Jochen Franke^1,2, Nicoleta Baxan³, Ulrich Heinen¹, Alexander Weber^1,4, Heinrich Lehr¹, Martin Ilg¹, Wolfgang Ruhm¹, Michael Heidenreich¹, and Volkmar Schulz^2
1Preclinical Imaging Devision, Bruker BioSpin MRI GmbH, Ettlingen, Germany, ²Physics of Molecular Imaging Systems, University RWTH Aachen, Aachen, Germany, ³Biomedical Imaging Centre, Imperial College London, London, United Kingdom, ⁴Institute of Medical Engineering, University of Lübeck, Lübeck, Germany

Using a highly integrated Magnetic Particle Imaging – Magnetic Resonance Imaging hybrid system, a dual-modal cardiovascular in vivo assessment in rodents under the usage of a non-toxic Resovist dosage was performed successfully. The subject was imaged sequentially in both modality modes, whereas neither subject repositioning nor anesthesia interruption were required. Complementary datasets were acquired within a single seamless multi-modal study using ParaVison6 (Bruker BioSpin, Germany) allowing direct MRI-based MPI Field-of-View planning. After reconstructing time-resolved (TR=21.45 ms) 3D MPI images of the bolus-passage they were successfully fused with a high-resolution static 3D MRI dataset and visualized as combined 4D/3D hybrid dataset.

Shuo Chen¹, Zechen Zhou¹, Rui Li¹, Xihai Zhao¹, Huijun Chen¹, Changwu Zhou^1,2, Bida Zhang³, and Chun Yuan^1,4
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China, People's Republic of, ²Department of Radiology, Yangzhou First People's Hospital, Yangzhou, China, People's Republic of, ³Healthcare Department, Philips Research China, Shanghai, China, People's Republic of, ⁴Vascular Imaging Laboratory, Department of Radiology, University of Washington, Seattle, WA, United States

The aim of this study was to develop a Hybrid Interleaved Multicontrast Imaging (HIMI) sequence for simultaneous brain and carotid vessel wall imaging. The proposed HIMI sequence takes advantage of the long delay time in conventional 3D FLAIR sequence to acquire multi-contrast carotid vessel wall images. Four healthy volunteers were recruited in this study. The results indicate that HIMI can generate a comparable FLAIR image with conventional FLAIR sequence and three more different contrast weighted (T1w, T2w, gray blood) carotid vessel wall images with the same scan time as a single conventional 3D FLAIR sequence.

Jerome Yerly^1,2, Danilo Gubian³, Jean-Francois Knebel^2,4, Thomas Robin⁵, Giulia Ginami¹, and Matthias Stuber^1,2
1CardioVascular Magnetic Resonance (CVMR) research center, Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland, ²Center for Biomedical Imaging (CIBM), Lausanne, Switzerland, ³University Hospital (CHUV), Lausanne, Switzerland, ⁴Laboratory for Investigative Neurophysiology (The LINE), Departments of Radiology and Clinical Neurosciences, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland, ⁵Transport and Mobility Laboratory (TRANSP-OR), Swiss Federal Institute of Technology of Lausanne (EPFL), Lausanne, Switzerland

MRI with isometric handgrip exercise was recently proposed to non-invasively assess coronary endothelial function. However, the sensitivity of this technique has not yet been fully investigated. To address this need, we have designed a phantom that simulates a physiological range of coronary cross-sectional areas. Radial cine MR images with different spatial resolutions were acquired under moving conditions. Cross-sectional areas were automatically measured and compared to the known nominal values. Statistical analysis suggests that MRI is capable of distinguishing area changes in the order of 0.2-0.3mm², which correspond to a percentage coronary area change of 3-4% for a 3mm baseline diameter.

Katsumi NAKAMURA^1,2, Akiyoshi Yamamoto¹, Hiroki Matoba¹, Yuji Shintani¹, Daiji Uchiyama¹, Seigo Yoshida¹, and Mitsue Miyazaki^3
1Radiology, Tobata Kyoritsu Hospital, Kitakyushu, Japan, ²Nexus Image Lab, Kitakyushu, Japan, ³Toshiba Medical Research Institute USA, Inc., Vernon Hills, IL, United States

We compared the diagnostic ability of FBI with that of CTA  with using a calcification removal tool in the evaluation of the lower-extremity arteries with wall calcifications. In all segments, FBI provided diagnostic images regardless of the degree of wall calcification.  On the contrary, CTA-MIP and CTA-MIP w/o Ca were strongly affected by calcification. The diagnostic ability of FBI was significantly superior to that of CTA-MIP and CTA-MIP w/o Ca in the moderate to severe calcified arterial segments. In conclusion, FBI is an accurate and noninvasive alternative to CTA for the assessment of aortoiliac and lower extremity arteries in patients with PAD.

