Xiaoyong Zhang^1,2, Guoxi Xie², Yanchun Zhu², Zijun Wei², Caiyun Shi², Shi Su², Fei Yan², Hairong Zheng², Bensheng Qiu¹, Xin Liu², and Zhaoyang Fan^3
1University of Science and Technology of China, Hefei, China, People's Republic of, ²Shenzhen Institutes of Advanced Technology, Shenzhen, China, People's Republic of, ³Cedars-Sinai Medical Center, Los Angeles, CA, United States

An accelerated self-gating (SG) technique, SparseSG, was developed to realize whole-heart coverage of 3D cardiac cine imaging at 3T without ECG and breath-holding. Preliminary in vivo study demonstrated that a whole heart coverage of 3D cine imaging can be achieved within 1 min and the technique had excellent performance compared to the standard ECG-triggering and conventional SG methods.

Lea Schroeder¹, Jens Wetzl^1,2, Andreas Maier^1,2, Robert Rehner³, Matthias Fenchel⁴, and Peter Speier^4
1Pattern Recognition Lab, Department of Computer Science, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany, ²Erlangen Graduate School in Advanced Optical Technologies, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany, ³Magnetic Resonance, Research and Development, Hardware, Siemens Healthcare GmbH, Erlangen, Germany, ⁴Magnetic Resonance, Product Definition and Innovation, Siemens Healthcare GmbH, Erlangen, Germany

Pilot Tone signals, generated by a commercial signal generator and received with standard MR local coils, were analyzed for multidimensional respiratory information. The ground truth for respiratory motion in two orthogonal directions ($$$\boldsymbol{g}_{SI}$$$ and $$$\boldsymbol{g}_{AP}$$$), generated by sagittal image streams of the right liver dome using standard fluoroscopic sequences, showed excellent correlation with the PT signal derived from a separate measurement (for $$$\boldsymbol{g}_{SI}$$$: 0.90 $$$\pm$$$0.13; for $$$\boldsymbol{g}_{AP}$$$: 0.82 $$$\pm$$$0.21). Our results demonstrate that PT navigation can provide two-dimensional characterization of regular and irregular respiratory motion without interfering with the MR measurement.

Kostas Haris^1,2, Erik Hedstrom^2,3, Sebastian Bidhult², Frederik Testud⁴, George Kantasis^1,2, Henrik Engblom², Marcus Carlsson², Nicos Maglaveras¹, Einar Heiberg², Stefan R Hansson⁵, Hakan Arheden², and Anthony H Aletras^1,2
1Laboratory of Medical Informatics, Department of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece, ²Lund Cardiac MR Group, Department of Clinical Physiology and Nuclear Medicine, Skåne University Hospital, Lund University, Lund, Sweden, ³Department of Diagnostic Radiology, Skåne University Hospital, Lund University, Lund, Sweden, ⁴Siemens Healthcare AB, Malmoe, Sweden,⁵Department of Obstetrics and Gynecology, Skåne University Hospital, Lund University, Lund, Sweden

The aim of this study was to demonstrate the feasibility of CINE fetal MRI within a breath-hold with self-gated retrospective binning applied with continuous golden angle radial sampling and iGRASP acceleration. A bSSFP radial acquisition scheme was applied with 0.7x0.7mm² in-plane resolution and a small golden angle of 23.1^o. A total of 3800 radial spokes were acquired within a breath hold of 15s. Cardiac triggering was obtained from the centers of the readouts via Principal Component Analysis. The final images were obtained by using iGRASP. Good quality CINE images from the fetus in the third trimester were acquired.

Sebastian Weingartner^1,2,3, Greg Metzger², Pierre-Francois Van de Moortele², and Mehmet Akcakaya^1,2
1Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, United States, ²Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States,³Computer Assisted Clinical Medicine, University Medical Center Mannheim, Heidelberg University, Mannheim, Germany

For various cardiac MRI appications, having B1 maps that are cardiac phase-resolved may be beneficial at high fields.  In this work, we developa retrospectively ECG-gated sequence based on the actual flip angle imaging technique for 2D cardiac phase-resolved B1 mapping at 3T. 

Haiying Tang¹, Matthew Fronheiser¹, Harold Malone¹, Paul Sleph², Adrienne Pena¹, Thomas Petrone¹, Thomas Bradstreet¹, Patrick Chow¹, Lei Zhao², David Gordon², Feng Luo³, and Wendy Hayes^1
1Bristol Myers Squibb, Princeton, NJ, United States, ²Bristol Myers Squibb, Hopewell, NJ, United States, ³Bristol Myers Squibb, Wallingford, CT, United States

Recent advances in cardiovascular MRI (CMR) technologies such as T1-mapping or extracellular volume (ECV) fraction (derived from T1-mapping) offer robust techniques to assess diffuse fibrosis in patients with myocardial infarction and heart failure. In the present study, CMR assessment of myocardial fibrosis and hypertrophy was evaluated in an isoproterenol infusion model in Balb/c mice. The CMR techniques including T1-mapping and the ECV quantification provide a translational non-invasive imaging marker to assess diffuse myocardial fibrosis, and the potential to evaluate efficacy of anti-fibrosis treatment.

Mark David Meadowcroft^1,2, Timothy Cooper³, Michele Ferenci², Elizabeth B Neely¹, Ephraim Church¹, Thaddeus Wright¹, Sebastian Rupprecht², Weimin kang¹, Jenelle Tretter³, Qing X Yang², Robert E Harbaugh¹, James R Connor¹, and James Mcinerney^1
1Neurosurgery, The Pennsylvania State University - College of Medicine, Hershey, PA, United States, ²Radiology, The Pennsylvania State University - College of Medicine, Hershey, PA, United States,³Comparative Medicine, The Pennsylvania State University - College of Medicine, Hershey, PA, United States

Current treatment options for un-ruptured intracranial aneurysms typically include open clipping, endovascular embolization, or observation. We undertook this study to examine the effects of GKRS on an in vivo rabbit aneurysm model.  Involution of aneurysms after GKRS could provide a safer and more cost-effective treatment alternative for patients harboring un-ruptured intracranial aneurysms.  The results of the study reveal a 40 percent reduction in aneurysm total volume, internal volume, and surface area over the 24-month period.  Targeted GKRS is successful in promoting histological and hemodynamic changes to the rabbit carotid aneurysm, linearly reducing size over time.  

Zhi Zuo^1,2,3, Anne Subgang^2,3, Alireza Abaei³, Gen-shan Ma¹, and Volker Rasche^2,3
1Department of Cardiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, China, People's Republic of, ²Department of Internal Medicine II, University Hospital Ulm, Ulm, Germany,³Core Facility Small Animal MRI, Medical Faculty, Ulm University, Ulm, Germany

Cardiovascular magnetic resonance (CMR) has emerged as the most accurate imaging modality for noninvasive assessments of left ventricular (LV) structure and function in mice. However, data on the longitudinal variability of LV systolic function assessment in mice is still limited. In this contribution, a one year follow-up of the longitudinal reproducibility of the LV function and mass has been performed at 11.7T with self-gated CINE MRI. The investigated protocol was proven reliable for the evaluation of EF, EDV, ESV, SV and LVM data.

Christopher Nguyen¹, Zhaoyang Fan¹, Yibin Xie¹, Jianing Pang¹, Xiaoming Bi², Peter Speier³, Jon Kobashigawa⁴, and Debiao Li^1,5
1Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, ²MR R&D, Siemens Healthcare, Los Angeles, CA, United States, ³Siemens Healthcare GmbH, Erlangen, Germany, ⁴Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, ⁵Bioengineering, University of California Los Angeles, Los Angeles, CA, United States

Optimized second order motion compensated (M2) diffusion tensor prepared cardiac magnetic resonance (DT-CMR) was applied in healthy volunteers and heart failure patients at 3T. The pulse sequence design focused on B1 robustness at high main field. In healthy volunteers, the proposed M2 DT-CMR was compared to zero order (M0) and first order (M1) motion compensations. In addition, heart rate dependency of the proposed M2 DT-CMR was explored with contextual comparison to M0 and M1. M2 DT-CMR was the only technique capable of application in heart failure patients without bulk motion artifacts. 

