortic coarctation on aortic 3D blood flow characteristics in a cohort of pediatric, young adult, and adult patients compared to a control group without coarctation, as matched for age, valve morphology and aortic diameter. Results demonstrate that the presence of coarctation or coarctation repair alters blood flow hemodynamics along the entire thoracic aorta. The coarctation group had significantly higher grade helical flow in all regions of the aorta, and the subgroup of non-repaired coarctation had higher grade helical flow than repaired coarctation.

Paul Kokeny¹, Jing Jiang^2,3, and Ewart Mark Haacke^2,3
1Biomedical Engineering, Wayne State University, Detroit, Michigan, United States, ²Radiology, Wayne State University, Detroit, Michigan, United States, ³MRI Institute for Biomedical Research, Detroit, MI, United States

A mathematical analysis of the sources of error present in PC-MRI was performed in order to study the effects that vessel segmentation boundary size has on flow quantification error. The analysis concluded that an undersized boundary, missing vessel pixels, will result in greater flow error than an oversized boundary, with partial volume error. Four automatic vessel segmentation algorithms were tested and compared using cine PC-MRI simulations that mimic the cardiac cycle. The results from this testing supported the theory presented and demonstrated that one of the algorithms stood out as a fast and accurate way to quantify flow.

Christian Binter¹, Robert Manka^1,2, Simon H. Suendermann³, Verena Knobloch¹, and Sebastian Kozerke^1,4
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland, ²Dept. of Cardiology, University Hospital Zurich, Zurich, Switzerland, ³Division of Cardiovascular Surgery, University Hospital Zurich, Zurich, Switzerland,⁴Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom

Phase-contrast MRI offers the possibility to obtain both velocities and Turbulent Kinetic Energy, making it possible to quantify the energy loss due to aortic stenosis. In this work patients and age-matched controls are compared and test-retest variability is investigated. 4D flow measurements with multiple encoding velocities in the aortic arch of 3 patients and 18 healthy volunteers were performed. The results show that the physiological range of TKE in the ascending aorta shows only little variation with age and significant differences between patients and healthy controls were found.

Patrick Winter¹, Eberhard Rommel¹, Wolfgang Rudolf Bauer², Peter M. Jakob^1,3, and Volker Herold^1
1Dept. of Experimental Physics 5, University of Würzburg, Würzburg, Bavaria, Germany, ²Medizinische Klinik und Poliklinik I, Universitätsklinikum Würzburg, Würzburg, Germany, ³Magnetic Resonance Bavaria, Würzburg, Bavaria, Germany

In this work, we introduce a retrospectively triggered PC-FLASH sequence with a radial sampling for a robust measurement of the local pulse-wave-velocity (PWV) in the murine abdominal aorta. The sequence was tested on a 17.6T small animal system on mice. A Navigator signal was extracted from the k-space center and used for the retrospective reconstruction of movie frames of the aortic motion. The PWV was determined using the QA-method. The results were compared with a prospectively triggered radial PWV measurement using a pneumatic measurement of the thoracic motion as trigger signal. The PWV value obtained with the retrospective measurement is in good accordance with the value determined with the triggered acquisition.

Guanzhong Liu¹, Kezhou Wang², Xinjian Du³, Yi Sui^1,4, Michael P. Flannery¹, Fady T. Charbel⁵, Nadera Sweiss⁶, and Xiaohong Joe Zhou^1,7
1Center for MR Research, University of Illinois Hospital & Health Sciences System, Chicago, IL, United States, ²VasSol, Inc, River Forest, IL, United States, ³Neurosurgery, University of Illinois Hospital & Health Sciences System, Chicago, IL, United States, ⁴Bioengineering, University of Illinois at Chicago, Chicago, IL, United States, ⁵Neurosurgery, University of Illinois at Chicago, Chicago, IL, United States, ⁶Rheumatology, University of Illinois Hospital & Health Sciences System, Chicago, IL, United States, ⁷Departments of Radiology, Neurosurgery and Bioengineering, University of Illinois Hospital & Health Sciences System, Chicago, IL, United States

Assessment of treatment efficacy of Raynaud's disease requires a non-invasive, reliable, and quantitative method to measure blood flow in digital arteries. The goal of this study is to develop and evaluate a phase-contrast (PC) MR technique to meet this need. A high resolution non-contrast-enhanced 3D angiogram was first obtained to survey all proper palmar digital arteries. Based on the 3D angiogram, a plane strictly normal to the artery of interest was selected using an automated algorithm to reduce measurement errors in flow quantification with a 2D PC sequence. The measurement error was further reduced by correcting for residual eddy current effects. With this approach, consistent flow measurement (< 12% intra-subject variation) was obtained from human subjects. This study paves the way for future applications on patients with Raynaud's disease.

Bruce S. Spottiswoode¹, Aurelien F. Stalder², Mehmet Gulsun³, and Michael Markl^4,5
1Cardiovascular MR R&D, Siemens Healthcare, Chicago, Illinois, United States, ²Magnetic Resonance, Imaging & Therapy, Healthcare Sector, Siemens AG, Erlangen, Germany, ³Siemens Corporation, Corporate Technology, Princeton, New Jersey, United States, ⁴Department of Radiology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States, ⁵Department of Biomedical Engineering, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States

Pulse wave velocity (PWV) has been shown to be a reliable surrogate marker for cardiovascular disease. In this work, we described a method for automatically estimating PWV from 4D flow data after manually prescribing only the start and end points of the vessel. High temporal resolution 4D and 2D phase contrast flow data of the thoracic aorta were acquired in 9 healthy volunteers. The PWV derived from 4D and 2D flow data were in agreement with each other and with the literature, and sub sampling to a more typical temporal resolution had the effect of reducing the PWV estimates.

Hung-Hsuan Wang¹, Wen-Yih Isaac Tseng², Hsi-Yu Yu³, and Hsu-Hsia Peng^1
1Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu City, Taiwan, ²Center for Optoelectronic Biomedicine, National Taiwan University Medical College, Taipei City, Taiwan, ³Department of Surgery, National Taiwan University Hospital, Taipei City, Taiwan

Pulmonary arterial hypertension (PAH) is a deadly disease with a high mortality rate of 20-40% within three years after identification of diagnosis. Previous studies have proposed that the condition of low shear stress (SS) can activate endothelial cells (ECs) to produce vasoconstrictor substances and to inhibit vasodilator substances and therefore may cause vasoconstriction. In our previous study, a number of hemodynamic parameters have been used to differentiate patients with PAH from normal group. In this study, we aim to compute indices of wall shear stress (WSS) and oscillatory shear index (OSI) to investigate differences between normal subjects and PAH patients.

Erica Chirico¹, Michael C. Langham², Erin K. Englund², Susan Schultz¹, Lifeng Zhang³, Sandy Sehgal¹, Emile R. Mohler³, and Felix W. Wehrli^2
1Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, United States, ²University of Pennsylvania, Philadelphia, Pennsylvania, United States, ³Medicine, Cardiovascular Division, Vascular Medicine Section, University of Pennsylvania, Philadelphia, Pennsylvania, United States

We evaluated an integrated MRI protocol that consists of three quantitative techniques against established ultrasound (US) measures: flow-mediated dilation (FMD) of brachial artery and intima-media thickness (IMT) of carotid arteries. MRI techniques included dynamic velocimetry and oximetry in femoral artery and vein, respectively, and regional quantification of pulse-wave velocity in the aortic arch, thoracoabdominal aorta and iliofemoral arteries. The subjects consisted of healthy young and old without a history of cardiovascular disease. Initial results indicate that age-related decline in vascular reactivity are characterized by both MRI and US.

Henrik Haraldsson^1,2, Michael Hope³, Gabriel Acevedo-Bolton^1,2, Elaine Tseng^1,2, Xiaodong Zhong⁴, and David A. Saloner^1,2
1University of California, San Francisco, San Francisco, California, United States, ²Veteran Affairs Medical Center, San Francisco, California, United States, ³University of California San Francisco, San Francisco, California, United States, ⁴MR R&D Collaborations, Siemens Healthcare, Atlanta, Georgia, United States

Mechanical properties of the aortic wall have been used to diagnose disease. Current non-invasive techniques for assessing aortic deformation are based on diameter changes, and are sensitive to through-plane motion of the aorta. We propose a new MRI approach that measures the regional stretch of the aortic wall itself using DENSE. The results show a clear difference between young volunteers and older patients, and then between these patients depending on whether the aorta is dilated or not. Regional differences in stretch could be seen in all groups, with increased stretch values towards the right-posterior quadrant of the aorta.

M.J. Negahdar¹, Mo Kadbi¹, JungWon Cha¹, Juan Cebral², and Amir A. Amini^1
1Electrical and Computer Engineering, University of Louisville, Louisville, Ky, United States, ²School of Computational Sciences, George Mason University, Fairfax, VA, United States

In this paper we develop a novel non-iterative approach to determination of hemodynamic pressures from phase-contrast MRI. 3D gradients of pressure obtained from Navier-Stokes equation are expanded into a series of orthogonal basis functions, and are subsequently projected onto an integrable subspace. When using the FFT, the approach involves application of three 3D FFT’s and one inverse FFT. The proposed method results in highly accurate relative pressures and significantly improves on CPU time when compared with the conventional iterative approach to pressure calculations. Validations have been performed using CFD simulations and in-vitro MRI studies of stenotic flows under constant flow.

Pablo Bächler^1,2, Gerard Crelier³, Lida Toro⁴, Myriam Ferreiro⁴, Marcelo Andia^1,2, Cristian Tejos^2,5, Pablo Irarrázabal^2,5, and Sergio Uribe^1,2
1Department of Radiology, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile, ²Biomedical Imaging Center, Pontificia Universidad Católica de Chile, Santiago, Chile, ³Institute for Biomedical Engineering, University and ETH, Zurich, Switzerland, ⁴Hospital Sótero del Río, Santiago, Chile, ⁵Department of Electrical Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile

When forward and backward flows are present in the same heart phase, underestimation of regurgitant flow fraction (RF) may occur if flow is quantified by the standard method of averaging flow volume. We propose to quantify forward and backward flow volumes per voxel in each heart phase, and then calculate RF. We applied this method in patients with repaired Tetrology of Fallot and found higher values of RF compared to the standard method. Since surgical management might be recommended for patients with high RF, the standard method could not detect patients who might benefit from surgical intervention.

Guilhem Jean Collier¹, Andy Swift¹, David Capener¹, David Kiely¹, and Jim M. Wild^1
1Department of Cardiovascular Science, The University of Sheffield, Sheffield, Yorkshire, United Kingdom

A 4D flow study was performed on a group of patients with pulmonary hypertension and healthy volunteers to assess the formation and existence of vortices in blood flow in the pulmonary artery. Contrary to the published data in the literature, our results show that vortices with back flow in the main pulmonary artery are present in a significant percentage of healthy subjects and that their relative period of existence is not a sensitive parameter for determining the degree of PH severity.

Bradley D. Allen¹, Alex J. Barker¹, Jeremy D. Collins¹, Lubna Choudhury², James C. Carr^1,2, Robert O. Bonow², and Michael Markl^1,3
1Department of Radiology, Northwestern University, Chicago, IL, United States, ²Department of Medicine-Cardiology, Northwestern University, Chicago, IL, United States, ³Department of Biomedical Engineering, Northwestern University, Chicago, IL, United States

The aim of this study was to demonstrate the feasibility of 4D flow MRI for the comprehensive characterization of flow patterns and quantification of hemodynamic parameters in patients with obstructive hypertrophic cardiomyopathy (HCM). The results show that pressure gradients based on peak velocities in the left-ventricular outflow tract (LVOT) using 4D flow volumetric analysis are in agreement with those obtained via echocardiography. Flow pattern analysis demonstrates increasing helicity in the ascending aorta that correlates with myocardial septal thickness. LVOT volumetric velocity analysis provides gradient quantification at any time-point in the cardiac cycle.