Davide Piccini^1,2, Li Feng³, Gabriele Bonanno², Simone Coppo², Jérôme Yerly^2,4, Ruth P. Lim⁵, Juerg Schwitter⁶, Daniel K. Sodickson³, Ricardo Otazo³, and Matthias Stuber^2,4
1Advanced Clinical Imaging Technology, Siemens Healthcare, Lausanne, Switzerland, ²Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland,³Center for Advanced Imaging Innovation and Research, New York University School of Medicine, New York City, NY, United States, ⁴Center for Biomedical Imaging (CIBM), Lausanne, Switzerland,⁵Department of Radiology, Austin Health and The University of Melbourne, Melbourne, Australia, ⁶Division of Cardiology and Cardiac MR Center, University Hospital of Lausanne (CHUV), Lausanne, Switzerland

We hypothesize that sparse reconstruction algorithms can be exploited to reconstruct respiratory motion-resolved 3D MRA images of the heart without the need for breath-holding, navigators, or self-navigated respiratory motion correction. Phantom, volunteer, and patient acquisitions were performed and image quality was compared to 1D self-navigation for vessel sharpness, length and diagnostic quality. Respiratory motion-resolved reconstruction effectively suppresses respiratory motion artifacts with superior results with respect to self-navigation. Instead of discarding data or enforcing motion models for motion correction, motion-resolved reconstruction makes constructive use of all respiratory phases to improve image quality, and may lead coronary MRA closer to clinical practice.

Ronald J Beyers¹, Davis M Vigneault², Dean Schwartz³, Nouha Salibi^1,4, David A Bluemke², and Thomas Denney^1
1MRI Research Center, Auburn University, Auburn University, AL, United States, ²Radiology and Imaging Sciences, National Institutes of Health, Bethesda, MD, United States, ³Anatomy, Physiology and Pharmacology, Auburn University, Auburn University, AL, United States, ⁴MR R&D, Siemens Healthcare, Malvern, PA, United States

We developed a Cine Watermark (CWM) cine sequence that produces normal cine magnitude images, plus a grid pattern of tags added only in the phase for quantitative cine strain, while requiring no extra operator effort.  Using spatial cosine modulation combined with k-space sum/differencing produced separate normal magnitude cine and unique phase-only grid-tags for strain calculation.  In vivorat and human scans demonstrated good magnitude cine and phase-only quantified displacement. Calculated by Farneback optical flow algorithm, the peak principle strain, averaged around the LV for rat = -16.5±2.4 % and human = -17.8±6.2 % (mean±StdDev).

Joshua FP van Amerom¹, Maria Kuklisova Murgasova¹, Anthony N Price¹, Shaihan J Malik¹, Paul Aljabar², David A Lloyd¹, Kuberan Pushparajah^1,3, Maelene Lohezic¹, Matthew J Fox², Joanna M Allsop², Mary A Rutherford^1,2, Reza Razavi^1,3, and Joseph V Hajnal^1
1Division of Imaging Sciences & Biomedical Engineering, King's College London, London, United Kingdom, ²Centre for the Developing Brain, King's College London, London, United Kingdom, ³Department of Congenital Heart Disease, Evelina London Children's Hospital, London, United Kingdom

Motion is a key limiting factor in fetal cardiac MRI as the small, rapidly beating heart is subject to various periodic and spontaneous motions. Highly accelerated real-time imaging with high temporal resolution was used to obtain serial ‘snapshots’ of the fetal heart and surrounding anatomy that could be motion-corrected and reassembled, combining several cardiac cycles into a single heartbeat. A super-resolution reconstruction was applied to increase the visibility of dynamic anatomical features in the densely sampled data. The resulting cine images provide a clear depiction of dynamic cardiac features.