Christopher Nguyen¹, Peter Speier², Xiaoming Bi³, and Debiao Li^1,4
1Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, ²Siemens Healthcare GmbH, Erlangen, Germany, ³Siemens Healthcare, Los Angeles, CA, United States, ⁴Bioengineering, University of California Los Angeles, Los Angeles, CA, United States

Clinical application of diffusion-weighted cardiac magnetic resonance (DW-CMR) has demonstrated promise in detecting and characterizing the tissue microphysiology and/or microstructure.  The aim of this study is to compare a recently developed SE diffusion-prepared approach with a conventional STE DW-CMR technique in normal volunteers on a 3T system. M2-SE derived MD values were significantly higher than STE derived values despite the same prescribed b-value and the difference is not dependent on heart rate. Both DW-CMR techniques were reproducible and motion corruption was seen to be overall less in M2-SE.

Choukri Mekkaoui¹, Timothy G Reese¹, Marcel P Jackowski², Stephen F Cauley¹, Kawin Setsompop¹, William J Kostis³, Himanshu Bhat⁴, and David E Sosnovik^1
1Harvard Medical School - Massachusetts General Hospital, Boston, MA, United States, ²University of São Paulo, São Paulo, Brazil, ³Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, United States, ⁴Siemens Healthcare, Boston, MA, United States

We introduce an approach to perform free-breathing DTI and tractography of the whole heart based on simultaneous multislice excitation, sequential reordering of the diffusion-encoding gradients, combined with a retrospective entropy-based image alignment and selection method. The approach was tested in 7 healthy volunteers, in whom breath-hold and free-breathing scans were performed. Coherent tracts of the entire heart could be derived in all cases, and no significant differences were seen in mean diffusivity, fractional anisotropy, or myofiber helix angle. Accelerated free-breathing DTI of the entire heart could be performed in less than 15 minutes without significant loss of image quality.

Martijn Froeling¹, Tim Leiner¹, Laura W M Vergoossen², Eibert A ten Hove², Aart J Nederveen³, Gustav J Strijkers⁴, and Peter R Luijten^1
1Radiology, UMC Utrecht, Utrecht, Netherlands, ²Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands, ³Radiology, AMC Amsterdam, Amsterdam, Netherlands,⁴Biomedical Engineering & Physics, AMC Amsterdam, Amsterdam, Netherlands

A recent study by McGill et al. showed in-vivo spatial and transmural heterogeneity of cardiac diffusion parameters. The aim of this study was to investigate the origin of DWI-parameter heterogeneity using whole heart in- and ex-vivo SE-DWI. Based on our results, transmural heterogeneity is partially explained by variations in transmural and spatial perfusion signal fraction and, partially seems to have its origin in cardiac architecture during systole.

Martijn Froeling¹, Gustav J Strijkers², Laura W M Vergoossen³, Eibert A ten Hove³, Aart J Nederveen⁴, Tim Leiner¹, and Peter R Luijten^1
1Radiology, UMC Utrecht, Utrecht, Netherlands, ²Biomedical Engineering & Physics, AMC Amsterdam, Amsterdam, Netherlands, ³Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands, ⁴Radiology, AMC Amsterdam, Amsterdam, Netherlands

The aim of this study was to provide a comprehensive description of whole heart in-vivo myocardial fiber architecture using the fiber architecture matrix, and to validate results using ex-vivo and simulated data. We showed that whole heart fiber architecture described by the FAM can be obtained from in-vivo DWI. However, compared to ex-vivo data the direction of ε₂ and ε₃ are exchanged.

Christian T Stoeck^1,2, Constantin von Deuster^1,2, and Sebastian Kozerke^1,2
1King's College London, London, United Kingdom, ²University and ETH Zurich, Zurich, Switzerland

In vivo cardiac DTI using spin-echoes has been demonstrated on MR systems equipped with powerful gradients. In this study we investigate the dependency of helix and transverse angle error on maximum gradient amplitude for second order motion compensated diffusion encoding of the in-vivo heart. Root-mean-square errors for helix and transverse angles were 15.0±3.7°, 11.0±1.8°, 10.3±2.4°, and 11.7±3.8°, 9.0±2.0°, 8.1±2.2° for gradient strengths of 30mT/m, 40mT/m and 60mT/m when compared to data obtained at 74.5 mT/m gradient strength. From the data it is concluded that second order motion compensated diffusion encoding allows for in vivo cardiac DTI even on MR systems with standard gradient amplitudes of 40 mT/m.

Andrew David Scott^1,2, Sonia Nielles-Vallespin^1,3, Pedro Ferreira^1,2, Peter Gatehouse^1,2, Zohya Khalique¹, Philip Kilner^1,2, Dudley Pennell^1,2, and David Firmin^1,2
1Cardiovascular Biomedical Research Unit, Royal Brompton and Harefield Foundation NHS Trust, London, United Kingdom, ²National Heart and Lung Institute, Imperial College London, London, United Kingdom, ³National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD, United States

In-vivo cardiac diffusion tensor imaging (cDTI) performed with a stimulated echo (STEAM) sequence is considered strain sensitive and low SNR. Alternatively, motion compensated spin-echo (M012-SE) sequences are thought to be strain insensitive and high SNR, but suffer from long echo times and short mixing times.  In this work we compare the reliability of and the cDTI parameters derived from STEAM and M012-SE data in 20 volunteers at mutliple points in the cardiac cycle on a standard clinical scanner.  We show systematic differences between the sequences and show that there are few correlations between these differences and strain and/or T1/T2. 

Eric Aliotta^1,2, Holden H Wu^1,2, and Daniel B Ennis^1,2
1Radiological Sciences, UCLA, Los Angeles, CA, United States, ²Biomedical Physics IDP, UCLA, Los Angeles, CA, United States

Bulk motion compensated diffusion encoding is critical for accurately measuring diffusion in the heart. However, the diffusion encoding gradient waveforms required to suppress bulk motion artifacts can extend TE and limit SNR. We have developed a Convex Optimized Diffusion Encoding (CODE) framework to design time-optimal, motion compensated diffusion encoding gradients that remove sequence dead times and minimize TE. CODE gradients were designed and implemented for cardiac DWI on a 3.0T clinical scanner in healthy volunteers and patients. CODE reduced bulk motion artifacts compared with conventional monopolar encoding.

Benoit Scherrer¹, Amara Majeed², Onur Afacan¹, Jolene M. Singh¹, Simon K. Warfield¹, and Stephen P. Sanders^2
1Department of Radiology, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States, ²Departments of Cardiology and Pathology, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States

While the left ventricle (LV) myofiber architecture has been studied extensively, there have been fewer studies of right ventricle (RV) myofiber architecture, and there is no established convention for reporting RV myofiber anatomy. Establishing the normal RV myofiber architecture is critical to facilitate our understanding of the impact of congenital microstructural defects in diseased hearts. In this work, we fixed a juvenile swine heart and imaged it with magnetic resonance diffusion compartment imaging (MR-DCI). We describe the detailed myofiber pattern of the RV with both MR-DCI and stained histological microscopy, and propose a standardized convention for describing the myofiber anatomy.

Constantin von Deuster^1,2, Eva Sammut¹, Christian T. Stoeck^1,2, Reza Razavi¹, and Sebastian Kozerke^1,2
1Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom, ²Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland

In vivo cardiac diffusion tensor imaging (DTI) was employed to study dynamic alterations of myocardial microstructure in patients with dilated cardiomyopathy (DCM) relative to healthy controls using dual-phase cardiac DTI. A reduction in dynamic change of fiber orientation between diastole and systole compared to the controls was observed. Steeper diastolic helix angles in DCM patients relative to controls were associated with a larger pre-stretch of the left ventricle. It is speculated that this larger pre-stretch alongside with reduced myocyte shortening compromises the ability to dynamically reorient fiber aggregates during systolic contraction.