Li Jiang¹, Huijun Chen¹, Xu Han², Zhensen Chen¹, Rui Li¹, Le He¹, Chun Yuan^1,3, and Xihai Zhao^1
1Center for Biomedical Imaging Research & Department of Biomedical Engineering, Tsinghua University, Beijing, China, ²Department of Radiology, PLA General Hospital, Beijing, China, ³Department of Radiology, University of Washington, Seattle, WA, United States

Wall compliance, as a systemic biomechanical characteristic of degeneration of vessel wall, has been demonstrated to be associated with atherosclerosis disease risk. In this study, we investigated the correlation of wall compliance between carotid artery and abdominal aorta and its role in assessment of severity of carotid atherosclerosis. We found that compliance of carotid artery differed from abdominal aorta and was associated with abdominal aorta compliance as well as carotid atherosclerotic plaque burden. Our findings indicate that arterial compliance in one vascular bed might be an indicator for other vascular biomechanical characteristics and severity of atherosclerotic disease.

Zachary Rodgers¹, Lohith Kini¹, Varsha Jain¹, Michael C. Langham¹, Jeremy F. Magland¹, and Felix W. Wehrli^1
1Radiology, University of Pennsylvania, Philadelphia, PA, United States

A dual-echo phase contrast pulse sequence with BRISK k-space sampling was used to quantify intravascular blood flow and oxygen saturation (%HbO₂) simultaneously at 2 s temporal resolution. BRISK sampling was shown to have improved motion sensitivity compared to keyhole as well as improved ability to resolve changes in blood flow and %HbO₂ during dynamic physiologic paradigms in both the cerebral and peripheral veins. Applications of this pulse sequence include high temporal resolution quantification of cerebral metabolism and evaluation of peripheral artery disease in response to post-occlusion reactive hyperemia in the leg.

Davi Marco Lyra-Leite^1,2, Krishna S. Nayak¹, and Joao L. A. Carvalho^2
1Department of Electrical Engineering, University of Southern California, Los Angeles, California, United States, ²Departamento de Engenharia Eletrica, University of Brasilia, Brasilia, Distrito Federal, Brazil

We retrospectively applied 3D SPIRiT to the reconstruction of spatially and temporally-undersampled spiral Fourier velocity encoding (FVE) data, and compared this reconstruction with sum-of-squares, and with 2D image-domain SPIRiT without temporal acceleration. Using a single calibration step and 4-fold acceleration, 3D SPIRiT presented FVE time-velocity distributions with higher SER than the other approaches. This reconstruction is also twice as fast as the 2D image-domain SPIRiT reconstruction.

Zachary Rodgers¹, Michael C. Langham¹, Jeremy F. Magland¹, John A. Detre², and Felix W. Wehrli^1
1Radiology, University of Pennsylvania, Philadelphia, PA, United States, ²Neurology, University of Pennsylvania, Philadelphia, PA, United States

A non-gated method for quantification of cerebrovascular compliance (CVC) – the change in volume (ΔV) divided by change in pressure (ΔP) of brain microvasculature over the cardiac cycle – is presented. Dual-slice interleaved velocity encoded projections provide simultaneous measurement of cerebral inflow and outflow waveforms continuously at 30 ms resolution for quantification of ΔV. Projection-based CVC produced similar waveform shapes and ΔV values compared to retrospectively gated PC-MRI in about 1/10th the scan time and without gating, greatly reducing potential errors due to temporal averaging. The method could be applied to better understand the vascular contribution to diseases such as Alzheimer’s.

Zachary Rodgers¹, Erin K. Englund¹, Michael C. Langham¹, Jeremy F. Magland¹, and Felix Wehrli^1
1Radiology, University of Pennsylvania, Philadelphia, PA, United States

Carotid pulse wave velocity (cPWV) was quantified by combining a dual-slice excitation phase-modulated sinc pulse with velocity-encoded projections to resolve flow waveforms in the inferior and superior carotid artery at 5 ms temporal resolution. This approach does not require gating and can quantify cPWV in just seconds. cPWV was measured in three young healthy males four times each. Overall mean (SD) cPWV and path length were 6.2 (1.9) m/s and 12.4 (2.2) cm respectively. Future work will focus on improving waveform post-processing and determining the utility of cPWV as an early marker of vascular changes leading to carotid atherosclerosis.

Michael Loecher¹, Claudio Santelli^2,3, Oliver Wieben^1,4, and Sebastian Kozerke^2,3
1Medical Physics, University of Wisconsin Madison, Madison, Wisconsin, United States, ²Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland, ³Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom, ⁴Radiology, University of Wisconsin Madison, Madison, Wisconsin, United States

A phase divergence penalty is proposed to improve velocity vector field reconstructions from undersampled 3D phase-contrast flow measurements. The method referred to as L1-SPIRiTphase is tested using a digital flow phantom and data acquired in the aortic arch in-vivo. Significant improvements in reconstruction accuracy of 4-fold undersampled data are demonstrated when compared to conventional L1-SPIRiT reconstructions.

Christopher J. François¹, Alejandro Roldán-Alzate¹, Andrew L. Wentland¹, Heidi B. Kellihan², Naomi C. Chesler³, and Oliver Wieben^1,4
1Radiology, University of Wisconsin, Madison, WI, United States, ²Veterinary Medicine, University of Wisconsin, Madison, WI, United States, ³Biomedical Engineering, University of Wisconsin, Madison, WI, United States, ⁴Medical Physics, University of Wisconsin, Madison, WI, United States

4D flow-sensitive MRI was used to calculate pulmonary artery pulse wave velocity (PWV) in a canine model of acute thromboembolic pulmonary arterial hypertension (PAH). PWV significantly increased with PAH and was strongly correlated with mean pulmonary arterial pressure.

Ramkumar Krishnamurthy¹, Amol Pednekar², Jouke Smink³, Benjamin Cheong⁴, and Raja Muthupillai^4
1Rice University, Houston, Texas, United States, ²Philips Health Care, Houston, Texas, United States, ³Philips Health Care, Best, Texas, Netherlands, ⁴St. Luke's Episcopal Hospital, Houston, Texas, United States

A novel arrhythmia insensitive inversion recovery (AIIR) algorithm for myocardial viability imaging is presented. This algorithm can track the magnetization regrowth of tissue of interest and prospectively calculate the inversion time required to minimize artifacts arising due to variation in the normal heart sinus rhythm. Benefits of this algorithm can be felt especially in following scenarios: 1) Limited patient breath-holding capacity, 2) Severe Arrhythmias, 3) Longer duration Respiratory motion compensated scans (3D and high spatial resolution) that encounter more RR intervals per acquisition. Phantom validation and patient results demonstrate the superiority of the AIIR algorithm.

Sebastian Weingärtner^1,2, Mehmet Akçakaya¹, Kraig V. Kissinger¹, Warren J. Manning¹, and Reza Nezafat^1
1Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, United States, ²Computer Assisted Clinical Medicine, University Medical Center Mannheim, Heidelberg University, Mannheim, Germany

We propose a novel sequence for pre-contrast 2D myocardial T1 mapping during breath holds. Multiple blocks of two single-shot images are acquired for the generation of T1 maps. Different heart-rate independent T1 weighted contrasts are created by interleaving saturation and inversion pulses in the imaging blocks. This allows neglecting rest periods and enables the generation of heart rate independent T1 maps of high homogeneity in the absence of a contrast agent.

Donnie Cameron¹, Ariane Fillmer², Andreas Hock², Thomas W. Redpath³, Michael P. Frenneaux³, Dana Dawson¹, and Anke Henning^2,4
1University of Aberdeen, Aberdeen, United Kingdom, ²Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland, ³The University of Aberdeen, Aberdeen, United Kingdom, ⁴Max Planck Institute of Biological Cybernetics, Tübingen, Germany

Cardiac 1H MRS can be used assess myocardial lipid content and to investigate pathophysiologies, but spectral quality is severely limited by cardiac and respiratory motion, as well as static field inhomogeneities, which are especially challenging at higher field strengths. In this work, ECG-triggering, navigator-gating, frequency alignment and phase correction are combined, for the first time, with a metabolite-cycled 1H cardiac MRS method and an improved ‘Localised B0 Shimming Tool’ to produce superlative motion compensation at 3T. Resulting spectra, acquired in 5 volunteers, show superior quality to others reported at this field strength (e.g. CH2 lipid SNR=28, FWHM=25, CRLB=1.8%).

Bastiaan J. van Nierop¹, Jules L. Nelissen¹, Noortje A.M. Bax², Abdallah G. Motaal¹, Larry de Graaf¹, Klaas Nicolay¹, and Gustav J. Strijkers^1
1Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Noord Brabant, Netherlands, ²Soft Tissue Biomechanics and Engineering, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Noord Brabant, Netherlands

Fibrosis is an important hallmark of various cardiac pathologies. Noninvasive imaging techniques for the assessment of fibrosis are highly desired. Here, we report on in vivo 3D ultra short TE (UTE) MRI for the assessment of diffuse myocardial fibrosis in mouse pressure overload-induced hypertrophy. The in vivo signal change from short-TE to long-TE images was larger in hypertrophic as compared to control hearts. Ex vivo measurements revealed that this can be attributed to T2* changes as a consequence of the presence of diffuse fibrosis. Thus, UTE MRI could provide a noninvasive readout for diffuse fibrosis in relation to myocardial hypertrophy.

Mahon L. Maguire¹, Kiterie M. Faller¹, Debra Medway¹, Victoria Thornton¹, Craig A. Lygate¹, Andrew M. Blamire², Stefan Neubauer¹, and Jurgen E. Schneider^1
1Dept. Cardiovascular Medicine, University of Oxford, Oxford, United Kingdom, ²Newcastle Magnetic Resonance Centre, Newcastle University, Newcastle upon Tyne, United Kingdom

Measurement of myocardial sodium levels can provide insight into electrophysiological disruption and tissue injury. We present absolute quantitation of tissue sodium concentrations in vivo in control and acutely infarcted mouse hearts. The combination of acquisition weighted chemical shift imaging (CSI) and an actively decoupled volume transmit resonator with small surface receive coil allowed the acquisition of ²³Na images with high spatial resolution. B1 corrections were applied to compensate inhomogeneities in both transmit and receive coil profiles. Acute myocardial infarction resulted in elevated tissue sodium in infarcted myocardium relative to both remote myocardium and myocardium in control mice.

Octavia Bane^1,2, Daniel C. Lee³, Brandon C. Benefield³, Kathleen R. Harris¹, Neil R. Chatterjee^2,3, James C. Carr¹, and Timothy J. Carroll^1,2
1Radiology, Northwestern University, Chicago, IL, United States, ²Biomedical Engineering, Northwestern University, Evanston, IL, United States, ³Medicine, Northwestern University, Chicago, IL, United States

We sought to determine the compartmentalization of the blood pool agent gadofosveset and the effect of its transient binding to albumin on the quantification of steady-state fractional myocardial blood volume (fMBV). Simulations of the transient binding of gadofosveset to albumin, and fMBV measurements in healthy volunteers with gadofosveset and in a canine subject with a USPIO contrast agent were performed. The distribution of the volunteer data indicates that a three-compartment model, with slow exchange of gadofosveset and water protons between the vascular and interstitial compartments, and fast water exchange between the interstitium and the myocytes, is appropriate.

Kilian Weiss¹, Severin Summermatter¹, Christian T. Stoeck¹, and Sebastian Kozerke^1
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland

In cardiac magnetic resonance spectroscopy signals are acquired using a combination of ECG triggering and navigator gating to compensate for cardiac and respiratory motion. While the effects and compensation of motion induced by respiration has been studied in detail only little work has been done to study and compensate the impact of cardiac bulk motion on signal-to-noise ratio performance so far. In the current work the sensitivity of point-resolved cardiac magnetic resonance spectroscopy to cardiac motion is examined using a numerical motion model and in-vivo measurements. It is demonstrated that the signal-to-noise ratio is strongly dependent on sequence timing relative to cardiac motion. An optimized sequence design employing reduced FID spoiling is proposed to limit sensitivity to motion. Using the proposed sequence Significant gains in SNR and improved inter-scan reproducibility are achieved, facilitating the integration of cardiac spectroscopy in clinical scan protocols by maximizing the achieved SNR per time unit and increasing reproducibility and reliability of myocardial triglyceride quantification.