Jerome Chaptinel¹, Yvan Mivelaz², Jerome Yerly^1,3, Leonor Alamo¹, Milan Prsa², Yvan Vial⁴, François Gudinchet¹, Gregoire Berchier¹, Jean-Baptiste Ledoux¹, and Matthias Stuber^1,3
1Department of Radiology, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland, ²Department of Pediatrics, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland, ³Center for Biomedical Imaging (CIBM), Lausanne, Switzerland, ⁴Department of Gynecology-Obstetrics, University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland

Fetal cardiac cine MRI is challenging due to the lack of an ECG trigger signal, fetal motion, and the need for both a high spatial and temporal resolution. To overcome these hurdles, we have developed and tested a new acquisition-reconstruction paradigm: data collection was performed with a continuous radial golden-angle acquisition and cine images were reconstructed with a k-t sparse SENSE algorithm. A cardiac gating signal was extracted from the images themselves and supported self retro-gated reconstructions in which motion-corrupted data were excluded. Fetal self retro-gated cardiac cine images with high temporal and spatial resolution were successfully obtained in pregnant patients.

Laura Claire Saunders¹, Neil J Stewart¹, Charlotte Hammerton¹, David Capener¹, Valentina O Puntmann², David G Kiely³, Martin J Graves⁴, Andy Swift¹, and Jim M Wild^1
1Academic Unit of Radiology, The University of Sheffield, Sheffield, United Kingdom, ²Department of Cardiovascular Imaging, Kings College London, London, United Kingdom, ³The University of Sheffield, Sheffield, United Kingdom, ⁴University of Cambridge School of Clinical Medicine, University of Cambridge, Cambridge, United Kingdom

Patients with suspected pulmonary hypertension (n=94) and healthy volunteers (n=26) underwent T1 mapping of the right ventricle with a Modified Look Locker inversion recovery (MOLLI) sequence at 1.5T. MOLLI images were registered using pairwise registration to synthetic images produced using a simplified inversion recovery model to correct cardiac or respiratory motion. 89% of patients and 100% of healthy volunteers were successfully registered, with mean T1s of 1.00±0.10s and 0.97±0.06s (septal), 1.05±0.11s and 0.97±0.06s (right ventricular insertion point) and 1.02±0.11s and 1.04±0.13s (right ventricular free wall) respectively.

Maurce Pradella¹, Sven Knecht², Michael Kühne², Aline Mühl², Tobias Reichlin², Gian Voellmin², David Conen², Jens Bremerich¹, Stefan Osswald², Christian Sticherling², and Bram Stieltjes^1
1Department of Radiology, University of Basel Hospital, Basel, Switzerland, ²Department of Cardiology, University of Basel Hospital, Basel, Switzerland

Atrial fibrillation (AF) is a common disease and associated with myocardial infarction, stroke and dementia. We propose a new approach based on the sphericity of fitted ellipsoids in left atriums of patients with AF. Our results show a strong correlation between sphericity of these ellipsoids and burden of disease and may serve as an objective surrogate parameter in the future.

Adam Rich¹, Lee C. Potter¹, Ning Jin², Juliana Serafim da Silveira³, Orlando P. Simonetti³, and Rizwan Ahmad^3
1Electrical and Computer Engineering, The Ohio State University, Columbus, OH, United States, ²Siemens Medical Solutions, The Ohio State University, Columbus, OH, United States, ³Dorthy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States

Phase-contrast magnetic resonance is a powerful tool for study of cardiac flow, but clinical application is limited to planar imaging of one velocity component. This abstract demonstrates three-directional flow imaging using a single breath-hold acquisition.  Imaging is accomplished by jointly processing all encodings and frames; Bayesian reconstruction leverages image structure via both wavelet compression and statistical relations among velocity encoded images. Digital phantom results show accurate estimation of stroke volume and peak velocity, with significant reductions in bias and variance, as well as over 30% increase in Pearson correlation coefficient, compared to L1-SENSE. In vivo results demonstrate repeatable flow estimation.

Edward DiBella¹, Devavrat Likhite¹, Ganesh Adluru¹, Chris Welsh¹, and Brent Wilson^1
1University of Utah, Salt Lake City, UT, United States

Here we propose a unique perfusion acquisition that uses one saturation pulse per heartbeat. This combined with simultaneous multi-slice (SMS) methods allows for acquiring the same set of slices continuously through the cardiac cycle. This has a number of advantages including the ability to retrospectively reconstruct an accurate arterial input function (AIF) and optimized systolic/diastolic frames, or other portions of the cardiac cycle. The approach proposed here acquires both k-space rays that reflect the influence of the saturation pulse and other rays that reflect the steady-state GRE contrast, and thus is termed the “hybrid” method.  Preliminary quantitative results including comparisons to more standard methods in two subjects show the promise of this SMS approach.