Darryl McClymont¹, Irvin Teh¹, Hannah Whittington¹, Vicente Grau², and Jurgen Schneider^1
1Division of Cardiovascular Medicine, University of Oxford, Oxford, United Kingdom, ²Department of Engineering Science, University of Oxford, Oxford, United Kingdom

Non-Gaussian diffusion MRI allows the quantification of diffusion signals that deviate from mono-exponential decay. In cardiac MRI, very little has been reported on non-Gaussian models. In this work, the diffusion tensor, stretched exponential, bi-exponential, and diffusion kurtosis models were fit to data from fixed rat hearts. Performance was measured using the Akaike Information Criterion (AIC). All models demonstrated the presence of non-Gaussian diffusion, particularly in the right ventricle. The bi-exponential model fit the data best and had the lowest AIC. Non-Gaussian diffusion was greater perpendicular, rather than parallel, to cardiac fibers, corresponding to greater restrictions to diffusion.

Kévin Moulin^1,2, Alban Chazot³, Pierre Croisille^1,3, and Magalie Viallon^1,3
1CREATIS, Université de Lyon ; CNRS UMR5220 ; Inserm U1044 ; INSA-Lyon ; Université Claude Bernard Lyon 1, Lyon, France, ²Siemens Healthcare France, Paris, France, ³Department of Radiology, Centre Hospitalier Universitaire de Saint- Etienne, Université Jean-Monnet, Saint-Etienne, France

DW-CMR remains challenging due to respiratory and heart motion. Recent developments in cardiac diffusion imaging proposed Acceleration Motion Compensation (AMC) spin echoes encoding scheme to tackle cardiac motion. In addition, free breathing acquisition with prospective motion correction like slice following technique has been shown to reduce efficiently and significantly the scan time. Here, we proposed a method to quantify the remaining cardiac or breathing motion corruption in DW-CMR measurement and we evaluated it using 3 diffusion encoding scheme: AMC, Stjekal-Tanner and Twice Refocused Spin Echo. Error maps were also compared to physiological motion indicators: cardiac motion using strain measurement and breathing phase using navigator information.

Tamer Mohamed¹, Yu Huang¹, Maythem Saeed², Deepark Srivastava¹, and Sergey Magnitsky^3
1Gladstone Institute, San Francisco, CA, United States, ²UCSF, San Francisco, CA, United States, ³Radiology, UCSF, San Francisco, CA, United States

In this study we compared two in vivo imaging techniques to obtain anatomical and physiological parameters of mice hart. Our results suggest that measurements of enjection fraction and mass of left ventricle were easier and cheaper with ultrasound echocardiography however evaluation of a scar tissue and re-muscularization of infarcted myocardium are only possible with MRI method

Austin James Taylor¹, Zion Tse¹, Ehud Schmidt², Matthew Miller¹, Mable Fok¹, and Kent Nilsson^3
1Engineering, The University of Georgia, Athens, GA, United States, ²Department of Radiology, Brigham and Women's Hospital, Boston, MA, United States, ³Medicine, The University of Georgia, Athens, GA, United States

Catheter ablation is a common electrophysiological (EP) procedure to treat irregular heart rhythm conditions, such as atrial fibrillation.  Catheter ablation can be assisted through the use of imaging coils under magnetic resonance imaging (MRI) which provides a roadmap for preoperative preparation and intraoperative catheter navigation. Intra-cardiac imaging coils allow for ablated lesions to be observed in real time with excellent soft tissue contrast, providing electrophysiologists better control over the result of the procedure.  We present a novel catheter design which integrates a unique origami deployable mechanism for enabling parallel MR imaging in MRI guided  EP procedures.

Andrew David Scott^1,2, Upasana Tayal^1,2, Sonia Nielles-Vallespin^1,3, Pedro Ferreira^1,2, Xiaodong Zhong⁴, Frederick Epstein⁵, Sanjay Prasad^1,2, and David Firmin^1,2
1NIHR funded Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, United Kingdom, ²National Heart and Lung Institute, Imperial College London, London, United Kingdom,³National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD, United States, ⁴MR R&D Collaborations, Siemens Healthcare, Atlanta, GA, United States, ⁵University of Virginia, Department of Biomedical Engineering, Charlottesville, VA, United States

Displacement encoding with stimulated echoes (DENSE) can provide valuable strain information, but acquisitions are typically too long for patient cohorts who have difficulty breath holding. In this work we accelerate 2D cine spiral DENSE acquisitions by selectively exciting a small field of view around the heart. We compare strain data derived from DENSE acquired with unaccelerated and up to 2.5x acceleration in a cohort of healthy subjects and show minimal differences when the acquisition is accelerated. We also show an example from a patient with a myocardial infarction where the accelerated DENSE data shows abnormal strain in the infarcted regions.

Jonathan D Suever^1,2, Gregory J Wehner³, Christopher M Haggerty^1,2, Linyuan Jing^1,2, David K Powell³, Sean M Hamlet⁴, Jonathan D Grabau², Dimitri Mojsejenko², and Brandon K Fornwalt^1,2,3
1Institute for Advanced Application, Geisinger Health System, Danville, PA, United States, ²Pediatrics, University of Kentucky, Lexington, KY, United States, ³Biomedical Engineering, University of Kentucky, Lexington, KY, United States, ⁴Electrical Engineering, University of Kentucky, Lexington, KY, United States

Cardiac mechanics have been extensively characterized in the left ventricle (LV). However, the right ventricle (RV) is rarely studied due to both acquisition and post-processing challenges. In this study, we combined 3D displacement-encoded (DENSE) imaging with custom post-processing that utilizes a local coordinate system to extract advanced measures of cardiac mechanics in an effort to characterize healthy biventricular function. We found that torsion as well as circumferential and longitudinal strain vary throughout the RV, but globally were comparable to their LV counterparts. This data can be used to better understand how biventricular function is disrupted by disease.

Abraham Bogachkov¹, Kai Lin², Ahmadreza Ghasemiesfe², Amir Ali Rahsepar³, Bruce Spottiswoode³, Ben Freed⁴, Michael Markl², James Carr², and Jeremy Collins^2
1Northwestern University Feinberg School of Medicine, Chicago, IL, United States, ²Radiology, Northwestern University, Chicago, IL, United States, ³Cardiovascular MR R&D, Siemens Healthcare, Chicago, IL, United States, ⁴Cardiology, Northwestern University, Chicago, IL, United States

Strain imaging at cardiac MR has been shown to be a powerful tool in the pre-clinical detection of early cardiac dysfunction in the heart failure population, but has been only minimally studied in cardiotoxicity patients. This study evaluated a semi-automatic heart deformation analysis (HDA) tool in the assessment of left ventricular myocardial strain in patients with known cardiotoxicity, and found very good to excellent agreement with global strain values calculated using displacement encoding with stimulated echoes (DENSE). HDA analysis of conventional cine sequences has the potential to play a significant role in the evaluation of patients at risk for cardiotoxicity.

Xiaoying Cai¹, Xiao Chen², Yang Yang¹, Michael Salerno³, Daniel S. Weller⁴, Craig H. Meyer¹, and Frederick H. Epstein^1
1Biomedical Engineering, University of Virginia, Charlottesville, VA, United States, ²Medical Imaging Technologies, Siemens Healthcare, Princeton, NJ, United States, ³University of Virginia, Charlottesville, VA, United States, ⁴Electrical and Computer Engineering, University of Virginia, Charlottesville, VA, United States

Current cine DENSE protocols require breath-holding, which limits the use of this technique to patients with good breath-holding capabilities and excludes many pediatric and heart failure patients.  To accomplish free-breathing scans with high efficiency and quality, we developed a 2D cine DENSE acquisition and reconstruction framework that utilizes localized signal generation, image-based self-navigated motion estimation, k-space motion correction and compressed sensing. Reconstructions and Bland-Altman analysis from 5 volunteers demonstrated that the proposed method recovered high-quality images and strain data from free-breathing data, showing better agreement than conventional reconstructions of the same data with breath-holding scans. 

