El-Sayed H. Ibrahim¹, Scott Swanson¹, Jadranka Stojanovska¹, Claire Duvernoy¹, and Rodica Pop-Busui^1
1University of Michigan, Ann Arbor, MI, United States

MRI tagging is a valuable method for evaluating regional heart function. This study compares the harmonic-phase (HARP) and sine-wave modeling (SinMod) tagging analysis techniques for evaluating myocardial strain and torsion in healthy controls and type-1-diabetes patients. All SinMod measurements were significantly larger than those by HARP. Nevertheless, there existed consistency in the measurements by each technique, as seen by the good correlation between the HARP and SinMod measurements in both normals and patients, except for apical strain (patients and controls) and mid-ventricular strain in patients. The inter-observer agreement was better in SinMod than in HARP for both torsion and strain. 

Daniel A Auger¹, Kenneth C Bilchick², and Frederick H Epstein^1,3
1Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, United States, ²Department of Medicine, Cardiovascular Medicine, University of Virginia, Charlottesville, VA, United States,³Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, United States

A widely held goal in cardiac resynchronization therapy (CRT) is to implant the left-ventricular (LV) pacing lead in a late-activating region. Time to peak shortening (TPS) has been used to image mechanical activation; however electrical activation time is directly related to the time of onset of contraction rather than TPS. Using cine DENSE in heart failure patients, we show that the time of onset of shortening (TOS) shows a strong correlation with electrical activation time, whereas a lower correlation was found using TPS. Cine DENSE of TOS is a promising method for the detection of late-activating segments in CRT patients

Jiming Zhang¹, Benjamin Y Cheong¹, Jie Chen¹, Amol Pednekar², Claudio Arena¹, Melissa L Andrews¹, and Raja Muthupillai^1
1Diagnostic and Interventional Radiology, CHI St Luke's Health, Houston, TX, United States, ²Phillips Healthcare, Cleveland, OH, United States

LV chamber volumes measured using MR cine SSFP imaging and trans-mitral flow velocities measured with echo are considered de facto standards for evaluating LV systolic and diastolic function respectively. Our results show that the relative change in LV volume as well as peak LV volume-rate between the early and late filling periods of the cardiac cycle as measured from high-frame rate cine SSFP imaging, correlate well with conventional echo-based diastolic function index (E/A ratio).  The results from the study suggest that a free-breathing, high frame rate MR cine SSFP imaging approach can evaluate both systolic and diastolic function from a single LV volume data-set. 

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

An alternate-cycle acquisition strategy is proposed for 3D whole-heart first-pass perfusion, capturing two separate datasets from the same first-pass, each pushing separate boundaries of currently achievable parameters whilst maintaining clinically feasible acquisition times. It is postulated this approach may also confer an advantage with regard to artefact detection.

Yang Yang¹, Li Zhao², Xiao Chen³, Kelvin Chow⁴, Peter W. Shaw⁴, Jorge A. Gonzalez⁴, Frederick H. Epstein^1,5, Craig H. Meyer^1,5, Christopher M. Kramer^4,5, and Michael Salerno^1,4,5
1Biomedical Engineering, University of Virginia, Charlottesville, VA, United States, ²Radiology, Beth Israel Deaconess Medical Center & Harvard Medical, Boston, MA, United States, ³Medical Imaging Technologies, Siemens Healthcare, Princeton, NJ, United States, ⁴Medicine, University of Virginia, Charlottesville, VA, United States, ⁵Radiology, University of Virginia, Charlottesville, VA, United States

3D CMR perfusion imaging enables whole ventricular coverage at the same cardiac cycle permitting quantification of ischemic burden of patients being evaluated for coronary artery disease.  Current 3D techniques have limited spatial-temporal resolution. We developed an efficient outer-volume suppressed 3D Stack-of-Spiral perfusion sequence with motion-guided compressed sensing reconstruction which can acquire 20 partitions with 2 mm in-plane and 4 mm through-plane resolution with a temporal foot print of 180 ms.  A pilot study of 10 subjects using this technique demonstrates clinically acceptable image quality.