Alexander Gotschy^1,2, Christian Binter¹, Simon H Sündermann³, Michelle Frank², Felix C Tanner², Robert Manka², and Sebastian Kozerke^1
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland, ²Department of Cardiology, University Hospital Zurich, Zurich, Switzerland, ³Division of Cardiovascular Surgery, University Hospital Zurich, Zurich, Switzerland

Aortic stenosis (AS) is the most prevalent valvular heart disease. Risk stratification and the decision for valve replacement are mostly based on echocardiography and symptomaticity. This work investigates the additional value of quantifying Turbulent Kinetic Energy (TKE) for the assessment of AS severity beyond echocardiographic measures. TKE was confirmed to be significantly elevated in patients with AS compared to controls. While TKE showed only weak correlation with the echocardiographic Mean Pressure Gradient, TKE allowed to discriminate the impact of bicuspid aortic valves and aortic dilatation on energy loss in AS patients; effects which are not assessable by standard echocardiographic measures.

Ria Mazumder^1,2, Samuel Schroeder^2,3, Xiaokui Mo⁴, Bradley D Clymer⁵, Richard D White^2,6, and Arunark Kolipaka^2,6
1Department of Electrical and Computer Enginerring, The Ohio State University, Columbus, OH, United States, ²Department of Radiology, The Ohio State University, Columbus, OH, United States,³Department of Mechanical Engineering, The Ohio State University, Columbus, OH, United States, ⁴Department of Biomedical Informatics, The Ohio State University, Columbus, OH, United States,⁵Department of Electrical and Computer Engineering, The Ohio State University, Columbus, OH, United States, ⁶Department of Internal Medicine-Division of Cardiovascular Medicine, The Ohio State University, Columbus, OH, United States

Left ventricular (LV) myocardial stiffness (MS) is elevated in heart failure with preserved ejection fraction (HFpEF) and hence has the potential to be used as a diagnostic tool. Current clinical techniques to estimate LV MS are invasive in nature and provides global stiffness measurements. Therefore, in this study, we implement cardiac magnetic resonance to investigate temporal alteration in LV MS over a two month period of disease progression in a porcine model induced with HFpEF. The alteration in LV MS is compared against change in mean LV pressure, LV thickness, circumferential strain and MRI relaxometry parameters.

Volker Herold¹, Patrick Winter¹, Philipp Mörchel², Fabian Gutjahr¹, and Peter Michael Jakob^1
1Department of Experimental Physics 5, University of Wuerzburg, Wuerzburg, Germany, ²Research Center for Magnetic Resonance Bavaria e.V., Wuerzburg, Germany

Phase-Contrast (PC) cine MRI is an established method for the assessment of blood flow and tissue motion patterns in cardiovascular MRI. In this paper we presented a highly accelerated self-gated PC-MRI-sequence based on free breathing random sampled data acquisition. Data acquired during respiratory motion as well as any other source of undesirable motion can be excluded from the post-processing. Moreover ECG-signal acquisition which is prone to distortions especially at higher field strength can be avoided. The high flexibility of data processing would also allow the correction of unstable heart rate during the measurement. 

Behzad Sharif¹, Rohan Dharmakumar¹, Daniel Berman², Debiao Li¹, and Noel Bairey Merz^2
1Biomedical Imaging Research Institute, Dept of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, United States, ²Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States

A significant portion of patients with ischemic heart disease suffer from coronary microvascular dysfunction. Despite intense interest and several recent advancements, reliable diagnosis of coronary microvascular dysfunction on the basis of stress first-pass perfusion (FPP) cardiac MRI is an ongoing challenge. We hypothesized that high-resolution systolic FPP imaging can detect diffuse vasodilator-induced subendocardial defects and transmural perfusion gradients consistent with microvascular dysfunction in a swine model of diet-induced diabetes with no obstructive disease. To this end, we developed, optimized, and tested a new high-resolution FPP method with hybrid 2D/3D excitation capable of imaging all myocardial slices at the end-systolic phase.