kt SPIRiT for Ultra-Fast Cardiac Cine Imaging with Prospective or Retrospective Cardiac Gating
Peng Lai¹, Michael Lustig^2,3, Anja CS. Brau¹, Shreyas Vasanawala^4
1Applied Science Laboratory, GE Healthcare, Menlo Park, CA, United States; ²Electrical Engineering, Stanford University, Stanford, CA, United States; ³Electrical Engineering and Computer Science, University of California, Berkeley, CA, United States; ⁴Radiology, Stanford University, Stanford, CA, United States

This work developed a new kt method, kt SPIRiT, for highly accelerated cardiac cine imaging. kt SPIRiT exploits both k-space correlations (parallel imaging) and intrinsic spatiotemporal sparsity (compressed sensing) in dynamic images and supports both prospective and retrospective cardiac gating. The proposed method was compared with kt GRAPPA and kt SPARSE on 6 volunteers. Based on our visual assessment and quantitative analysis, kt SPIRiT can improve image quality and reconstruction accuracy compared to kt GRAPPA and kt SPARSE and provide results similar to full k-space reconstruction at high acceleration factors.

3D Whole Heart CSPAMM Tagging in a Single Breath Hold Using K-T-PCA
Christian Torben Stoeck^1,2, Reza Nezafat³, Peter Boesiger¹, Sebastian Kozerke^1
1Institute for Biomedical Engineering, University and ETH, Zurich, Switzerland; ²Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard , Boston, MA, United States; ³Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center and Harvard, Boston, MA, United States

The feasibility of undersampling 3D whole heart CSPAMM tagging data using k-t PCA was investigated. In computer simulations it is shown that acceleration factors up to 3.7 can be achieved without compromising the accuracy in determining motion parameters such as circumferential strain, circumferential shortening and rotation. This opens up the possibility to acquire 3D CSPAMM data in a single breathhold thereby eliminating the need for repetitive breathholding.

Assessment and Validation of Cardiac MR Oximetry in Obesity
Jie Zheng¹, Donna Lesniak², Robert O'Connor, David Muccigrosso, Linda Peterson, Chris Eagon, Pamela K. Woodard, Robert J. Gropler
¹Radiology, Washington University in St. Louis, Saint Louis, MO, United States; ²Radiology, Washington University in St. Louis, United States

Obese patients underwent gastric bypass surgery and then scanning by positron emission tomography for cardiac evaluation, including perfusion and oxygen consumption. A cardiac MR acquisition method and modeling were developed to quantify global myocardial oxygen extraction fraction and oxygen consumption in these patients and BMI matched volunteers, at rest and during the hyperemia Excellent correlation was observed for oxygen extraction fraction and consumption rate between MRI and PET. Mismatched myocardial blood flow and hyperemic OEF, observed in obesity, indicates metabolism alternation may precede myocardial microcirculation abnormality in obese.

Free-Breathing Perfusion Imaging with SW-CG-HYPR and Motion Correction
Lan Ge¹, Aya Kino¹, Mark Griswold², James Carr¹, Debiao Li^1
1Departments of Radiology and Biomedical Engineering, Northwestern University, Chicago, IL, United States; ²Departments of Radiology and Biomedical Engineering, Case Western Reserve University, OH, United States

Time-resolved data acquisition with Sliding-Window Conjugate-Gradient HighlY constrained back PRojection (1, 2) (SW-CG-HYPR) has been used to acquire myocardial perfusion images with increased spatial coverage, better spatial resolution, and improved SNR (3). However, this method is sensitive to respiratory motion; therefore, breath-hold is required during data acquisition. In this work, we developed a motion correction method for SW-CG-HYPR, allowing free-breathing myocardial perfusion MRI. The average image quality score of the free-breathing images with motion correction (3.09±0.37) is significantly higher than that without motion correction (2.26±0.40), and is comparable to the successful breath-holding images (3.10±0.41). The signal changes in motion corrected free-breathing images were closely correlated to the breath-holding images, with a correlation coefficient of 0.9764 for myocardial signals.

Comparison of Single to Dual Bolus MR Myocardial Perfusion Imaging for Detection of Coronary Artery Disease
Frans PPJ Kremers¹, Jan GJ Groothuis², Aernout M. Beek², Stijn L. Brinckman², Alvin C. Tuinenburg², Michael Jerosch-Herold³, Albert C. van Rossum², Mark B.M. Hofman^1
1Physics and Medical Technology, ICaR-VU, VU University Medical Center, Amsterdam, Netherlands; ²Cardiology, ICaR-VU, VU University Medical Center, Amsterdam, Netherlands; ³Radiology, Brigham & Women's Hospital, Boston, MA, United States

Dual-bolus first pass MR myocardial perfusion imaging has been shown to compensate for signal saturation in arterial input function, and resulted into more realistic perfusion values. We investigated whether this dual bolus approach also improved diagnostic value for the detection of significant coronary artery disease (CAD). In 49 patients with suspected CAD adenosine stress and rest MR perfusion imaging was performed with single and dual bolus imaging. Invasive coronary angiography was used as standard of reference. Dual bolus imaging showed lower perfusion values, but ROC analysis showed no incremental diagnostic value over single bolus technique for detection of significant CAD.