Guido Buonincontri¹, Carmen Methner², Thomas Krieg², T. Adrian Carpenter¹, and Stephen J. Sawiak^1,3
1Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, United Kingdom, ²Department of Medicine, University of Cambridge, Cambridge, United Kingdom, ³Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, United Kingdom

Late gadolinium enhancement is a remarkably accurate way of assessing tissue viability after myocardial infarction. Performing this technique in mice is useful for translational drug studies carried out longitudinally in order to monitor adverse remodeling. In mice, high cardiac rate and small size mean that standard TI-optimised inversion recovery is not as efficient as in humans. To achieve LGE imaging efficiently we propose and validate a multi-slice method with an optimised acquisition scheme. Our method achieves excellent hyperenhancement and CNR and does not require TI optimization.

Yu-Wei Tang¹, Tzu-Chao Chuang², Hsiao-Wen Chung¹, and Teng-Ti Huang^3
1Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan, ²Department of Electrical Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan, ³Department of Electrical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan

In this study, we proposed a fast pixel-wised T1 mapping method by using the first three images obtained in MOLLI acquisition. The three-point T1 mapping algorithm is based on recently reported a 3D whole brain T1 mapping technique. High correlation of T1 measurements between our method and MOLLI was demonstrated. For patients could not perform long breath-hold successfully, the proposed fast T1 mapping method would offered an appropriate option.

Daniel Gensler¹, Philipp Mörchel¹, Florian Fidler¹, Oliver Ritter², Mark E. Ladd³, Harald H. Quick⁴, Wolfgang Rudolf Bauer², Peter M. Jakob^1,5, and Peter Nordbeck^2
1Research Center for Magnetic Resonance Bavaria e.V., Würzburg, Bavaria, Germany, ²Department of Internal Medicine I, University Hospital Würzburg, Würzburg, Bavaria, Germany, ³Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen, Germany, ⁴Institute of Medical Physics, University Erlangen-Nürnberg, Erlangen, Bavaria, Germany, ⁵Experimental Physics 5, Iniversity of Würzburg, Würzburg, Bavaria, Germany

Cardiac T1-mapping is becoming an increasingly important imaging technique, which establishes new non-invasive diagnostic possibilities. Currently common T1-mapping methods are known to be highly heart rate dependent and T1 is underestimated. Furthermore, these methods are quite slow, requiring breath holds up to 18s and more. Therefore, this work presents a fast cardiac T1 quantification technique, which can generate very accurate T1-maps in very short time (6s). This was realized by using an ECG-triggered radial single-shot IR sequence (TRASSI) with a special fitting algorithm. Herewith, accurate, high-resolution T1-maps without motion artifacts and without any heart rate dependency can be acquired.

Ina Vernikouskaya^1,2, Peter Bernhardt¹, Wolfgang Rottbauer¹, and Volker Rasche^1,2
1Internal Medicine II, University Hospital of Ulm, Ulm, Baden-Wuerttemberg, Germany, ²Small Animal MRI, University of Ulm, Ulm, Baden-Wuerttemberg, Germany

Quantitative T₂ mapping is required for the characterization of myocardial tissue. The superior performance of the black-blood preparation compared to the bright-blood data for myocardial T₂^* measurements in iron-overloaded thalassemia has been reported. Therefore the aim of this work was to compare the performance of the monoexponential and offset mapping algorithms for T₂ quantification based on T₂-prepared steady-state free precession imaging technique with and without black-blood preparation. The preliminary results obtained from 5 subjects showed that the offset model provide a more robust T₂ decay curve fitting for myocardial T₂ mapping compared to the simple monoexponential model in both bright- and black-blood data.

Yasuo Amano¹, Masaki Tachi¹, Mitsunobu Kitamura¹, Hitomi Tani¹, and Shinichiro Kumita^1
1Nippon Medical School, Tokyo, Tokyo, Japan

Asymmetric septal hypertrophic cardiomyopathy with a preserved ejection fraction is the most common type of hypertrophic cardiomyopathy. In this condition, the mass % of myocardial scarring on LGE MRI is the significant parameter related to ventricular tachyarrhythmia and the subsequent invasive treatments for it among clinical and MRI parameters. Quantification of the mass % of myocardial scarring is recommended to confirm the relationship between LGE MRI and ventricular tachyarrhythmia, which should be treated by invasive treatments, in asymmetric septal hypertrophic cardiomyopathy with a preserved ejection fraction.

Ariane Fillmer¹, Donnie Cameron², Thomas W. Redpath², Michael P. Frenneaux², Dana Dawson², and Anke Henning^1,3
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, ZH, Switzerland, ²University of Aberdeen, Aberdeen, United Kingdom, ³Max Planck Institut for Biological Cybernetics, Tübingen, Germany

MR spectroscopy in the myocardium is complicated, due to the presence of cardiac and respiratory motion, as well as the vicinity of the strong susceptibility boundaries to the lung and arteries. Therefore, excellent B0 shim quality is essential. Here we present an optimized B0 shimming approach by comparing projection based and image based B0 shim routines in combination with respiratory gating and ECG triggering at 3T.

Andreas Greiser¹, André Rudolph², Matthias Alexander Dieringer², Julius Traber², Evelyn Polzin², Edgar Mueller¹, and Jeanette Schulz-Menger^2
1Healthcare Sector, Siemens AG, Erlangen, Bavaria, Germany, ²Working Group Cardiac MR, Charité, ECRC Humboldt-University, Berlin and HELIOS Clinics, Berlin, Berlin, Germany

Suboptimal TI selection in late gadolinium enhancement (LGE) cardiac MRI can be overcome by a new robust, user-independent approach to TI optimization based on a fast T1-mapping protocol and automated segmentation. The T1 mapping allows a shorter breath-hold than the standard TI scout protocol. The T1-map-based TI times are in good agreement with the user-selected TI-scout-based values (266.4±40.5ms vs. 266.9±35.4 ms) but vary from the TI scout values (251.6±35.7 ms). T1-map-derived TI times match the user-defined values better than the objective TI scout values. The presented method provides a new option for standardization in clinical research and routine CMR.

feifei Qu¹, Ramkumar Krishnamurthy², Amol Pednekar³, Benjamin Y. Cheong⁴, Claudio Arena⁴, Pei-Herng Hor¹, and Raja Muthupillai^5
1Physics, University of Houston, Houston, TX, United States, ²BioEngineering, Rice University, Houston, TX, United States, ³Philips HealthCare, Houston, TX, United States, ⁴Radiology, St. Luke¡¯s Episcopal Hospital, Houston, TX, United States,⁵Radiology, St. Luke's Episcopal Hospital, Houston, TX, United States

The combination of SENSE, and ZOOM allowed us to reduce the total number of phase encoding steps without compromising spatial resolution, as well as the incorporation of variable refocusing flip angle readout to maintain the myocardial signal intensity during the readout, allows one to acquire DIR-BB prepared T1 weighed images of the heart within a reasonable breathhold of 5-7 s per slice. Our results show that myocardial to liver contrast can be improved by 50 %.

Dagmar Hartung¹, Katja Hueper², Marcel Gutberlet¹, Anne- Mieke Detlef³, Claire Weiss³, Anne Von Bohlen³, Refik Pul⁴, Ulrich Schweiger⁵, Helge Frieling³, Ralf Lichtinghagen⁶, Frank Wacker¹, and Kai G. Kahl^3
1Radiology, Medical School Hannover, Hannover, Germany, ²Radiology, Hannover Medical School, Hannover, Germany, ³Psychiatry, Medical School Hannover, Hannover, Germany, ⁴Neurology, Medical School Hannover, Hannover, Germany,⁵Psychiatry, University Medical Center Schleswig-Holstein, Lübeck, Germany, ⁶Clinical Chemistry, Medical School Hannover, Hannover, Germany

Major depressive disorder is associated with an increased risk for coronary artery disease. As epicardial adipose tissue (EAT), a metabolically active visceral fat depot, has been implicated in the pathogenesis of coronary artery disease, we hypothesize that EAT is increased in patients with major depression. Fat volumes were quantified by MRI and compared between groups. EAT was significantly elevated in patients with major depression and highest in a subgroup of patients with chronic depression. Therefore, increased EAT may contribute to the higher cardiovascular morbidity in depressed patients and particularly in the chronic form of this disease.

Sébastien Roujol¹, Tamer A. Basha¹, Mehmet Akçakaya¹, Murilo Foppa¹, Kraig V. Kissinger¹, Beth Goddu¹, Sophie J. Berg¹, Warren J. Manning^1,2, and Reza Nezafat^1
1Medecine, BIDMC / Harvard Medical School, Boston, MA, United States, ²Radiology, BIDMC / Harvard Medical School, Boston, MA, United States

2D Late gadolinium enhancement (LGE) MRI is commonly used for assessment of scar in the left ventricle. 3D LGE is an alternative approach where the entire LV is imaged in a single scan, allowing higher spatial resolution and better coverage. However, 3D scans are usually long, require free-breathing acquisitions and are respiratory gated using a navigator. Navigator gating will increase the scan time by 2-3 times. In this study, we sought to investigate the feasibility of an accelerated 3D LGE acquisition within one single prolonged breath hold using pre-oxygenation and hyperventilation.

Yasuo Amano¹, Masaki Tachi¹, Yoshio Matsumura¹, and Tetsuro Sekine^1
1Nippon Medical School, Tokyo, Tokyo, Japan

Myocardial and blood T1 values measured using Look-Locker CMR reflect myocardial fibrosis. However, the location of measuring the blood T1 value has not been confirmed because of concern about flow artifact, gadolinium distribution, or cardiac motion. We evaluated difference in the blood T1 value between the right and left ventricles (RV and LV) on 4-chamber contrast-enhanced Look-Locker CMR and assessed its relation with cardiac function. The 4-chamber Look-Locker CMR allows for the blood T1 value measurement after contrast both in the LV and RV, and the T1 value is not affected by valvular dysfunction, ejection fraction, and heart rate.

Yasuo Amano¹, Masaki Tachi¹, Hitomi Tani¹, Shinichiro Kumita¹, and Makoto Obara^2
1Nippon Medical School, Tokyo, Tokyo, Japan, ²Philips Healthcare Asia Pacific, Tokyo, Tokyo, Japan

Apical hypertrophic cardiomyopathy (APH) showed myocardial hypertrophy and scarring dominantly in the left ventricular apex. The mass percentage of myocardial scarring is associated with the decrease in the LV ejection fraction and traditional risk factors plus family history of hypertrophic cardiomyopathy in APH. Conversely, we do not have to quantify myocardial T1 value for the risk stratification of APH, because the T1 value did not differ between the apex and other non-hypertrophied myocardium and had no association with the risk factors.

Eissa Aguor¹, Cees van de Kolok¹, Pieter A.F.M Doevendans¹, Gustav J. Strijkers², and Fatih Arslan^1
1Cardilogy, UMC, Utrecht, Utrecht, Netherlands, ²Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands

Noninvasive techniques to characterize the myocardium during infarct development are essential to assess efficacy of novel therapeutics. We have recently shown that quantitative T2* mapping can provide additional information on infarct status and changes in the infarcted myocardium in relatively small murine infarctions after ischemia/reperfusion injury, In this study, we further explored quantitative changes in T2*in the myocardium of a mouse heart failure model induced by severe myocardial infarction. Quantitative T2*values decreased dynamically in the infarct. Interestingly, T2* in remote area also decreased significantly from baseline, most likely as a result of adverse ventricular remodeling of non-infarcted areas after MI.

Kelvin Chow¹, Joseph J. Pagano¹, and Richard B. Thompson^1
1Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada

The MOLLI sequence commonly used for myocardial T₁ quantification is known to have systematic errors dependent on T₁ and T₂ values, although the interaction of these effects is not well understood. We propose an intuitive model for predicting MOLLI errors based on the magnetization perturbation of the imaging readout (M_diff), incorporating the effects of tissue relaxation and other sequence parameters. Experiments in phantoms show highly variable MOLLI accuracy that is strongly correlated with M_diff, due to varying magnetization perturbation caused by different T₂/T₁ values. Common sequence parameter changes also alter MOLLI accuracy in a way predicted by the M_diff model.