Amol Pednekar¹, Jiming Zhang², Debra Dees³, Benjamin Y Cheong³, and Raja Muthupillai^3
1Phillips Healthcare, Cleveland, OH, United States, ²Diagnostic and interventional Radiology, CHI St Luke's Health, Houston, TX, United States, ³Diagnostic and Interventional Radiology, CHI St Luke's Health, Houston, TX, United States

Diastolic functional indices based on trans-mitral blood flow velocities are pre-load dependent and early diastolic filling can be diminished by activities such as inspiration or Valsalva maneuver.  Cardiac cine MR images are typically acquired during suspended respiration and thus could induce systemic bias. In this study, we evaluate the impact of respiratory suspension on the computation of volume-based diastolic indices using peak velocity-based Doppler echo measurements as the reference. The volume based diastolic indices derived from high temporal resolution cine MR correlated well with velocity based E/A ratio from echo while indicating the direct impact of respiratory suspension.

Jin Yamamura¹, Sarah Keller¹, Roland Fischer^2,3, Regine Grosse⁴, Gregory Kurio³, Gunnar Lund¹, Joachim Graessner⁵, Gerhard Adam¹, and Bjoern Schoennagel^1
1Diagnostic and Interventional Radiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany, ²Biochemistry, University Medical Center Hamburg-Eppendorf, Hamburg, Germany,³Department of Radiology, UCSF Benioff Children's Hospital Oakland, Oakland, CA, United States, ⁴Department of Pediatric Hematology/Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany, ⁵Siemens Healthcare, Hamburg, Germany

The diastolic peak filling rate ratio (PFRR) is a sensitive marker to indicate diastolic dysfunction from myocardial iron toxicity in patients with systemic iron overload disease. Precise assessment of the PFRR by CMR requires a volumetric approach with exclusion of trabeculae and papillary muscles from the LV cavity. The PFRR assessed by CMR may be a valuable parameter for the screening and monitoring of myocardial iron toxicity due to iron deposition in patients with preserved systolic function.

Thomas Kennedy¹, Omid Forouzan², Oliver Wieben^1,3, Naomi C Chesler², Jacob Macdonald³, and Christopher J Francois^1
1Radiology, University of Wisconsin- Madison, Madison, WI, United States, ²Biomedical Engineering, University of Wisconsin- Madison, Madison, WI, United States, ³Medical Physics, University of Wisconsin- Madison, Madison, WI, United States

Dyspnea on exertion is a common manifestation of systolic and diastolic heart failure. Using an MRI-compatible exercise device allowing subjects to exercise while in the bore of the scanner, we assessed exercise-induced changes in diastolic transmitral flow in younger and older healthy volunteers and subjects with pulmonary hypertension. The measurements we obtained demonstrated decreased E/A ratios for older healthy volunteers and PH subjects when compared to younger healthy volunteers, however these differences were not statistically significant. 

Hsin-Jung Yang¹, Damini Dey¹, Jane Sykes², John Butler², Xiaoming Bi³, Behzad Sharif¹, Sotirios Tsaftaris⁴, Debiao Li¹, Piotr Slomka¹, Frank Prato², and Rohan Dharmakumar^1
1Cedars Sinai Medical Center, Los Angeles, CA, United States, ²Lawson Health Research Institute, london, ON, Canada, ³Siemens Healthcare, Los Angeles, CA, United States, ⁴IMT Institute for Advanced Studies Lucca, Lucca, Italy

Current myocardial BOLD MR methods are limited by: (a) poor spatial coverage and imaging speed; (b) imaging confounders; and (c) imaging artifacts, particularly at 3T. To address these limitations, we developed a heart-rate independent, free-breathing 3D T2 mapping technique at 3T that utilizes near 100% imaging efficiency, which can be completed in 3 minutes with full LV coverage. We tested our method in a canine model of coronary stenosis and validated our findings with simultaneously acquired13N-ammonia PET perfusion data in a whole-body PET/MR system.

Marius Menza¹, Daniela Föll², Jürgen Hennig¹, and Bernd Jung^3
1University Medical Center Freiburg, Dept. of Radiology - Medical Physics, Freiburg, Germany, ²University-Heart Center Freiburg, Cardiology und Angiology I, Freiburg, Germany, ³University Hospital Bern, Institute of Diagnostic, Interventional and Pediatric Radiology, Bern, Switzerland

MR Tissue Phase Mapping (TPM) is a powerful approach to assess left ventricular (LV) function. Conventional Cartesian acquisition-strategies with k-t-based parallel imaging acceleration allow the acquisition of a single slice within a breath-hold, but suffer from low spatial resolution. In this work a comparison with undersampled high-resolution spiral SPIRIT TPM for different trajectory designs within one breath-hold and free breathing Cartesian k-t-accelerated PEAK TPM is presented. High image quality, comparable peak velocity values and time to peaks of spiral SPIRIT TPM for high resolution within a breath-hold might enhance myocardial functional analysis.

Elwin Bassett¹, Ganesh Adluru², Brent D. Wilson³, Cory Nitzel³, Tobias Block⁴, Hassan Haji-Valizadeh⁵, Edward VR DiBella², and Daniel Kim^2
1Physics, University of Utah, Salt Lake City, UT, United States, ²Radiology, UCAIR, University of Utah, Salt Lake City, UT, United States, ³Internal Medicine, Division of Cardiology, University of Utah, Salt Lake City, UT, United States, ⁴School of Medicine, Radiology, New York University, New York, NY, United States, ⁵Bioengineering, University of Utah, Salt Lake City, UT, United States

To date, no study has compared 12-fold accelerated real-time cine MRI with compressed sensing (CS) between Cartesian and radial k-space sampling schemes. We sought to compare their performance in patients and volunteers. We compared point spread functions (PSF) to determine which sampling pattern generates more incoherent aliasing artifacts. We also compared their performance in a group of 15 patients and one volunteer, where 3-fold accelerated product real-time MRI was used as reference. Two cardiologists independently graded images from each subject.

PSF analysis showed that radial produces more incoherent aliasing artifacts. Image quality was better for radial than Cartesian sampling schemes. 

KyungPyo Hong^1,2 and Daniel Kim^1
1Radiology, UCAIR, University of Utah, Salt Lake City, UT, United States, ²Bioengineering, University of Utah, Salt Lake City, UT, United States

Patients with end-stage heart failure (HF) often require advanced therapeutics, but current clinical profiles and biomarkers are not adequate for predicting outcomes. Myocardial perfusion reserve may be an important predictor, but it is technically challenging to perform perfusion MRI in patients with end-stage HF because they often have implantable cardioverter defibrillator (ICD), which generates significant image artifacts. We developed a novel cardiac perfusion pulse sequence using a wideband saturation pulse. Compared with standard perfusion MRI, wideband perfusion MRI suppresses image artifacts induced by ICD.      

Yoshiaki Morita¹, Naoaki Yamada¹, Makoto Amaki², Emi Tateishi², Asuka Yamamoto², Masahiro Higashi¹, and Hiroaki Naito^1
1Department of Radiology, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan, ²Division of Cardiology, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan

Right ventricular (RV) function has a significant impact on the prognosis of chronic thromboembolic pulmonary hypertension (CTEPH), as it does with other forms of pulmonary arterial hypertension (PH). In this study, we demonstrated that feature tracking imaging (FTI) is fast, simple, and has potential for clinical use for assessing RV strain in CTEPH. The global longitudinal strain (GLS) showed better correlation with the RV ejection fraction (RVEF) and mean pulmonary artery pressure (mPAP). FTI-derived strain measurement might offer a modality for good detection of RV dysfunction and repeatable monitoring after therapeutic intervention.