Manganese Uptake in Heart Is Dependent of L-Type Calcium Channel Activity But Not Extracellular Calcium Concentration
Ya Chen^1,2, Wen Li^1,2, Wei Li^1,2, Xin Yu^1,2
1Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States; ²Case Center for Imaging Research, Case Western Reserve University, Cleveland, OH, United States

The present study aimed to quantify manganese (Mn2+) uptake in hearts under altered physiological and biochemical conditions. Using a rapid T1-mapping method, we investigated the dynamic Mn2+ uptake in perfused rat hearts 1) under normal workload; 2) under isoproterenol (ISO) stimulation, and 3) at elevated calcium (Ca2+) concentration. Our results show that Mn2+ uptake was increased in ISO stimulated hearts but not in hearts perfused with increased Ca2+ concentration.

Diffusion Weighted MRI of the Mouse Heart in Vivo Following Ischemia-Reperfusion Injury
Shuning Huang¹, Guangping Dai¹, David E. Sosnovik^1,2
1Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States; ²Center for Molecular Imaging Research, Massachusetts General Hospital, Charlestown, MA, United States

We present in the study, to the best of our knowledge, the first diffusion weighted MR images of the mouse heart to be acquired in vivo. Schemes to overcome motion artifact in the rapidly beating mouse heart are presented, and the ability of the technique to detect changes in cell death in the myocardium after an ischemic insult is demonstrated.

A Comparative Study of Different CMR Methods for Detecting Myocardial Edema Associated with Acute Myocardial Infarction
Xiangzhi Zhou¹, Veronica Rundell¹, Ying Liu¹, Richard Tang¹, Rachel Klein¹, Shivraman Giri², Saurabh Shah³, Sven Zuehlsdorff³, Orlando Simonetti², Debiao Li¹, Rohan Dharmakumar^1
1Northwestern University, Chicago, IL, United States; ²Ohio State University, Columbus, OH, United States; ³Siemens Medical Solutions USA, Inc., Chicago, IL, United States

The sensitivity of T1 and T2 maps, T2-prep SSFP, bSSFP, and T2-STIR, for detecting myocardial edema in AMI was assessed in a canine model subjected to ischemia reperfusion injury. T1 and T2 maps showed lower sensitivity compared to T2-STIR. However, no difference was found among T2-STIR, T2-Prep, and bSSFP methods.

Simultaneous T1 Mapping, Cine Imaging, and IR-Prepared Imaging of the Rat Heart Using Small Animal Look-Locker Inversion Recovery (SALLI)
Daniel R. Messroghli¹, Martin Buehrer², Sebastian Kozerke², Sarah Nordmeyer¹, Thore Dietrich³, Kirstin Atrott³, Thomas Hucko³, Ingo Paetsch³, Felix Berger¹, Eckart Fleck³, Titus Kuehne^1
1Congenital Heart Disease and Paediatric Cardiology, Deutsches Herzzentrum Berlin, Berlin, Germany; ²Institute for Biomedical Engineering, University and ETH Zuerich, Switzerland; ³Internal Medicine and Cardiology, Deutsches Herzzentrum Berlin, Germany

Small Animal Look-Locker Inversion recovery (SALLI) is a novel imaging and reconstruction strategy allowing for simultaneous acquisition of cardiac T1 maps, cine movies, and IR-prepared images. Phantom experiments illustrate the T1 behavior of SALLI T1 maps using different sets of timing parameters. In-vivo images were obtained in a rat heart with acute anterior myocardial infarction and allowed to clearly identify the infarction site on all three modalities in a time-effective manner.

Assessment of Pericardial Enhancement in Pericarditis with a Novel Fat-Water Separated 3D Dixon Delayed Enhancement Pulse Sequence
James F. Glockner¹, Jae K. Oh², Manojkumar Saranathan^3
1Radiology, Mayo Clinic, Rochester, MN, United States; ²Cardiology, Mayo Clinic, Rochester, MN, United States; ³GE Healthcare, Waukeshau, WI, United States

Pericardial enhancement has been correlated with pathologic evidence of inflammation, and therefore can serve as a marker of pericarditis.  Visualization of pericardial enhancement with MRI can be limited using traditional delayed enhancement sequences without fat suppression.  We assessed a 3D Dixon FGRE fat-water separated delayed enhancement sequence in 21 patients with known or suspected pericarditis, and found that pericardial visualization and confidence in presence or absence of pericardial enhancement were significantly improved in comparison to a standard 2D DE pulse sequence.