Antoine Delmas¹, Marine Beaumont², and Jacques Felblinger^2
1Université de Rennes1, CESSON-SEVIGNE, Ille-et-Vilaine, France, Metropolitan, ²IADI laboratory, VANDOEUVRE-LES-NANCY, Meurthe et Moselle, France, Metropolitan

Reproducibility experimentation of a logarithmic-based method to achieve the T2 repetition time on the segmented left ventricle. This method is based on only 2 echo times and, compared to the traditional exponential method, it decreases acquisition, computing and segmentation time.

Osama Abdullah¹, Arnold David Gomez¹, Samer Merchant¹, Owen Stedham¹, Michael Heidinger², Steven Poelzing², and Edward Hsu^1
1Bioengineering, University of Utah, salt lake city, Utah, United States, ²Cardiovascular Research and Training Institute, University of Utah, salt lake, Utah, United States

MR diffusion measurements were investigated in an animal model of isolated perfused heart and analyzed as functions of myocardial perfusion, diffusion encoding b-value and myofiber orientation. Results indicate that perfusion accounts for 14% and 10% of the apparent diffusion coefficients observed at normal flow in directions parallel and perpendicular to the myofibers, respectively. The contributions of perfusion increase when only lower b-values and decrease when only higher b-values were used to measure diffusion. These findings have practical implications for the design and interpretation of in vivo cardiac diffusion and DTI experiments

Hélène Feliciano^1,2, Davide Piccini^3,4, Joost P. A. Kuijer⁵, and Matthias Stuber^1,2
1Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland, ²Center for Biomedical Imaging (CIBM), Lausanne, Switzerland, ³Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL) / Center for Biomedical Imaging (CIBM), Lausanne, Switzerland, ⁴Advanced Clinical Imaging Technology, Siemens Healthcare IM S AW, Lausanne, Switzerland, ⁵Dept. Physics and Medical Technology, ICaR-VU, VU University Medical Center, Amsterdam, Netherlands

In this work, slice following capabilities were added to a pre-existing CSPAMM bSSFP tagging sequence and tested on a 3T clinical scanner. Validation in static and moving phantoms plus SNR and tag-CNR comparisons was performed. Subsequently, and because of systolic base-to-apex long axis shortening in vivo, we tested the hypothesis that there exist significant differences in quantitative short axis strain and rotation measurements between slice-followed and non-slice-followed CSPAMM acquisitions.

Guido Buonincontri¹, Nigel I. Wood², Simon Puttick², Alexander O. Ward¹, T. Adrian Carpenter¹, Stephen J. Sawiak^1,3, and A Jennifer Morton^2
1Wolfson Brain Imaging Centre, University of Cambridge, Cambridge, United Kingdom, ²Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom, ³Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, United Kingdom

Recent studies have demonstrated cardiac pathology in mouse models of Huntington's disease. Here we show that R6/2 mice have specific and progressive right ventricular failure. This phenotype is evident at an advanced state of the disease, but can be seen much earlier performing a dobutamine stress test. In particular, the presence of this pathology can be unmasked by dobutamine at 10 weeks of age, before the mice show any other transgenic phenotype.

Haja-Sherief N Musthafa¹, Mikko Turunen^1,2, Svetlana Laidinen^1,2, Tiia Husso¹, Sanna Honkanen¹, Suvi Kuosmanen¹, Erhe Gao³, Hanne Hakkarainen¹, Seppo Ylä-Herttuala^1,2, and Timo Liimatainen^1
1A.I. Virtanen Institute For Molecular Sciences, Kuopio, Eastern Finland, Finland, ²Ark Therapeutics Ltd., Kuopio, Eastern Finland, Finland, ³Temple University, Philadelphia, PA, United States

Angiogenic growth factors are used to treat myocardial infarct by improving blood flow and therefore prevent left ventricular remodelling. In this study, we applied cine imaging to evaluate therapeutic effects of intramyocardial lentiviral delivery of promoter targeted shRNA that mediates epigenetic effects. A significant decrease in infarct size was found in shRNA treated mice from day 4 to day 14 after infarction compared to control group. The increased VEGF-A levels detected by using ELISA and histological findings support the MRI findings and suggest the method a potential way to decrease infarct size and may find clinical applications in the future.

Kieren Grant Hollingsworth¹, Kate Hallsworth², Christian Thoma², Djordje G. Jakovljevic², Guy A. MacGowan³, Quentin Anstee¹, Andrew M. Blamire¹, Roy Taylor¹, Chris P. Day¹, and Michael I. Trenell^2
1Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, Tyne and Wear, United Kingdom, ²MOVElab, Newcastle University, Newcastle upon Tyne, Tyne and Wear, United Kingdom, ³Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, Tyne and Wear, United Kingdom

Non-alcoholic fatty liver disease (NAFLD) is associated with a twofold greater risk of developing cardiovascular disease than those witout. Little is known about the early cardiac alterations in NAFLD, limiting our ability to identify therapeutic strategies. This study aimed to define the effect of NAFLD on cardiac morphology, function and metabolism in a representative group of 19 subjects using MRI imaging, cardiac tagging and phosphorus spectroscopy. NAFLD patients had significantly thicker LV walls, with reduced longitudinal shortening. Peak torsion was unaltered but peak strain at the endocardial wall was increased. PCr/ATP ratio was not reduced, unlike the previous young male study.

Fabian Hezel¹, Peter Kellman², Lukas Winter¹, Oliver Kraus¹, Katharina Fuchs¹, and Thoralf Niendorf^1,3
1Berlin Ultrahigh Field Facility (B.U.F.F.), Max-Delbrueck Center for Molecular Medicine, Berlin, Germany, ²Medical Imaging Section, National Institutes of Health / NHLBI, Bethesda, Maryland, United States, ³Cardiovascular Magnetic Resonance, Experimental and Clinical Research Center, Berlin, Germany

This abstract shows in vivo SSFP CINE images of the human heart acquired at 7.0T. A rather uniform B1+-excitation of the region of interest was achieved by a ring of eight radiative bowtie transceiver elements. B1+-shimming in multiple feeding transmit channel mode and B0-shimming in single feeding transmit channel mode enabled us to acquire anatomical images with high resolution, SNR and CNR.

Kieren Grant Hollingsworth¹, Matthew G.D. Bates², Jane H. Newman³, Djordje G. Jakovljevic³, Andrew M. Blamire¹, Guy A. MacGowan⁴, Bernard D. Keavney⁴, Patrick F. Chinnery⁴, Douglass M. Turnbull², Robert W. Taylor², Michael I. Trenell³, and Grainne S. Gorman^3
1Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, Tyne and Wear, United Kingdom, ²Mitochondrial Research Group, Newcastle University, Newcastle upon Tyne, Tyne and Wear, United Kingdom, ³MOVElab, Newcastle University, Newcastle upon Tyne, Tyne and Wear, United Kingdom, ⁴Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, Tyne and Wear, United Kingdom

Cardiomyopathy is a cause of morbidity and mortality in patients with the m.3243A>G mutation. Early detection would enable the design of timely intervention. We hypothesised that abnormalities in left ventricular mechanics, bioenergetics and morphology would be detectable by MR research methods in m.3243A>G mutation carriers without known cardiac involvement. Comparing 22 such patients and their matched controls using cine imaging, cardiac tagging and phosphorus spectroscopy, we found significantly increased LV mass index (which correlated with urinary mutation load), increased peak cardiac torsion, reduced longitudinal shortening and a significant reduction in the ratio of cardiac PCr/ATP.

Yijen Lin Wu¹, Brent D. Barbe¹, Li Liu¹, T. Kevin Hitchens¹, and Chien Ho^1,2
1Pittsburgh NMR Center for Biomedical Research, Carnegie Mellon University, Pittsburgh, PA, United States, ²Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, United States

Although timely restoration of coronary blood flow has greatly improved acute mortality after acute myocardial infarction (MI), the long-term prognosis and post-MI heart failure remain poor, because ischemic reperfusion injury (IRI) triggers inflammation, resulting in greater tissue damage and remodeling. We explored the potential protective effects of the FDA-approved Intralipid on the hearts after IRI. The in-situ inflammation of the heart is monitored with cellular MRI, whereas outcomes of the Intralipid treatment are evaluated with multi-parameter integrated cardiac MRI. Our results show that Intralipid can protect hearts against IRI.

Gavin D. Merrifield¹, Jim Mullin², Carl S. Tucker³, Martin A. Denvir³, and William M. Holmes^2
1School of Clinical Sciences and Community Health, University of Edinburgh, Edinburgh, Scotland, United Kingdom, ²Glasgow experimental MRI Centre, University of Glasgow, Glasgow, Scotland, United Kingdom, ³Cardiovascular Sciences, University of Edinburgh, Edinburgh, Scotland, United Kingdom

The zebrafish has emerged as an excellent model for cardiovascular research, with many researchers being attracted by the increasing availability of molecular, genetic and physiological research tools. However, unlike with mammalian models, live imaging of heart function remains challenging in the adult zebrafish1. Unlike embryos (<5day), the skin of adult zebrafish is non-transparent, i.e. pigmented and scaled, thereby precluding optical methods. We have explored the possibility of using MRI for in-vivo cardiac imaging of adult zebrafish, by implementing a retrospective self-gated cardiac sequence.

Yuchi Liu¹, Xunbai Mei¹, Martin W. Zhu², Saul Flores³, Parvin Hakimi⁴, Richard Hanson⁴, Michiko Watanabe³, and Xin Yu^1
1Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OHIO, United States, ²Hawken School, Gates Mills, OHIO, United States, ³Department of Pediatrics, Case Western Reserve University, Cleveland, OHIO, United States, ⁴Department of Biochemistry, Case Western Reserve University, Cleveland, OHIO, United States

This study aimed to analyze the cardiac structure and anatomy of physically energetic PEPCK-Cmus mice, and to evaluate the efficacy of using PEPCK mouse as an animal model of exercised-induced physiological hypertrophy. Multiphase displacement-encoding with stimulated-echo technique was used to obtain in vivo measurements of cardiac anatomy and to quantify two-dimensional left ventricular myocardial wall motion.

Gavin D. Merrifield¹, Nichola M. Brydges², Lynsey S. Hall³, Jim Mullin⁴, Lindsay Gallagher⁴, Romain Pizzi⁵, and William M. Holmes^4
1Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, Midlothian, United Kingdom, ²Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, United Kingdom, ³School of Molecular and Clinical Medicine, Royal Edinburgh Hospital, Edinburgh, United Kingdom, ⁴Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom, ⁵Zoological Medicine Ltd, Dunfermline, United Kingdom

To assess the potential of existing MRI scanner performance to evaluate novel model animal species cardiac MRI was performed on large spiders. The acquired images were used to extract the first direct in vivo measurements of cardiac function in this type of animal. Measurements revealed a previously unknown relationship between animal mass and cardiac ejection fraction.

Karl K. Vigen¹, Eric G. Schmuck², Nicholas S. Hendren², Jill M. Koch², Timothy A. Hacker², and Amish N. Raval^2
1Radiology, University of Wisconsin-Madison, Madison, WI, United States, ²Medicine, University of Wisconsin-Madison, Madison, WI, United States

Pressure-Volume (PV) Loop assessment and cardiac MRI each have an established place in the diagnosis of ventricular dysfunction. In this work, we compare the cardiac functional measurements estimated by both techniques, particularly stroke volume, in a swine model of chronic ischemic cardiomyopathy in the resting state.

Mohammed Suhail^1,2, Mark W. Wilson¹, Steven W. Hetts¹, Robert F. Mattrey³, and Maythem Saeed^1
1Department of Radiology, University of California San Francisco, San Francisco, CA, United States, ²School of Medicine, University of California San Diego, La Jolla, CA, United States, ³Department of Radiology, University of California San Diego, La Jolla, CA, United States

We aimed to quantify longitudinal and circumferential strain in the left and right ventricles in animals subjected to solely LAD microemboli or LAD occlusion/reperfusion with and without microemboli using cine and tagged MRI. This analysis shows that LAD occlusion/reperfusion with microemboli causes severe impairment in longitudinal and circumferential strain in the LV, while other interventions showed impairment in circumferential strain only. The interaction between right and left ventricles after ischemic interventions is clearly demonstrated by the compensatory increase in right ventricular free wall contraction.