Thomas Kennedy¹, Niti Aggarwal², Christopher Francois¹, Mark Schiebler¹, and Jeremy Collins^3
1Radiology, University of Wisconsin- Madison, Madison, WI, United States, ²Cardiology, Univesity of Wisconsin-Madison, Madison, WI, United States, ³Radiology, Northwestern University, Chicago, IL, United States

Diastolic dysfunction is the primary cause of CHF in 40-60% of patients with heart failure in the United States and has been shown to lead to poor outcomes.  Early diagnosis and treatment of the causes of diastolic dysfunction is effective in relieving symptoms and reducing mortality. The non- invasive methods which can be used to assess diastolic function include cardiac magnetic resonance (CMR) imaging. The purpose of this educational poster is to describe the CMR techniques which can be used to evaluate diastolic function and review the CMR findings of this disorder.

Martin Genet^1,2, Christian T Stoeck^3,4, Constantin von Deuster^3,4, Lik Chuan Lee⁵, Julius M Guccione⁶, and Sebastian Kozerke^3,4
1École Polytechnique, Palaiseau, France, ²Institute for Biomedical Engineering, ETHZ, Zurich, Switzerland, ³KCL, London, United Kingdom, ⁴ETHZ, Zurich, Switzerland, ⁵MSU, East Lansing, MI, United States, ⁶UCSF, San Francisco, CA, United States

The objective of the present work was to develop, validate and analyze a finite element digital image correlation approach of extracting ventricular strain data from MR images, which can be applied to both 3D CSPAMM images and conventional multi-slice cine images. Cine and 3D CSPAMM data was acquired on a normal human volunteer, and analyzed. The proposed method provided similar circumferential strain data compared to already validated SinMod method. In contrast to strain mapping from cine images, strain mapping from 3D CSPAMM images captures ventricular twist and torsion in agreement with physiological values, and is less sensitive to image misregistration.

Freddy Odille^1,2,3, Lin Zhang^1,2, Bailiang Chen^1,2,3, Jacques Felblinger^1,2,3,4,5, Damien Mandry^1,2,4, and Marine Beaumont^3,5
1U947, Inserm, Nancy, France, ²IADI, Université de Lorraine, Nancy, France, ³CIC-IT 1433, Inserm, Nancy, France, ⁴Pôle imagerie, CHRU de Nancy, Nancy, France, ⁵Pôle S2R, CHRU de Nancy, Nancy, France

A data analysis framework is proposed to study the relation between scar severity and regional myocardial function during the process of remodeling after acute myocardial infarction (MI). The framework includes registration steps to correct for slice-to-slice inconsistencies, to align cine with late gadolinium enhancement (LGE) data and to align data from follow-up scans. The framework was evaluated in 114 patients with CMR scans within 3 days after MI and at 6 months. Registration accuracy was below 3 mm. Results show that function at 6 months was inversely associated with scar transmuraltiy at both 3 days and 6 months.

Mahon L Maguire¹, Mala Rohling², Megan Masters², Debra McAndrew¹, Paul Riley², and Jurgen E Schneider^1
1Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom, ²Department of Physiology, Anatomy, and Genetics, University of Oxford, Oxford, United Kingdom

The neonatal mouse heart has been reported to regenerate following myocardial injury during the first days of life. Research into this regenerative capability is being actively pursued for translation into the clinic.  This study presents cardiac cine imaging of one-day old mice using retrospectively gated, accelerated MR imaging with recovery.   Images were acquired with 78x78x500 μm resolution.  Left ventricular functional parameters were derived from the images and are presented.  This proof of concept study demonstrates that cardiac functional MR imaging with recovery in newborn mice is practical.  It also allows the investigation of myocardial regeneration during the first days of life.

Fabian Tobias Gutjahr¹, Thomas Kampf¹, Stephan Michael Guenster¹, Volker Herold¹, Patrick Winter¹, Xavier Helluy², Wolfgang Bauer³, and Peter Jakob^1
1Experimental Physics V, University of Wuerzburg, Wuerzburg, Germany, ²NeuroImaging Centre, Ruhr University, Bochum, Germany, ³Department of Internal Medicine 1, Universitaetsklinikum Würzburg, Wuerzburg, Germany

A fast method for the measurement of myocardial perfusion in mice is presented. Using an efficient retrospective data selection and weighting process in combination with a model based reconstruction perfusion maps can be acquired within 3.5min.

Anna Mou¹, Zhiyong Li¹, Mengying Li², Qingwei Song², Chen Zhang², and Ailian Liu^2
1Radiology, The First Affiliated Hospital of Dalian Medical University, Dalian, China, People's Republic of, ²Dalian, China, People's Republic of

Myocardial microcirculation perfusion dysfunction plays an important role in assessment cardiac disease especially diabetes and hypertension because of their high incidence in the world. We preliminarily investigated the difference of myocardial micro-vascular perfusion between patients with diabetes/hypertension and normal volunteers with IVIM (0, 20, 50, 80, 120, 150, 200, 300, 500 s/mm2) diffusion weighted imaging. We found that Fast _ADC values in patients were significant lower than in healthy volunteers. We concluded that IVIM CMR could quantitatively and noninvasively evaluate perfusion status in patients with diabetes and/or hypertension.

Regine Schmidt¹, Hanns-Christian Breit¹, and Laura Maria Schreiber^1,2
1Section of Medical Physics, Department of Radiology, Johannes Gutenberg University Medical Center, Mainz, Germany, ²Department of Cellular and Molecular Imaging, Comprehensive Heart Failure Center (CHFC), Wuerzburg, Germany

The dispersion of the contrast agent bolus at T1-weighted contrast-enhanced first-pass myocardial perfusion MRI was examined by means of computational fluid dynamics simulations. In this study simulations in idealized coronary artery geometries with different extent of vessel tortuosity and in a straight reference vessel geometry have been performed for the condition of rest and stress. The contrast agent bolus dispersion was larger at rest compared to stress. Furthermore, a negative correlation between the extent of tortuosity and the contrast agent bolus dispersion was found.

Hung Phi Do¹ and Krishna S Nayak^2
1Department of Physics and Astronomy, University of Southern California, Los Angeles, CA, United States, ²Ming Hsieh Department of Electrical Engineering, University of Southern California, Los Angeles, CA, United States

Modi?ed Look-Locker Inversion Recovery (MOLLI) provides the highest precision and reproducibility for myocardial T₁ mapping, and extracellular volume (ECV) mapping. In this work, we determine its effectiveness for measuring myocardial blood flow (MBF), based on apparent-T₁ mapping under two conditions, slice-selective inversion and non-selective inversion. We demonstrate that MOLLI provides measured MBF comparable to the reference FAIR-SSFP ASL method.

Ganesh Adluru¹, Chris Welsh¹, John Roberts¹, and Edward DiBella^1
1Radiology, University of Utah, Salt Lake City, UT, United States

High-resolution myocardial perfusion imaging offers improved delineation of subendocardial ischemic regions and can lead to improved diagnosis.  Here we use undersampled radial simultaneous multi-slice (SMS) acquisitions in conjunction with constrained reconstruction with temporal total variation and spatial block-matching 3D (BM3D) constraints to obtain high in-plane spatial resolution perfusion imaging.  Promising results are shown with two types of myocardial perfusion acquisitions (i) a set of 3 simultaneous slices after a saturation pulse, repeated several times per beat at different cardiac phases, and (ii) a ‘hybrid’ perfusion acquisition with one saturation pulse per beat and the reconstructed cardiac phase of the 3 slices chosen retrospectively.