Sandra Hamada¹, Alexander Gotschy^2,3, Lukas Wissmann³, Sebastian Kozerke³, Cosima Jahnke⁴, Ingo Paetsch⁴, Rolf Gebker⁵, Nikolaus Marx⁶, Hatem Alkadhi¹, and Manka Robert^1,7
1Institue of Diagnostic and Interventional Radiology, University Hospital Zurich, Zurich, Switzerland, ²Department and Policlinic of Internal Medicine, University Hospital Zurich, Zurich, Switzerland, ³Institue for Biomecical Engineering, University and ETH Zurich, Zurich, Switzerland, ⁴University Heart Center Leipzig, Leipzig, Germany, ⁵German Heart Institute Berlin, Berlin, Germany, ⁶Department of Cardiology, Pneumology, Angiology and Intensive Care Medicine, University Hospital RWTH Aachen, Aachen, Germany, ⁷Department of Cardiology, University Heart Center, Universitiy Hospital Zurich, Zurich, Switzerland

Coronary heart disease accounts for a large amount of morbidity and mortality in women. To contribute to evidence for non-invasive testing in women, this study compares diagnostic performance of whole heart dynamic 3D myocardial first-pass perfusion stress imaging in female and male with findings in coronary angiography. 61 female and 139 male with suspected and known coronary artery disease were enrolled and a whole heart dynamic 3D-CMR first-pass perfusion imaging was performed at rest and at stress. Whole heart dynamic 3D-CMR perfusion imaging shows high sensitivity, specificity and diagnostic accuracy in women and men and therefore seems to be a suitable testing tool for myocardial ischemia in women and men.  

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

Over the past two decades myocardial BOLD MRI has seen major technical advancements and a number of clinical validation studies. However, the reliability of BOLD MRI still remains a key weakness for its widespread adoption for routine clinical use due to the unpredictable motions during stress tests. We investigated whether the unique pharmocokinetics of regadenoson, a new coronary vasodilator that is rapidly becoming the agent of choice for cardiac stress testing, can be used to markedly improve the reliability of myocardial BOLD MRI. Studies were performed in a canine model and validated in a clinical PET/MR system.

Akimasa Yamada¹, Masaki Ishida¹, Takashi Ichihara², Takahiro Natsume², Yoshitaka Goto¹, Mio Uno¹, Motonori Nagata¹, Yasutaka Ichikawa¹, Kakuya Kitagawa¹, and Hajime Sakuma^1
1Radiology, Mie University Hospital, Tsu-Mie, Japan, ²Faculty of Radiological Technology, Fujita Health University School of Health Science, Toyoake-Aichi, Japan

In this study, we proposed a new method that synergistically analyzes quantitative perfusion MRI and T1-mapping for quantifying k2, as well as K1, myocardial blood flow, lambda and extracellular volume fraction. Nineteen patients with previous myocardial infarction (MI) were studied. Myocardial segments were categorized into 3 groups by presence or absence as well as severity of MI in each segment. Quantitative measurement was successful in all segments with significant difference among the 3 groups of myocardial segments for all tissue kinetic parameters including k2. Synergistic assessment of quantitative perfusion MRI and T1-mapping is promising for more detailed myocardial tissue characterization. 

Georg Spinner¹, Constantin von Deuster^1,2, Christian Torben Stoeck¹, and Sebastian Kozerke^1
1Institute for Biomedical Engineering, ETH Zurich, Zurich, Switzerland, ²Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom

In vivo cardiac Intravoxel Incoherent Motion Imaging (IVIM) is particularly challenging due to low signal-to-noise ratio, cardiac and respiratory motion. To address the limitation, a spin-echo (SE) based sequence employing motion-compensated diffusion gradients during cardiac contraction was used in combination with Bayesian Shrinkage Prior (BSP) inference. In this work, parameter maps of four volunteers (two slices) are compared to standard segmented least squares (LSQ) regression. Bayesian inferred IVIM parameter maps showed reduced intra-subject variation relative to LSQ. It is concluded that the proposed method is a promising alternative to map myocardial perfusion without the need for contrast agent administration.

Hung Phi Do¹, Venkat Ramanan², Graham A Wright^2,3, Nilesh R Ghugre^2,3, and Krishna S Nayak^4
1Department of Physics and Astronomy, University of Southern California, Los Angeles, CA, United States, ²Physical Sciences Platform, Sunnybrook Research Institute, Toronto, ON, Canada, ³Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada, ⁴Ming Hsieh Department of Electrical Engineering, University of Southern California, Los Angeles, CA, United States

Myocardial vasodilatory response is an important indicator of microvascular function and viability. Arterial spin labeled (ASL) CMR is a non-contrast method that can quantify myocardial blood flow making it attractive to study vasodilatory response. In this work, we demonstrate the feasibility of ASL in the assessment of regional vasodilatory response in a porcine model of acute myocardial infarction (AMI) using a pharmacological stress agent. Quantitative monitoring of microvascular function in the infarcted, salvageable and remote myocardial territories may potentially help identify patients who are prone to adverse long-term remodeling post-AMI.