Mohammed Suhail^1,2, Mark W. Wilson¹, Steven W. Hetts¹, Robert F. Mattrey³, and Maythem Saeed^1
1Department of Radiology, University of California San Francisco, San Francisco, CA, United States, ²School of Medicine, University of California San Diego, La Jolla, CA, United States, ³Department of Radiology, University of California San Diego, La Jolla, CA, United States

This MRI study was designed to compare phasic, peak strain and time to peak strain after acute myocardial infarction caused by LAD coronary microembolization and occlusion/reperfusion. The infarct size on delayed contrast enhanced MRI was significantly smaller in animals subjected to microembolization compared to LAD occlusion/reperfusion. Microemboli and LAD occlusion significantly decreased peak strain when compared to remote myocardium. However, the difference in peak strain between interventions was not significant. The pattern of myocardial infarct plays a role in ventricular synchronization. Furthermore, there is disproportion between infarction size and circumferential strain in animals subjected to microembolization and LAD occlusion/reperfusion.

Konrad Werys^1,2, Lukasz Blaszczyk^1,2, and Szymon Cygan^3
1Institute of Radioelectronics, Warsaw University of Technology, Warsaw, Poland, ²Cardiac Magnetic Resonance Unit, The Cardinal Stefan Wyszynski Institute of Cardiology, Warsaw, Poland, ³Institute of Metrology and Biomedical Engineering, Warsaw University of Technology, Warsaw, Poland

Effective diagnostic tools in cardiology are one of the key factors for successful treatment and full recovery. For an evaluation, a proper model of the human heart is essential. We have created a dynamic phantom of the left ventricle to use in ultrasonography and magnetic resonance imaging, which are the most popular methods in heart diagnosis. Our early studies show that its construction resembles the conditions present in the heart muscle. In the future this model will allow us to prepare and compare different algorithms for the analysis of mechanical parameters and will also be a great training tool for medical imaging personnel.

Peter Kellman¹, Hui Xue², and Michael Schacht Hansen^3
1NHLBI, NIH, Bethesda, MD, United States, ²Siemens Corporate Research, Princeton, NJ, United States, ³NHLBI, National Institutes of Health, Bethesda, MD, United States

Both accuracy and precision of T1-mapping are important for quantitative measurements and reliable detection of abnormal elevation of T1. Accuracy reflects the systematic or bias errors while precision reflects the random error due to noise. The accuracy and precision of several popular methods, including inversion recovery and saturation recovery schemes, are investigated in detail using a waveform level Bloch simulation to assess accuracy, and Monte-Carlo method of repeated trials to assess precision. Simulations are confirmed with phantom measurements.

Michelle Fitts^1,2, Elodie Breton³, Eugene G. Kholmovski^2,4, Derek J. Dosdall^2,5, Sathya Vijayakumar^2,4, Kyung P. Hong^1,2, Ravi Ranjan^2,5, Nassir F. Marrouche^2,5, Leon Axel⁶, and Daniel Kim^2,4
1Bioengineering, University of Utah, Salt Lake City, Utah, United States, ²CARMA Center, University of Utah, Salt Lake City, Utah, United States, ³ICube, Strasbourg University, Strasbourg, Alsace, France, ⁴UCAIR, Department of Radiology, University of Utah, Salt Lake City, Utah, United States, ⁵Internal Medicine, University of Utah, Salt Lake City, Utah, United States, ⁶Department of Radiology, New York University, New York, New York, United States

We present a cardiac T1 mapping pulse sequence based on saturation recovery, which is arrhythmia-insensitive and rapid (AIR) for assessment of diffuse fibrosis. We compared its performance against the conventional cardiac T1 mapping inversion recovery based method, MOLLI, which is sensitive to heart rate and rhythm conditions, using an IR fast spin-echo sequence for reference. In vitro studies demonstrated that T1 measurements made by AIR were more precise and accurate than MOLLI at different heart rate and rhythm conditions. More work is needed to validate diagnostic accuracy and precision in patients with tachycardia and/or arrhythmias.

Peter Kellman¹, Daniel A. Herzka², and Michael Schacht Hansen^3
1NHLBI, NIH, Bethesda, MD, United States, ²Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States, ³NHLBI, National Institutes of Health, Bethesda, MD, United States

Myocardial T1-mapping based on Look-Locker methods such as MOLLI rely on ideal inversion recovery. Adiabatic inversion pulses used to mitigate inhomogeneity of transmit field strength do not achieve perfect inversion as a result of transverse relaxation (T2) during the pulse. Imperfect inversion leads directly to a T2-dependent error in the estimate of T1. An improved adiabatic inversion pulse optimized for myocardial T1-mapping was designed and evaluated experimentally. Due to peak power constraints, a tan/tanh design was found to achieve the best inversion performance for a given design specification. Reduced dependence on T1 and T2 facilitate a calibrated correction of T1-estimates.

Rieko Ishimura¹, Kenichi Yokoyama¹, Toshiya Kariyasu¹, Toshiaki Nitatori¹, Shuhei Nitta², Taichirou Shiodera², Tomoyuki Takeguchi², and Shigehide Kuhara^3
1Department of Radiology, Faculty of Medicine, Kyorin University, Mitaka-shi, Tokyo, Japan, ²R&D Center, Toshiba Corporation, Kawasaki-shi, Japan, ³Toshiba Medical Systems, Otawara-shi, Tochigi, Japan

Cardiac MRI allows the detailed morphologic and functional assessment of right ventricle (RV). However, determining the suitable RV planes for RV evaluation requires complex procedures. We propose a new automatic slice-alignment method to simplify cardiac RV scan planning and evaluate this methods in patients with pulmonary arterial hypertension (PAH). This methods was performed successfully in all subjects, and slice alignment for the RV reference planes was performed quickly and accurately despite the variation in the cardiac shapes due to the RV enlargement. These results suggest that our methods is clinically useful for evaluation of RV in patients with PAH.

Valentina Taviani¹, Diego Hernando², Alejandro Munoz Del Rio¹, Ann Shimakawa³, Randi Drees⁴, Rebecca Johnson⁴, Karl K. Vigen¹, Scott B. Reeder^1,5, and Christopher J. Francois^2
1Radiology, University of Wisconsin, Madison, WI, United States, ²Radiology, University of Wisconsin-Madison, Madison, WI, United States, ³Global MR Applied Science Laboratory, GE Healthcare, Menlo Park, CA, United States, ⁴Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI, United States, ⁵Medical Physics, University of Wisconsin, Madison, WI, United States

Accurate measurement of the aortic root is important to plan interventions and evaluate aortic abnormalities. 3D chemical-shift-encoded MRI during free-breathing can provide high-resolution, fat-suppressed images of the whole heart that can be used to perform morphological measurements. In this work, we compare aortic root measurements performed using this MRI technique with reference values obtained from conventional cardiac CTA. Repeatability of aortic root measurements performed with 3D chemical-shift-encoded MRI is also evaluated in relation to repeatability of CTA-based measurements.

James William Goldfarb^1,2, Usama Hasan¹, Wenguo Zhao¹, and Jing Han^1
1Department of Research and Education, Saint Francis Hospital, Roslyn, NY, United States, ²Program in Biomedical Engineering, SUNY Stony Brook, Stony Brook, NY, United States

In patients with myocardial infarction, high-pass filtered (HPF) phase imaging was compared with quantitative resting myocardial perfusion and late gadolinium-enhanced (LGE) infarct imaging. Infarct to remote segmental upslope percent showed a similar reduction in resting perfusion with the presence of microvascular obstruction (MVO) and myocardial hemorrhage at all stages of myocardial infarction. Reduced segmental resting perfusion was a sensitive, but not specific indicator of MVO and intramyocardial hemorrhage. Susceptibly-weighted HPF-phase imaging represents a new quantitative, high quality method for the detection of myocardial hemorrhage and is associated with reduced resting perfusion and MVO.

Wyger M. Brink¹ and Andrew Webb^1
1Radiology, Leiden University Medical Center, Leiden, Netherlands, Zuid-Holland, Netherlands

High permittivity pads are shown to improve the transmit efficiency, B1 homogeneity and CNR in bSSFP imaging significantly, resolving RF related artifacts commonly encountered in functional cardiac imaging at 3T. The proposed solution is shown to outperform dual-transmit RF shimming.

Behzad Sharif¹, Rohan Dharmakumar¹, Reza Arsanjani², Louise EJ Thomson², Noel Bairey Merz², Daniel S. Berman², and Debiao Li^1
1Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, ²Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States

Combined assessment of wall motion from cine imaging and perfusion defects from first-pass perfusion imaging has been shown to have a high diagnostic performance for detection of acute ischemia. In this work, we demonstrate the feasibility and effectiveness of ungated cardiac-phase resolved (cine) first-pass imaging for concurrent imaging of myocardial wall motion and perfusion in an animal model with flow-limiting stenosis.

Hui Xue¹, Yu Ding², Christoph Guetter¹, Andrew E. Arai³, and Peter Kellman^3
1Siemens Corporate Research, Princeton, New Jersey, United States, ²Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, Ohio, United States, ³National Institutes of Health, National Heart, Lung and Blood Institute, Bethesda, Maryland, United States

To improve the quality of free-breathing myocardial perfusion imaging, we propose a novel reconstruction algorithm named as MOCO-SPIRiT which extends the SPIRiT reconstruction by incorporating non-rigid respiratory motion correction (MOCO). With motion correction, it is possible to employ spatial-temporal regularization for better image quality while retaining the dynamic information (i.e. preserve the fidelity of time intensity curves). In this way, the improved SNR may be used to support higher spatial resolution which is the key to minimize dark rim artifacts. Unlike k-t methods without MOCO that are susceptible to respiratory motion, the proposed method allows free-breathing. Both phantom and in-vivo tests show the new algorithm leads to higher SNR and lower artifacts, compared to TGRAPPA and L1SPIRiT.

Zhe Wang^1,2, Meral L. Reyhan^1,3, Abbas N. Moghaddam^1,4, J. Paul Finn⁵, and Daniel B. Ennis^2,5
1Department of Radiological Sciences, University of California, Los Angeles, CA, United States, ²Department of Bioengineering, University of California, Los Angeles, CA, United States, ³Biomedical Physics Interdepartmental Program, University of California, Los Angeles, CA, United States, ⁴Department of Biomedical Engineering, Amirkabir University of Technology(Tehran Polytechnic), Tehran, Iran, ⁵Department of Radiological Sciences, University of California Los Angeles, Los Angeles, CA, United States

Radial tagging matches the annular shape of the left ventricle (LV) in short axis images and has an advantage for measuring LV twist. Current LV twist measurement methods require manual contouring of the LV epicardial and endocardial boundaries, which increases the processing time. We demonstrate a method which utilizes the unique tagging contrast in complementary radial tagging (CRT) for fully automated LV contouring for the quantification of LV twist. Comparison of the LV twist measurements derived from manually and automated segmentation techniques shows excellent agreement (R=0.99) and no significant differences. Fully automated LV twist measurement can be achieved with CRT.

Verena Hoerr¹, Nina Nagelmann¹, Arno Nauerth², and Cornelius Faber^3
1University Hospital Muenster, Muenster, Germany, ²Bruker BioSpin MRI GmbH, Ettlingen, Germany, ³University Hospital Münster, Muenster, Germany

To minimize flow and susceptibility artifacts in cardiovascular magnetic resonance imaging (CMR), we have implemented a cardiac and respiratory self-gated cine ultra-short echo time (UTE) sequence. In comparison with a self-gated fast low angle shot (FLASH) sequence the UTE sequence was superior in terms of image quality and the observation of the cardiac valves. To further improve the observation of the moving valves, Reflection Point visualization was used highlighting valvular tissue. This novel visualization technique allowed for a clear observation of the movement of the four cardiac valves: aortic, mitral, pulmonary and tricuspidal valve, during the full cardiac cycle.