Merlin J Fair^1,2, Peter D Gatehouse^1,2, Liyong Chen^3,4, Ricardo Wage², Edward VR DiBella⁵, and David N Firmin^1,2
1NHLI, Imperial College London, London, United Kingdom, ²NIHR Cardiovascular BRU, Royal Brompton Hospital, London, United Kingdom, ³UC Berkeley, Berkeley, CA, United States, ⁴Advanced MRI Technologies, Sebastopol, CA, United States, ⁵UCAIR, University of Utah, Salt Lake City, UT, United States

A method for enabling a balanced steady-state free precession 3D stack-of-stars approach to whole-heart first-pass myocardial perfusion imaging is investigated. Consideration is made of the impact of potential off-resonance effects at 3T and sequence-based modifications to rectify this are examined. Demonstration of the feasibility of this approach is then performed in-vivo.

Hung Phi Do¹, Andrew J Yoon², Michael W Fong², Farhood Saremi³, Mark L Barr⁴, and Krishna S Nayak^5
1Department of Physics and Astronomy, University of Southern California, Los Angeles, CA, United States, ²Department of Medicine, Divison of Cardiology, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA, United States, ³Department of Radiology, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA, United States, ⁴Department of Cardiothoracic Surgery, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA, United States, ⁵Ming Hsieh Department of Electrical Engineering, University of Southern California, Los Angeles, CA, United States

Double-gating in myocardial ASL allows for variations in the post-labeling delay in order to ensure that both labeling and imaging occur in the same cardiac phase. Originally proposed by Poncelet et al. in 1999, this was believed to provide insensitivity to heart rate variation. Despite this, most groups have utilized single-gating with a fixed post-labeling delay for pairs of control and tagged images, since this allows for simpler quantification of myocardial blood flow. In this study, we demonstrate that the double-gating is indeed more robust to heart rate variation compared to single-gating for myocardial ASL, based on experiments in healthy volunteers and heart transplant recipients.

Terrence Jao¹ and Krishna Nayak^2
1Biomedical Engineering, University of Southern California, Los Angeles, CA, United States, ²Electrical Engineering, University of Southern California, Los Angeles, CA, United States

Arterial spin labeled CMR is a non-contrast myocardial perfusion imaging technique capable of assessing coronary artery disease. A limitation of current methods is potential underestimation of blood flow to myocardial segments that have coronary arterial transit time longer than 1 R-R, which are found in regions with significant collateral development from chronic myocardial ischemia. In this work, we demonstrate the feasibility of a velocity selective labeling scheme for ASL-CMR that is insensitive to arterial transit time.

Marshall Stephen Sussman^1,2 and Bernd Juergen Wintersperger^1,2
1Medical Imaging, University Health Network, Toronto, ON, Canada, ²Medical Imaging, University of Toronto, Toronto, ON, Canada

    The MOLLI $$$T_1$$$ mapping technique has been used to characterize a variety of cardiac pathologies.  However, a significant limitation of this technique is the requirement for rest periods between inversion groups.  This increases scan time, and limits the choice of possible inversion groups.  A new technique, inversion group (IG) MOLLI fitting, has been recently shown to eliminate the requirement for rest periods, and permits complete flexibility of inversion group selection.  However, a significant limitation of this technique is that the resulting $$$T_1$$$ maps have low precision.  In this study, a method is presented for high precision IG fitting.  

Nadja M Meßner^1,2, Sebastian Weingärtner^1,3,4, Johannes Budjan⁵, Dirk Loßnitzer⁶, Theano Papavassiliu^2,6, Lothar R Schad¹, and Frank G Zöllner^1
1Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany, ²DZHK (German Centre for Cardiovascular Research) partner site Mannheim, Mannheim, Germany, ³Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, United States, ⁴Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States, ⁵Institute of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany, ⁶1st Department of Medicine Cardiology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany

Partial volume artifacts in myocardial T₁-mapping are a major source of quantification inaccuracy. In this study, saturation-recovery T₁-mapping at 3T was adapted to allow for systolic imaging in order to take advantage of the increased myocardial wall thickness. Estimated T₁- and ECV- values for SR T₁-mapping during systole were 1554±3ms/0.29±0.03 compared to 1581±35ms/0.31±0.04 at diastole. In conclusion, our results show that SR T₁-mapping in systole might be an alternative to derive T₁- and ECV-values with reduced effects of partial volume.

Jaime L. Shaw^1,2, Anthony G. Christodoulou^1,3, Behzad Sharif¹, and Debiao Li^1,2
1Biomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States, ²Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, United States,³Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States

Current cardiac T1 mapping techniques are generally limited to single-shot 2D images acquired in a breath hold with ECG gating. Heart rate variability or poor ECG triggering are sources of error and reduced reproducibility in the widely used MOLLI T1 mapping technique. To mitigate the dependence of T1 mapping on heart rate and breath-holds, we propose an ungated, free-breathing, continuous IR approach using low-rank tensors modeling the image as partially separable in space, cardiac phase, respiratory phase, and inversion time. We show the feasibility of the ungated, free-breathing approach in producing T1 maps in multiple cardiac phases in under 1 minute.

Tori A Stromp^1,2, Joshua C Kaine^2,3, Tyler J Spear², Kristin N Andres^2,3, Brandon K Fornwalt⁴, Vincent L Sorrell⁵, Steve W Leung⁵, and Moriel H Vandsburger^1,2,6
1Department of Physiology, University of Kentucky, Lexington, KY, United States, ²Saha Cardiovascular Research Center, University of Kentucky, Lexington, KY, United States, ³College of Medicine, University of Kentucky, Lexington, KY, United States, ⁴Institute for Advanced Application, Geisinger Health System, Danville, PA, United States, ⁵Gill Heart Institue, University of Kentucky, Lexington, KY, United States, ⁶Biomedical Engineering, University of Kentucky, Lexington, KY, United States

Patients with end stage renal disease (ESRD) suffer from high rates of sudden cardiac death, often attributed to development of reactive fibrosis.  This study aims to integrate cardiac tissue characterization via non-contrast 2-pt bSSFP with myocardial mechanical analysis. ESRD patients demonstrate elevated myocardial signal with magnetization transfer-weighted 2-pt bSSFP, indicating increased fibrosis. This elevated signal correlates with delayed time to peak contraction and septo-lateral dyssynchrony, which are both elevated in ESRD patients. Combining non-contrast 2-pt bSSFP for tissue characterization with analysis of regional contractile function offers a promising approach to identify potential MRI biomarkers of cardiac risk in ESRD.

Rui Guo¹, Zhensen Chen¹, Jianwen Luo¹, and Haiyan Ding^1
1Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China, People's Republic of

In this study, we developed a free-breathing, three-dimensional (3D) T1 mapping method at 3T based on the saturation-prepared, inversion-prepared radiofrequency-spoiled gradient echo (SPGR) sequence, which achieved 3D T1 maps with whole heart coverage. Excellent correlation for the T1 values typically observed in myocardium pre and post contrast was obtained with little residual (R² = 0.99) and a regression slope 0.93. Homogeneous T1 maps were obtained from in-vivo study. Whole left ventricle T1 mapping was finished in around ~10 minutes with about 40% navigator efficiency without using any parallel imaging. Measured normal myocardium T1 values were comparable to those previously published.

Nadja M Meßner^1,2, Sebastian Weingärtner^1,3,4, Johannes Budjan⁵, Dirk Loßnitzer⁶, Uwe Mattler⁵, Theano Papavassiliu^2,6, Lothar R Schad¹, and Frank G Zöllner^1
1Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany, ²DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Germany, ³Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, United States, ⁴Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States, ⁵Institute of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany, ⁶1st Department of Medicine Cardiology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany

Myocardial T₁- and ECV-mapping for the detection of fibrosis is commonly performed at 1.5T with inversion-recovery (IR) techniques such as MOLLI.

As an alternative, we studied the robustness and precision of the saturation-recovery (SR) T₁-mapping techniques SAPPHIRE and SASHA at 3T in 20 healthy volunteers. The resulting T₁- and ECV- reference values for SR T₁-mapping were 1578±42ms/0.30±0.03 (SAPPHIRE) and 1523±46ms/0.31±0.03 (SASHA), revealing the underestimation of T₁-times by MOLLI to be approximately 20-29%.