Francisco Contijoch¹, Walter R.T. Witschey¹, Jeremy McGarvey¹, Melissa Levack¹, Victor A. Ferrari¹, Julio Chirinos¹, Norihiro Kondo¹, Satoshi Takebayashi¹, Toru Shimaoka¹, Chikashi Aoki¹, Gerald A. Zsido¹, Joseph Gorman¹, Robert C. Gorman¹, and James J. Pilla^1
1University of Pennsylvania, Philadelphia, PA, United States

We validate here a real time (i.e. no cross-beat view sharing or temporal regularization) method using regional (a single tomographic slice) PV relations in an animal model across a range of normal and post-infarct ejection fractions (EF) and stroke volumes (SV) at intermediate heart rate (100 bpm). We further demonstrate for the first time that MRI can be used to characterize beatwise alterations in regional PV relations during an LV inflow occlusion (i.e. to reduce preload) to measure regional wall stiffness (end-systolic PV relation – ESPVR).

Sebastian Weingärtner^1,2, Mehmet Akçakaya¹, Warren J. Manning¹, and Reza Nezafat^1
1Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, United States, ²Computer Assisted Clinical Medicine, University Medical Center Mannheim, Heidelberg University, Mannheim, Germany

Late Gadolinium Enhancement and myocardial T1 mapping are methods with distinct advantages for evaluation of myocardial scar and fibrosis. Conventionally these are performed as two separate sequences. Also T1 mapping is commonly performed by acquiring multiple 2D single-shot images during one breath-hold per slice. We propose a novel sequence for combined free-breathing 3D LGE and 3D T1 mapping. This allows efficient imaging by reusing the LGE data for T1 mapping. Furthermore it provides improved spatial coverage, higher resolution and higher signal-to-noise ratio compared to 2D imaging.

Xiao Chen¹, Bhairav B. Mehta¹, Michael Salerno^2,3, and Frederick H. Epstein^1
1Biomedical Engineering, University of Virginia, Charlottesville, Virginia, United States, ²Medicine, University of Virginia, Charlottesville, Virginia, United States, ³Radiology, University of Virginia, Charlottesville, Virginia, United States

Modified Look-Locker Imaging (MOLLI) is routinely used for T1 mapping of the left ventricle. High resolution MOLLI requires fast imaging to remain free of artifacts due to cardiorespiratory motion. The combination of parallel imaging and compressed sensing (CS) has been used to accelerate cardiac cine and perfusion imaging but not MOLLI. We developed an algorithm that combines parallel SENSE and CS kt-Sparsity and Low Rank (kt-SLR) and applied it to accelerate MOLLI to achieve high resolution (1.2×1.2 mm²) T1 mapping using a standard breathhold clinical protocol (17 heartbeats).

Anthony G. Christodoulou¹, Yijen L. Wu², Qing Ye², T. Kevin Hitchens², Chien Ho², and Zhi-Pei Liang^1
1Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, United States, ²Pittsburgh NMR Center for Biomedical Research, Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, United States

This abstract presents a real-time imaging method for noninvasive detection of acute heart transplant rejection. Real-time imaging is achieved using sparse sampling of (k, t)-space by exploiting the partial separability and sparsity of the cardiac signals. Both anatomical (i.e. ejection fraction) and functional (i.e. first-pass myocardial perfusion) assessments were enabled in a single real-time scan instead of from separate gated and triggered scans. The method has been validated on rats with allograft heart and lung transplants, with reduction in cardiac function evident after multiple post-operational days.

Christopher A. Miller^1,2, Josephine H. Naish¹, Glyn Coutts³, David Clark⁴, Sha Zhou¹, Geoffrey J. M. Parker¹, and Matthias Schmitt^1,2
1Centre for Imaging Sciences & Biomedical Imaging Institute, University of Manchester, Manchester, United Kingdom, ²North West Heart Centre and The Transplant Centre, University Hospital of South Manchester, Manchester, United Kingdom, ³Christie Medical Physics and Engineering, The Christie Hospital, Manchester, United Kingdom, ⁴Alliance Medical Cardiac MRI Unit, Manchester, United Kingdom

This study provides whole-heart, histological validation of; 1. Dynamic-equilibrium cardiovascular magnetic resonance (DynEq-CMR), where myocardial extracellular volume (ECV) is quantified using hematocrit-adjusted myocardial and blood T1 values measured before and after gadolinium bolus; and 2. Isolated measurement of myocardial T1 at a fixed time-point following gadolinium bolus, used as an ECV surrogate.

Simon Gross¹, Benjamin E. Dietrich¹, Christoph Barmet^1,2, and Klaas P. Prüssmann^1
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland, ²Skope Magnetic Resonance Technologies, Zurich, Switzerland

Magnetic field fluctuations originating from the beating human heart can be measured using highly sensitive NMR field probes. The fluctuations are caused by changes in the local susceptibility distribution and are thus a measure for the bio-mechanical activity of the heart. Field fluctuations were measured with 15 NMR field probes simultaneously and with a temporal bandwidth of 200 Hz. ECG-signals were measured concurrently, and allowed to synchronize the field curves from different experiments. Like this, 210 positions on the chest were synchronized and will be of great value in identification and understanding of the underlying physiological mechanisms.

Sebastian Weingärtner^1,2, Mehmet Akçakaya¹, Warren J. Manning¹, and Reza Nezafat^1
1Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, United States, ²Computer Assisted Clinical Medicine, University Medical Center Mannheim, Heidelberg University, Mannheim, Germany

Myocardial T1 mapping is an emerging technique for improved evaluation of scar and fibrosis in the myocardium. Commonly 2D T1 mapping is performed with one breath hold per slice. We propose a novel free-breathing 3D T1 mapping sequence to benefit from the improved SNR and enable better spatial coverage and spatial resolution. The proposed scheme consists of multiple, interleaved inversion-recovery images. A joint prospective and retrospective navigator gating scheme is applied to compensate for respiratory motion. The acquired T1 maps were of improved homogeneity compared to MOLLI and free of motion artifacts induced by improper breath holds.

Katharina Fuchs¹, Fabian Hezel¹, Lukas Winter¹, Celal Oezerdem¹, Andreas Graessl¹, Matthias Alexander Dieringer^1,2, Oliver Kraus¹, and Thoralf Niendorf^1,3
1Berlin Ultrahigh Field Facility (B.U.F.F.), Max-Delbrueck Center for Molecular Medicine, Berlin, Germany, ²Working Group on Cardiovascular Magnetic Resonance, Experimental and Clinical Research Center, Berlin, Germany, ³Experimental and Clinical Research Center, a cooperation of the Charité Medical Faculty and the Max-Delbrueck Center for Molecular Medicine, Berlin, Germany

This study demonstrates the feasibility of cardiac fast spin echo (FSE) imaging at 7.0 T in healthy volunteers. For this purpose a novel 16 dipole element transmit/receive coil array is used. Our preliminary results show encouraging image quality reflecting subtle anatomical structures.

Jinnan Wang¹, Peter Börnert², Huijun Chen³, Gregory J. Wilson⁴, Chun Yuan⁴, and Jeffrey H. Maki^4
1Philips Research North America, Briarcliff Manor, NY, United States, ²Philips Research Laboratory, Hamburg, N.A., Germany, ³Tsinghua University, Beijing, Beijing, China, ⁴Radiology, University of Washington, Seattle, WA, United States

Phase Sensitive Inversion Recovery (PSIR) is now the method of choice for myocardial infarction (MI) detection and quantification. Compared to regular IR images, phase sensitive (PS) reconstructed images offer doubled dynamic range, improved contrast and higher flexibility in sequence design. One of the limitations of the PSIR technique is that it relies on a full size reference image to restore the polarity information, which makes the scan time much longer (essentially doubled) and more susceptible to motion artifacts. In this study, we propose the Referenceless Acquisition of Phase-sensitive Inversion-recovery with Decisive reconstruction (RAPID) that can reliably restore the polarity of the magnetization without relying on the reference image.

Yu-Sheng Tseng¹, Teng-Yi Huang¹, Yu-Wei Tang², and Yi-Ru Lin^3
1EE, NTUST, Taipei, Taiwan, ²EE, NTU, Taipei, Taiwan, ³EC, NTUST, Taipei, Taiwan

This study aimed to automatically identify the cardiac rest period using a rapid free-breathing (FB) calibration scanning procedure, and to determine the optimal trigger delay for cardiac imaging. The possibility of using a low-resolution FB method to rapidly acquire cine images was also evaluated. The real-time trigger delay calibration system was then used to perform T1-weighted short-axis imaging at the end of the cardiac systolic period. Combined with rapid FB calibration scanning, the real-time feedback system accurately adjusted the trigger delay for T1-weighted short-axis imaging.

Thomas Gaass¹, Guillaume Potdevin², Grzegorz Bauman^3,4, Peter Noël⁵, and Axel Haase^1
1Zentralinstitut für Medizintechnik, Technische Universität München, Garching, Germany, ²Department of Physics, Technische Universität München, Garching, Germany, ³Division of Medical Physics in Radiology, German Cancer Research Center, Heidelberg, Germany, ⁴Department of Medical Physics, University of Wisconsin, Madison, Wisconsin, United States,⁵Department of Diagnostic and Interventional Radiology, Technische Universität München, Munich, Germany

We introduce a novel reconstruction technique using a composite image histogram as constraint (CHiCA) in a non-linear reconstruction framework for the suppression of aliasing artifacts in sub-Nyquist-sampled MRI. The performance of CHiCA is successfully presented on a numerical simulation of a DCE MRI measurement and a simulated radial in vivo dynamic cardiac MR. Data acquisition was implemented as interleaved radial sampling with sliding window reconstruction to generate the composite image. The reconstruction of undersampled data by constraining the images’ histogram offers the possibility to significantly reduce measurement time, while effectively suppressing aliasing artifacts.

Glenn S. Slavin¹ and Jeffrey A. Stainsby^2
1GE Healthcare, Bethesda, MD, United States, ²GE Healthcare, Toronto, ON, Canada

Look-Locker-based cardiac T1 mapping methods such as MOLLI only measure “apparent” T1. Correction methods are therefore necessary to estimate true T1. SMART₁Map is a new technique that uses multiple single-point measurements in conjunction with long recovery times and real-time cardiac cycle timing to directly measure true T1, without the need for correction. This work compared the accuracy of SMART₁Map and MOLLI against IR spin-echo in phantom experiments under several imaging conditions. Whereas MOLLI showed significant dependence on T1, heart rate, and data acquisition window duration, SMART₁Map was insensitive to these parameters and yielded consistently accurate T1 measurements in all cases.

Simone Coppo^1,2, Davide Piccini^3,4, Jerome Chaptinel^1,2, Gabriele Bonanno^1,2, and Matthias Stuber^1,2
1Departiment of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland, ²Center for Biomedical Imaging (CIBM), Lausanne, Switzerland,³Advanced Clinical Imaging Technology, Siemens Healthcare IM S AW, Lausanne, Switzerland, ⁴University Hospital (CHUV) and University of Lausanne (UNIL) / Center for Biomedical Imaging (CIBM), Lausanne, Switzerland

Non-ECG triggered self-navigated radial 3D multiphase whole heart imaging with isotropic spatial resolution for coronary imaging has successfully been implemented and tested in three volunteers for the first time. Respiratory self-navigation without the need for ECG triggering improves ease-of-use while the acquisition time is well defined and independent on respiratory patterns and heart rate. Moreover, the isotropic spatial resolution together with the multiphase acquisition enables multi planar reformatting in any user selected plane and orientation while the cine frame with the best depiction of a given coronary segment can freely be selected.

Venkat Ramanan¹, Nilesh R. Ghugre¹, Charles H. Cunningham¹, Jeffrey A. Stainsby², Kim A. Connelly^1,3, Alex Leber⁴, and Graham A. Wright^1
1Imaging Research, Sunnybrook Research Institute, Toronto, Ontario, Canada, ²Applied Sciences Lab, GE Healthcare, Toronto, Ontario, Canada, ³Division of Cardiology, St Michael's Hospital, Toronto, Ontario, Canada, ⁴Division of Cardiology, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada

MOLLI is currently the favoured method for myocardial T1 mapping. It uses a 3-parameter exponential fitting which was originally derived only gradient-echo(FLASH) sequences. It also underestimates T1 for longer T1 values at higher heart-rates. Here we propose an alternative fitting method, Relaxometry Using Sequence SimuLation (RUSSL), based on Bloch-simulation of the whole sequence. In phantom studies, it seems to improve the heart dependency of MOLLI. It also provides support for the validity of the exponential fit used by MOLLI. In volunteers, the T1-maps were found to be very similar to MOLLI. Besides T1, the fit also provides T2 and M0; however T2 values were of limited accuracy.

Christopher Nguyen^1,2, Zhaoyang Fan¹, Behzad Sharif¹, Rohan Dharmakumar¹, James Min¹, Daniel S. Berman¹, and Debiao Li^1,2
1Biomedical Imaging Research Institute, Cedars Sinai Medical Center, Los Angeles, CA, United States, ²Bioengineering, University of California, Los Angeles, Los Angeles, CA, United States

Cardiac diffusion MRI has the potential to identify acute myocardial ischemia and assess the chronic change of myofiber orientation after a myocardial infarction. Cardiac motion and SNR limitations have been the primary challenges for the application of the technique in vivo. We propose a novel application of diffusion-prepared balanced steady-state free precession to include second order motion compensation and navigator-based free breathing. This not only allows for sufficiently high b-values, but also takes advantage of the higher SNR efficiency and image quality of bSSFP. ADC values acquired from the 11 volunteers are consistent with prior in vivo human cardiac diffusion studies.

Tomoe Barr¹, Chuan Huang^2,3, Ali Bilgin^4,5, Aiden Abidov^3,6, and Maria I. Altbach^3
1Biomedical Engineering, The University of Arizona, Tucson, AZ, United States, ²Center for Advanced Radiological Sciences, Massachusetts General Hospital, Boston, MA, United States, ³Medical Imaging, The University of Arizona, Tucson, AZ, United States, ⁴Biomedical Engineering, University of Arizona, Tucson, AZ, United States, ⁵Electrical and Computer Engineering, The University of Arizona, Tucson, AZ, United States, ⁶Medicine, The University of Arizona, Tucson, AZ, United States

In cardiac MR T2-weighted imaging or T2 mapping can be used for the evaluation of pathologies such as inflammation. Fast spin echo (FSE) methods allow for fast T2 mapping without compromising spatial or temporal resolution. A drawback of using an FSE acquisition is that indirect echoes (eg. stimulated echoes) affect T2 estimation. In this work we present a double inversion radial FSE (DIR-RADFSE) technique combined with a novel model-based reconstruction algorithm (CURLIE) for T2 mapping of the heart with compensation for indirect echoes. The method allows for T2 mapping from undersampled radial FSE data (data acquired in a breath hold) without T2 biases due to indirect echoes.

Fabian Kording¹, Bjoern Schoennagel¹, Chressen K. Much¹, Friedrich Ueberle², Hendrik Kooijman³, Jin Yamamura¹, Gerhard Adam¹, and Ulrike Wedegaertner^2
1Department of Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany, Germany, ²Fakulty of Life Sciences, University of Appljed Sciences Hamburg, Hamburg, Germany, Germany, ³Philips Medical Systems, Hamburg, Germany, Germany

In this study the feasibility of a novel Doppler-ultrasound device to trigger the heart frequency in cardiac MRI was assessed and compared to conventional ECG triggering. A commercially available ultrasound transducer was modified and the timing of the generated trigger signal was adapted to the physiologic time delay between the ultrasound signal and the electrocardiogram of the human heart to ensure the acquisition of a complete cardiac cycle. There was no difference between both methods in the evaluation of anatomical structures and functional information. The MR compatible Doppler-ultrasound device might be faster and easier in the application compared to ECG.

Scott K. Nagle^1,2, Laura C. Bell^3,4, Mark L. Schiebler^1,4, Christopher J. Francois^4,5, James H. Holmes⁶, Sean B. Fain^1,2, and Kang Wang^6
1Radiology, University of Wisconsin, Madison, WI, United States, ²Medical Physics, University of Wisconsin, Madison, WI, United States, ³Medical Physics, University of Wisconsin-Madison, Madison, WI, United States, ⁴United States, ⁵Radiology, University of Wisconsin-Madison, Madison, WI, United States, ⁶Global Applied Science Laboratory, GE Healthcare, Madison, WI, United States

Quantitative contrast-enhanced pulmonary perfusion MRI has been limited by the need for high temporal-spatial resolution, full-lung coverage, and the need to scan within a reasonable length breath-hold. The purpose of this work was to compare the performance of 3 different Cartesian under-sampling methods in combination with 2 alternative reconstruction methods to perform whole-chest, time-resolved pulmonary perfusion MRI with isotropic 4mm resolution and 0.5-1s temporal resolution. Qualitative assessment of image quality at peak parenchymal enhancement was comparable. However, quantitative assessment of the contrast enhancement curves showed higher maximum values, steeper up-slopes, and shorter rise-times using HYCR rather than view-sharing reconstruction.

Regine Schmidt¹, Dirk Graafen¹, Stefan Weber¹, and Laura Maria Schreiber^1
1Department of Radiology, Johannes Gutenberg University Medical Center, Mainz, Germany

The dispersion of a contrast agent bolus at myocardial perfusion MRI was simulated for a coronary bifurcation with stenosis in one branching vessel using the computational fluid dynamics (CFD) approach. Two sets of simulations for different outflow conditions through the stenotic branch were performed with four simulations for each set (rest and stress, pulsatile and constant velocity). We found a systematic underestimation of myocardial blood flow (MBF) up to -16.1% for pulsatile flow and an overestimation of the myocardial perfusion reserve (MPR) up to 7.5%.

Henrik Lauridsen¹, Asger Andersen², Michael Pedersen¹, and Steffen Ringgaard^1
1MR Research Centre, Aarhus University, Aarhus N, Denmark, ²The Department of Cardiological Medicine B, Aarhus University, Aarhus N, Denmark

Tissue regenerative potential in humans and mammalian animal model is limited. As opposed to this amphibian animal models such as the Mexican axolotl (Ambystoma mexicanum) are champions of regeneration and are, i.a., able to regenerate both complete limbs and myocardium after infarction. To measure the functional recovery of the regenerating axolotl heart in vivo, ECG-gated cardiac MRI was not possible due to a weak ECG signal in this amphibian, hence a self-gated semiautomatic cardiac MRI technique was developed. We suggest that this method should be considered when performing cardiac MRI on small animal models and encountering difficulties with traditional ECG-gating.

Shigehide Kuhara¹, Shuhei Nitta², Taichiro Shiodera², Tomoyuki Takeguchi², Kenichi Yokoyama³, Rieko Ishimura³, and Toshiaki Nitatori^3
1MRI Systems Development Department, Toshiba Medical Systems Corporation, Otawara-shi, Tochigi, Japan, ²Corporate Research & Development Center, Toshiba Corporation, Kawasaki-shi, Kanagawa, Japan, ³Department of Radiology, Faculty of Medicine, Kyorin University, Mitaka-shi, Tokyo, Japan

Manual setting of the motion probe for whole-heart MR imaging with motion correction to obtain high-resolution images during free breathing remains a time-consuming task, even for expert technologists. We propose an automatic motion probe setting method employing an atlas-based segmentation technique to detect the heart region and the position of the top of the right hemidiaphragm at the same time for motion probe setting. Clinical evaluation showed that the position of the top of the right hemidiaphragm could be detected by our method almost as accurately as by manual annotation, demonstrating the usefulness of our method in the clinical setting.

Pan-ki Kim¹, David C. Wendell², Eun-Ah Park³, Whal Lee³, Hyeonjin Kim¹, and Wolfgang G. Rehwald^2,4
1Seoul National University, Seoul, Korea, ²Duke University, Durham, NC, United States, ³Seoul National University Hospital, Seoul, Korea, ⁴Siemens Healthcare Cardiac MR R&D, Chicago, IL, United States

A recently developed T2-preparation module for cardiac imaging at high field is insensitive to B0 and B1 inhomogeneity, cardiac motion and flow. Obtained T2 weighted images exhibit bright fat signal that can obscure the signal of myocardium and other muscles. Therefore, a chemical selective saturation (CHESS) is usually applied for fat suppression after the T2-preparation, e.g. in coronary artery MRI. Its quality is often poor and it is unsuited for longer readout durations. In this study, we propose a new fat suppressed T2-preparation module for 3T using binomial composite RF pulses as 90 ° pulses to more efficiently suppress fat, maintaining robustness towards inhomogeneity, cardiac motion, and flow.

Sebastian Weingärtner^1,2, Mehmet Akçakaya¹, Warren J. Manning¹, and Reza Nezafat^1
1Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, United States, ²Computer Assisted Clinical Medicine, University Medical Center Mannheim, Heidelberg University, Mannheim, Germany

We propose an adaptive coil selection scheme for self-gated coronary MRI. The coil selection is based on the motion profile observed by numerous receive coils. Coils which do not receive the respiratory motion trend are discarded. This allows for an adaptive number of discarded coils based on the size of the region of interest. Coil selection can be used to reduce the amount of data, accelerating data handling and post-processing.

Shuhei Nitta¹, Taichiro Shiodera¹, Tomoyuki Takeguchi¹, Shigehide Kuhara², Kenichi Yokoyama³, Rieko Ishimura³, and Toshiaki Nitatori^3
1Corporate Research & Development Center, Toshiba Corporation, Kawasaki, Kanagawa, Japan, ²MRI Systems Division, Toshiba Medical Systems Corporation, Otawara, Tochigi, Japan, ³Department of Radiology, Faculty of Medicine, Kyorin University, Mitaka, Tokyo, Japan

Automatic slice alignment is important in cardiac MR examinations. However, previous work has focused on only left ventricular planes. In this paper, we propose a new knowledge-based automatic slice-alignment method which can detect six left ventricular planes and four right ventricular planes simultaneously using ECG-gated axial multislice images. The results of the present study showed that the proposed method successfully detected all planes in 55 datasets from 23 healthy volunteers. The processing time was about 2.5 seconds on a 3.0-GHz CPU. The results also showed that the proposed method is beneficial to both operators and patients.

Cristobal Arrieta^1,2, Sergio Uribe^2,3, Daniel Hurtado^2,4, Marcelo Andia³, Pablo Irarrázabal^1,2, and Cristian Tejos^1,2
1Electrical Engineering, Pontificia Universidad Catolica de Chile, Santiago, Santiago, Chile, ²Biomedical Imaging Center, Pontificia Universidad Catolica de Chile, Santiago, Santiago, Chile, ³Radiology, Pontificia Universidad Catolica de Chile, Santiago, Santiago, Chile, ⁴Structural Engineering, Pontificia Universidad Catolica de Chile, Santiago, Santiago, Chile

Cardiac performance is typically assessed measuring ventricular volumes using Simpson’s rule, over short axis cine MRI scans. Heart functional indexes, such as end-systole volume, end-diastole volume or stroke volume, are usually computed from manual segmentations performed by an expert. This process is tedious and time consuming. We proposed a method based on Level Sets with preserved topology that allows to segment the left and right ventricles simultaneously without increasing the computation time, nor using any training data, and requiring minimal human intervention. Bland Altman analyses showed that our method has an excellent agreement with manual segmentations.

Hui Wang¹, Christian T. Stoeck², Sebastian Kozerke², and Amir A. Amini^1
1University of Louisville, Louisville, KY, United States, ²Institute for Biomedical Engineering, ETH, Zurich, Switzerland

In this abstract, we propose a novel 3D sine wave modeling (3D SinMod) approach for automatic analysis of 3D cardiac deformations from 3D complementary spatial modulation of magnetization (CSPAMM) MRI. The entire framework from data acquisition to data analysis is in 3D, permitting quantification of both the in-plane and through-plane components of motion

Avan Suinesiaputra¹, Brett R. Cowan¹, Pau Medrano-Gracia¹, Daniel C. Lee², and Alistair A. Young^1
1Anatomy with Radiology, The University of Auckland, Auckland, New Zealand, ²Feinberg Cardiovascular Research Institute, Northwestern University, Chicago, IL, United States

In this study, we calculated regional ejection fraction (EF) from a 4D left-ventricular mathematical model derived from cine MRI. We investigated the potential of using this to distinguish abnormal segments in ischaemic patients, which are currently clinically assessed by (regional) visual scoring. In general, regional EF is well correlated with visual wall motion scoring and late gadolinium enhancement. Normal regional EF varied between regions with the highest in (S6, S12, S16) and lowest in (S2, S3).