Therefore, we suggest SR T₁-mapping with its high accuracy, low precision-loss, and good inter-subject variability as a valuable alternative to IR T₁-mapping at 3T.

Kelvin Chow¹, Yang Yang², and Michael Salerno^1,2
1Medicine, Division of Cardiology, University of Virginia, Charlottesville, VA, United States, ²Biomedical Engineering, University of Virginia, Charlottesville, VA, United States

The robustness of SASHA T1 mapping to systematic errors provides more accurate T1 measurements, but SASHA is less precise than the more commonly used MOLLI sequence.  Free-breathing SASHA acquisitions can increase precision in T1 maps, but motion correction of SASHA images is challenging due to poor blood-tissue contrast.  We present a novel approach for robust image registration by acquiring additional high-contrast data in a keyhole fashion without affecting T1 accuracy.  In 10 healthy subjects, a SASHA T1 maps acquired in <90 seconds of free-breathing had a lower myocardial T1 standard deviation than MOLLI (46.1±3.8 ms vs. 55.3±7.7 ms, p<0.05).

Jiayu Sun¹, Simeng Wang¹, Robert O'Connor², David Muccigrosso³, Yucheng Chen⁴, Wei Cheng¹, Charles Hildebolt³, Fabao Gao¹, and Jie Zheng^3
1Radiology, West Hospital, Chengdu, China, People's Republic of, ²NIH, Bethesda, MD, United States, ³Radiology, Washington University in St. Louis, St. Louis, MO, United States, ⁴Cardiology, West Hospital, Chengdu, China, People's Republic of

The purpose is to develop and evaluate a non-contrast CMR approach for sensitive and quantitative assessment of myocardial fibrosis. Ten patients with cardiomyopathy were scanned with and without contrast injection. A quantitative fibrosis index derived from native T1ρ dispersion contrast was obtained and compared with extracellular volume calculated by T1 mapping. A strong correlation was shown between two indexes and superior sensitivity was observed for fibrosis index to detect myocardial diffuse fibrosis.

Martin A Janich¹, Steven D Wolff², Oleg Shubayev², and Anja CS Brau^3
1GE Global Research, Munich, Germany, ²Advanced Cardiovascular Imaging, New York, NY, United States, ³GE Healthcare, Munich, Germany

Late Gadolinium Enhancement (LGE) with fat suppression typically leaves traces of fat signal in the image. The goal of the present work is to completely remove fat signal from the LGE image and to visualize fat separately. The PiSCES method applies phase sensitive image reconstruction and customized timing of fat-selective RF pulses. In 19 out of 22 patient examinations PiSCES better removed fat compared to conventional magnitude fat-suppressed LGE.

Chiao-Ning Chen¹, Hsiao-Hui Huang¹, Ming-Ting Wu², and Teng-Yi Huang^1
1Electrical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan, ²Radiology, Kao-Hsiung Veterans General Hospital, Kao-Hsiung, Taiwan

This study attempted to improve the accuracy of T1 fitting and image registration for automatic extracellular volume fraction mapping. We proposed to use multiple initial values in the T1 fitting procedure and the results prominently exhibited less errors. For the image registration, we first performed the automatic segmentation of left-ventricle (LV) walls based on an image synthesis approach and then used the obtained LV masks for the deformable image registration. The results supported that the method significantly improved the overlap rate between the pre- and postcontrast images as well as the accuracies of the obtained ECV maps.

Laura Claire Saunders¹, Neil J Stewart¹, Charlotte Hammerton¹, David Capener¹, Valentina O Puntmann², David G Kiely³, Martin J Graves⁴, Andy Swift¹, Jim M Wild¹, and Laura Claire Saunders^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 pulmonary hypertension (n=102, 58±16 years, 56% female) and age and sex matched volunteers (n=34, 51±14 years, 58% female) underwent functional cardiac MR and MOLLI T1 mapping at 1.5T. MOLLI images were registered to correct for respiratory motion. Patients had elevated myocardial T1 at the right ventricular (RV) insertion point (p<0.001) and left ventricular free wall when compared to healthy volunteers (p=0.013). RV insertion point T1 and pulmonary artery pressure correlated significantly (r=0.406 p=0.016). Correlations were found between RV free wall and septal T1 and diastolic mass index (corrected for age and sex) (r=0.305, p=0.003 and r=0.281, p=0.006 respectively). Patients with pulmonary hypertension (n=102, 58±16 years, 56% female) and age and sex matched volunteers (n=34, 51±14 years, 58% female) underwent functional cardiac MR and MOLLI T1 mapping at 1.5T. MOLLI images were registered to correct for respiratory motion. Patients had elevated myocardial T1 at the right ventricular (RV) insertion point (p<0.001) and left ventricular free wall when compared to healthy volunteers (p=0.013). RV insertion point T1 and pulmonary artery pressure correlated significantly (r=0.406 p=0.016). Correlations were found between RV free wall and septal T1 and RV mass index (corrected for age and sex) (r=0.305, p=0.003 and r=0.281, p=0.006 respectively).

Hongmei Zhou¹, Xue Lin¹, Haiyan Ding², and Quan Fang^1
1Cardiology, Peking Union Medical College, Beijing, China, People's Republic of, ²Center for Biomedical Imaging Research, Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing, China, People's Republic of

Left Ventricular Non-compaction (LVNC) manifesting with myocardial fibrosis can cause cardiac dysfunction, arrhythmia, and sudden death. Native T1 mapping is an emerging CMR technique in quantitative evaluation of myocardial fibrosis. This study aimes to investigate the usefulness of native T1 mapping in characterization of myocardial abnormalities in LVNC patients by comparing with late gadolinium enhancement. It may suggest that native T1 mapping may provide information for early detection of fibrosis in compacted myocardium and stratification of severity in Left Ventricular Non-compaction.

Zhaohuan Zhang^1,2, Eric Aliotta^2,3, and Daniel B Ennis^2,3
1Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, China, People's Republic of, ²Department of Radiological Sciences, University of California, Los Angeles, CA, United States, ³Physics & Biology in Medicine Graduate Program, University of California, Los Angeles, CA, United States

 Myocardial T₂ and Apparent Diffusion Coefficient (ADC) can be used to evaluate the presence of edema and myocardial infarction^1,2. We recently developed a technique for joint acquisition and reconstruction of T₂ and ADC maps using a spin-echo EPI diffusion weighted sequence (SE-EPI DWI) with a total acquisition time short enough to accommodate measurement in a single breath-hold. The objective of this study was to optimize the joint T₂/ADC acquisition to enhance sensitivity to myocardial infarction and to evaluate performance in simulations and phantom experiments.

Junmin Liu¹, James W Goldfarb², and Maria Drangova^1,3
1Imaging Research Laboratories, Robarts Research Institute, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada, ²Department of Research and Education, Saint Francis Hospital, Roslyn, NY, United States, ³Medical Biophysics, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada

Local Frequency Shift (LFS) mapping of the myocardium may provide information about the integrity and organization of myofibers, which contribute anisotropic magnetic susceptibility. We present a myocardial LFS mapping method by explicitly removing the unwanted phase terms caused by B0 inhomogeneity and chemical-shift (CS) between fat and water.  The proposed method was tested with human data and compared with the established high-pass filtering technique.  The results demonstrate a gradient across the myocardial wall suggesting that LFS maps of the myocardium may enable visualization of myofiber orientation. 