Alejandro Roldán-Alzate¹, Philip C. Kilgas², Kevin M. Johnson², Oliver Wieben^1,2, and Christopher J. Francois^3
1Radiology, University of Wisconsin, Madison, WI, United States, ²Medical Physics, University of Wisconsin, Madison, WI, United States, ³Radiology, University of Wisconsin-Madison, Madison, WI, United States

In patients with pulmonary hypertension (PH), blood pressure and resistance in the pulmonary circulation are elevated, leading to decreases in right ventricle (RV) function. The correlation between ventricular-vascular coupling efficiency and non-invasive metrics of PA and RV function in PH is unclear. Results in this pilot study demonstrate the feasibility of 4D flow MRI for quantifying RV kinetic energy in an animal model of acute thromboembolic PH. Future studies will concentrate on the implementation of the technique for the analysis of human PH patients.

Antonella Meloni¹, Heather Zymeski², Alessia Pepe¹, Massimo Lombardi¹, and John C. Wood^2
1CMR Unit, Fondazione G. Monasterio CNR-Regione Toscana and Institute of Clinical Physiology, Pisa, Italy, ²Division of Cardiology, Children’s Hospital Los Angeles, Los Angeles, California, United States

We developed a novel transit time estimation method from CMR flow curves based on the group delay concept. Our method was superior with two commonly used methods based on full-wave half maximum and correlation approaches in terms of dependence by the temporal resolution, dependence by the curves taken into account and reproducibility.

Aurelien F. Stalder¹, Mehmet Akif Gulsun², Andreas Greiser³, and Marie-Pierre Jolly^2
1Siemens AG - Healthcare, Erlangen, Germany, ²Imaging and computer vision, Siemens Corporation - Corporate Technology, Princeton, NJ, United States, ³Siemens AG, Erlangen, Germany

Segmentation, analysis and visualization of 4D Flow data often requires manual interaction and can be complex and time-consuming. In order to overcome the complexity of the processing of such data, a fully automatic approach for visualization of 4D Flow data is presented. Based on the assumption that 4D Flow data can be classified in three kinds of regions: air/lungs, static tissues and vessels/ventricles a data clustering technique is first applied to robustly detect flow regions. Then particle traces are seeded everywhere in the flow region so as to produce fully-automatic 4D visualization of flow data.

Nils Daniel Forkert¹, Till Illies¹, Einar Goebell¹, Jens Fiehler¹, and Heinz Handels^2
1Department of Diagnostic and Interventional Neuroradiology, University Medical Center Hamburg-Eppendorf, Hamburg, Hamburg, Germany, ²Institute of Medical Informatics, University of Luebeck, Luebeck, Schleswig-Holstein, Germany

This work presents a computer-assisted method for the segmentation of the arteriovenous malformation nidus from time-of-flight (TOF) MRA datasets. Therefore, the cerebrovascular system is automatically extracted from the TOF dataset and used for a voxel-wise support vector machine classification into nidus and non-nidus vascular structures based on four features. The resulting classification dataset is used for extracting the nidus using 3D region growing. An evaluation based on fifteen datasets with available manual nidus segmentations from two observers demonstrated that the computer-aided method leads to segmentation results within the range of the inter-observer agreement but with a considerably reduced interaction time.

Holger Eggers¹ and Tim Leiner^2
1Philips Research Laboratories, Hamburg, Germany, ²Department of Radiology, University Medical Center Utrecht, Utrecht, Netherlands

In contrast to the established subtraction approach, the recently proposed subtractionless approach to first-pass peripheral angiography based on dual-echo Dixon imaging removes only the fat signal, but not the water signal from the background. In this work, an image processing method is described that allows separating the water signal in the background from the enhanced water signal in the vessels and thus tailoring the extent of background signal remaining in particular in the maximum intensity projections calculated for the visualization of the vasculature to individual preferences.

Xiaoying Cai¹, Feiyu Chen², Enhao Gong³, Shi Wang⁴, and Kui Ying^4
1Biomedical Engineering, Tsinghua University, Beijing, Beijing, China, ²Department of Biomedical Engineering, Tsinghua University, Beijing, Beijing, China, ³Electrical Engineering, Stanford University, Stanford, CA, United States, ⁴Department of Engineering Physics, Tsinghua University, Beijing, Beijing, China

In this study, we proposed a new framework of combining k-t FOCUSS and a nonlinear filter compressed sensing for high spatial/ temporal resolution real-time imaging by sufficiently exploring image sparsity of k-t domain and gradient. Simulation results demonstrate the proposed method performs better in eliminating artifacts and keeping structure details.

Anup Singh¹, Mohammad Haris¹, Kejia Cai¹, Feliks Kogan¹, Walter R.T. Witschey^1,2, Gerald A. Zsido², Jeremy McGarvey², Ravi Prakash Reddy Nanga¹, Francisco Contijoch³, James J. Pilla⁴, Joseph H. Gorman², Victor A. Ferrari⁵, Hari Hariharan¹, Robert C. Gorman², and Ravinder Reddy^1
1CMROI, Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, United States, ²Department of Surgery, University of Pennsylvania, Philadelphia, Pennsylvania, United States, ³Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, United States, ⁴Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, United States, ⁵Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States

Objective of current study was to address the challenges associated with CEST contrast computation through conventional asymmetry analysis in in vivo myocardium tissues particularly due to fluctuating B₀ inhomogeneity (~[-0.2, 0.2]ppm), motion artifacts and low SNR. To address these challenges we adopted an approach of fitting z-spectra data with a function of Lorentzian functions. It is demonstrated that this approach mitigates artifacts due to motion and B₀ fluctuations and enables the CEST contrast computation in in vivo myocardium data. Moreover, there is no need for acquire B₀ field inhomogeneity correction as the center of water resonance is one of the parameters in fitting function.

Hsin-Jung Yang^1,2 and Rohan Dharmakumar^1
1Cedars-Sinai Medical Center, Los Angeles, California, United States, ²Biomedical Engineering, University of California, Los Angeles, California, United States

Studies have shown that bSSFP-based myocardial Blood-oxygen-Level-Dependent (BOLD) contrast is directly dependent on repetition time (TR). However, in the presence of field inhomogeneities, image artifacts scale with TR. Although the multiple acquisitions technique has been used to mitigate against banding artifacts, its applicability in cardiac imaging has not been investigated. In this work, we demonstrate that an optimized dual acquisition strategy combined with flow compensation may be a viable means for achieving robust image quality for myocardial cine BOLD MRI at 3T.

Vincenzo Positano¹, Antonella Meloni¹, Maria Filomena Santarelli¹, Luigi Landini¹, Carmelo Fidone², Maria Antonietta Romeo³, Letizia Gulino¹, Elisabetta Chiodi⁴, Antonino Vallone⁵, Massimo Lombardi¹, and Alessia Pepe^1
1CMR Unit, Fondazione G. Monasterio CNR-Regione Toscana and Institute of Clinical Physiology, Pisa, Italy, ²U.O.S. di Microcitemia, Az. Osp. Civile, O.M.P.A. di Ragusa, Ragusa, Italy,³Dipartimento Pediatria, Azienda Policlinico, Catania, Italy, ⁴Servizio Radiologia Ospedaliera-Universitaria, Arcispedale “S. Anna” di Ferrara, Ferrara, Italy, ⁵Istituto di Radiologia Az. Osp. "Garibaldi", Presidio Ospedaliero Nesima, Catania, Italy

T2* multislice multiecho MRI allows quantification of myocardial iron overload by fitting the signal decay curves to a mono-exponential model. In patients with severe cardiac iron overload, where the signal decays quickly becoming comparable to image noise, manual truncation of signal decay curves excluding later echo times is adopted. In this study we present an automatic truncation method that avoids the variability associated with the manual selection of the truncation point.

Liang Zhong¹, Min Wan¹, Jun Mei Zhang¹, and Ru San Tan^1
1National Heart Centre Singapore, Singapore, Singapore, Singapore

A novel method for automatic localization of left ventricle (LV) via spectrum analysis in magnetic resonance imaging is proposed. Two temporal approaches based on the variance image and the first harmonic image are applied and reformulated in a unified framework to reveal their intrinsic connections. The first harmonic image and some higher harmonic image are used in an anisotropic weighted circle Hough transform. The first harmonic image votes with positive weights while the higher harmonic image votes with negative weights to suppress the right ventricular interruption. The results in 17 patients show the capability for automatic localization of LV.

Patrick Antkowiak¹, Anthony Bruce¹, Nicholas Palacio¹, Heather Ansorge², Aaron Barere², Shayn Peirce-Cottler³, and Frederick H. Epstein^3
1University of Virginia, Charlottesville, VA, United States, ²LifeCell Corporation, Branchburg, NJ, United States, ³Biomedical Engineering, University of Virginia, Charlottesville, Virginia, United States

Regenerative tissue matrix is widely used to enhance tissue repair. Vascularization is a critical element of enhancing tissue repair with tissue matrix because a blood supply is needed to support tissue regeneration. Dynamic contrast-enhanced MRI (DCE-MRI) is widely used to quantify changes in vascularity in various disease settings. We tested the hypothesis that DCE-MRI could noninvasively quantify serial changes in vascularity over time after implantation of a regenerative tissue matrix in mice. We measured stepwise increases of vascularity in the tissue matrix, while vascularity within skeletal muscle remained unchanged. Histology corroborated the increase in vasculature in the matrix through time.

Joshua F. P. van Amerom^1,2, Christopher M. Wernik³, Venkat Ramanan⁴, Graham A. Wright^3,4, and Christopher K. Macgowan^2,3
1Labatt Family Heart Centre, Div. of Cardiology, Dept. of Paediatrics, Hospital for Sick Children, Toronto, ON, Canada, ²Dept. Of Diagnostic Imaging, Hospital for Sick Children, Toronto, ON, Canada, ³Dept. of Medical Biophysics, University of Toronto, Toronto, ON, Canada, ⁴Imaging Research, Sunnybrook Health Sciences Centre, Toronto, ON, Canada

MR oximetry based on quantitative T2 measurement is a noninvasive technique for measuring blood oxygen saturation. In this study, we apply an improved technique, Magnetic resonance Oximetry with Velocity Encoding, in vivo. This technique uses Fourier velocity encoding to isolate moving blood from static tissue based on velocity.

Larry A. Kramer¹, Allan M. Cohen¹, Jared H. Heimbigner¹, William K. Carson¹, Andrew D. Barreto², Staley A. Brod², Ponnada A. Narayana¹, and Jerry S. Wolinsky^2
1Diagnostic Imaging and Intervention, UTHSC-Houston, Houston, Texas, United States, ²Department of Neurology, UTHSC-Houston, Houston, Texas, United States

Contrast-enhanced magnetic resonance venography with gadofosveset trisodium can be utilized as a comprehensive evaluation of the intracranial and extracranial venous system with minimal artifacts and time efficient acquisition. Excellent correlation with conventional venography was achieved.

Sathya Vijayakumar^1,2, Nassir F. Marrouche², and Eugene G. Kholmovski^1,2
1UCAIR, Dept. of Radiology, University of Utah, Salt Lake City, Utah, United States, ²CARMA, Dept. of Cardiology, University of Utah, Salt Lake City, Utah, United States

This work studies the scar visibility in LGE-MRI of the Left Atrium as a function of acquisition time post contrast injection.

Yijen Lin Wu¹, Li Liu¹, Qing Ye¹, Brent D. Barbe¹, T. Kevin Hitchens¹, and Chien Ho^1,2
1Pittsburgh NMR Center for Biomedical Research, Carnegie Mellon University, Pittsburgh, PA, United States, ²Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, United States

Cellular MRI with iron-oxide based contrast agents offers the potential to track many cell types in vivo at high resolution. The newly modified ITRI-IOPC-NH2 particles with increased positive charge and terminal amino groups can label T-lymphocytes by simple co-incubation without eternal aids. Our results show that T-lymphocytes and macrophages exhibit different temporal appearance behavior in the rejecting cardiac allograft, indicating that they may play different roles in rejection.