Till Huelnhagen¹, Teresa Serradas Duarte¹, Fabian Hezel¹, Erdmann Seeliger², Bert Flemming², Marcel Prothmann³, Jeanette Schulz-Menger³, and Thoralf Niendorf^1,4
1Berlin Ultrahigh Field Facility (B.U.F.F), Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin, Germany, ²Institute for Physiology, Charité University Medicine, Berlin, Germany, ³Working Group on Cardiovascular Magnetic Resonance, Experimental and Clinical Research Center, a joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany, ⁴Experimental and Clinical Research Center, a joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicince in the Helmholtz Association, Berlin, Germany

This work examines the relationship of ventricular septal wall thickness and T₂* at 7.0T in healthy volunteers. Results show, that T₂^* changes periodically over the cardiac cycle, increasing in systole and decreasing in diastole. A strong correlation between mean septal T₂^* and wall thickness was found. Temporally resolved field mapping showed that macroscopic magnetic field fluctuations can be excluded as source of the observed changes. While T₂^* is often regarded as surrogate for tissue oxygenation, the found systolic increase of T₂^* cannot be explained by increased oxygenation. Instead changes in blood volume fraction are assumed to be responsible for the observed T₂^* fluctuations.

Yan Yi¹, Lu Lin¹, Yining Wang¹, Jian Cao¹, Lingyan Kong¹, Jing An², Tianjing Zhang², and Bruce Spottiswoode^3
1Peking Union Medical College Hospital, Beijing, China, People's Republic of, ²Siemens Shenzhen Magnetic Resonance Ltd., beijing, China., Beijing, China, People's Republic of, ³MR Research and Development, Siemens Healthcare, Chigago, IL, United States

The study aim was to explore the diagnostic value of ECV for cardiac amyloidosis calculated by 5 min post-contrast T1-mapping compared with conventional 15-20 min post-contrast T1 mapping. The results showed ECV calculated by 5min post-contrast T1 mapping had similarly promising diagnosis value for cardiac amyloidosis compared with 15-20 min post-contrast T1 mapping.

Joao Luis Tourais¹, Markus Henningsson¹, and Rene Botnar^1
1King's College London, London, United Kingdom

Image navigator based free-breathing whole heart 3D T2prep-based T2 mapping achieved similar accuracy to a conventional 2D-BH T2prep-based mapping approach, and can be performed within less than 5 minutes. With this approach the limitations of conventional 2D T2 mapping (low resolution, mis-registration and diaphragmatic motion between BH) as well as 3D T2 mapping (unpredictable scan time because of navigator gating) have been overcome. These promising results warrant further investigation in patients with myocardial pathologies.

Tobias Wech¹, Nicole Seiberlich², Andreas Schindele³, Alfio Borzì³, Herbert Köstler¹, and Jürgen E. Schneider^4
1Department of Diagnostical and Interventional Radiology, University of Würzburg, Würzburg, Germany, ²Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, ³Institute of Mathematics, University of Würzburg, Würzburg, Germany, ⁴Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom

The feasibility of using real-time MRI to determine $$$T_1$$$ relaxation times in mouse hearts was explored. An inversion recovery prepared and highly undersampled radial acquisition was applied and data were reconstructed using a combination of through-time radial GRAPPA and compressed sensing. The ECG in combination with the DC-signal recorded for each projection was used to eliminate cardiac and respiratory motion, which allowed for fitting $$$T_1$$$-values in every voxel. The method was applied to five mice in vivo and the measured $$$T_1$$$-values found for myocardial tissue agreed well with literature. Our work indicates that it is possible to accurately measure $$$T_1$$$ in mice using real-time MRI.

Xiaoyong Zhang^1,2, Guoxi Xie², Zijun Wei², Yanchun Zhu², Shi Su², Caiyun Shi², Fei Yan², Bensheng Qiu¹, Xin Liu², Hairong Zheng², and Zhaoyang Fan^3
1University of Science and Technology of China, Hefei, China, People's Republic of, ²Shenzhen Institutes of Advanced Technology, Shenzhen, China, People's Republic of, ³Cedars-Sinai Medical Center, Los Angeles, CA, United States

A 3D self-gating technique was developed for assessing mycardial infarction (MI) in mouse model. The preliminary in vivo study has demonstrated that the technique can correctly detect the MI, which may outperform the conventional MR techniques with ECG-triggering and respiratory gating.

Geeshath Jayasekera¹, Colin Church¹, Martin Johnson¹, Andrew Peacock¹, and Aleksandra Radjenovic^2
1Scottish Pulmonary Vascular Unit, Golden Jubilee National Hospital, Glasgow, United Kingdom, ²Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom

Pulmonary hypertension is a rare progressive disorder characterised by elevated pulmonary artery pressure leading to right ventricular failure and death. Native T1 mapping is a CMR technique for myocardial tissue characterisation that does not require MRI contrast administration1. We investigated whether native T1 values relate to invasive pressure measurements and markers of RV dysfunction in patients with pulmonary hypertension. 

Julie Magat¹, Arnaud Fouillet¹, Jérôme Naulin¹, David Benoist¹, Yunbo Guo¹, Olivier Bernus¹, Bruno Stuyvers¹, and Bruno Quesson^1
1IHU LIRYC, Université de Bordeaux, Pessac, France

The motivation of this study was to investigate Magnetization Transfer MRI as a technique of contrast for visualization of the Purkinje Fiber (PF) network in ex vivo cardiac sample of a large animal. We first optimized MT parameters to obtain the best contrast: offset frequency, duration of the module and radiofrequency field. We performed 2D and 3D acquisition on pig ex vivo heart. We were able to enhance contrast between PF network and muscle and visualize insert points inside the myocardium in 3D.

 

Patrick Winter¹, Thomas Kampf¹, Fabian Tobias Gutjahr¹, Cord Bastian Meyer¹, Volker Herold¹, Wolfgang Rudolf Bauer², and Peter Michael Jakob^1
1Experimental Physics 5, University of Wuerzburg, Wuerzburg, Germany, ²Medizinische Klinik und Poliklinik I des Universitaetsklinikums Wuerzburg, Wuerzburg, Germany

Radial trajectories enable self-navigated cardiac T₁ measurements without the necessity of external ECG signals. However, the extracted cardiac synchronization signals and the reconstructed images can be suspectible to B₀ inhomogeneities and flow. In order to improve the robustness of the self-navigated method a 2D - UTE inversion recovery sequence is introduced that minimizes the echo time to 0.57 ms and reduces the susceptibility to B₀ inhomogeneities. Steady state cines and a T₁ map were derived from the UTE measurement. Comparisons with a self-navigated gradient echo measurement indicate more reliable self-navigation signals and better image quality when using shorter echo times.

Shams Rashid¹, Jiaxin Shao¹, and Peng Hu^1,2
1Radiological Sciences, University of California, Los Angeles, Los Angeles, CA, United States, ²Biomedical Physics Inter-Departmental Graduate Program, University of California, Los Angeles, Los Angeles, CA, United States

We present a wideband inversion pulse of 8kHz bandwidth designed with a hyperbolic secant 4 (HS4) adiabatic inversion pulse, for use in wideband late gadolinium enhancement (LGE) MRI in patients with implantable cardioverter-defibrillators (ICDs). This HS4 wideband pulse has more than twice the bandwidth of the previously reported wideband hyperbolic secant (HS) adiabatic inversion pulse for wideband LGE. We demonstrate that the wideband HS4 pulse is superior to the wideband HS pulse in eliminating hyperintensity artifacts resulting from off-resonance induced by an ICD in the myocardium.

Yoshiaki Morita¹, Naoaki Yamada¹, Emi Tateishi², Teruo Noguchi², Masahiro Higashi¹, and Hiroaki Naito^1
1Department of Radiology, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan, ²Division of Cardiology, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan

Myocardial fibrosis is closely related to clinically evident cardiac dysfunction and worse outcomes, such as heart failure and arrhythmia. Therefore, non-invasive methods, which can reliably quantify fibrosis, would be preferable. In this study, we demonstrated that T1-map-derived ECV measurement is a significant independent predictor of major adverse cardiovascular events (MACEs) when compared with the presence of LGE and other risk factors. ECV may thus represent a novel prognostic indicator in patients with DCM.