ISMRM 21st Annual Meeting & Exhibition 20-26 April 2013 Salt Lake City, Utah, USA

Cutting-Edge Cardiac MRI
Thursday 25 April 2013
Room 150 AG  10:30 - 12:30 Moderators: Orlando P. Simonetti, David E. Sosnovik

10:30 0572.   Introduction
Paul A. Bottomley


10:42 0573.   Feasibility of MRI Attenuation Correction in Cardiac-Gated FDG-PET
Jeffrey MC Lau1, Richard Laforest2, Shivak Sharma1, Jonathan McConathy2, Agus Priatna2,3, Luciano Amado1, Robert J. Gropler2, and Pamela K. Woodard2
1Cardiology, Washington University in St. Louis, Saint Louis, MO, United States, 2Radiology, Washington University in St. Louis, Saint Louis, MO, United States, 3Siemens Medical Solutions, Malvern, PA, United States

The objective of this study is to determine the reproducibility of myocardial specific uptake values (SUVs) obtained in EKG-gated and non-EKG-gated cardiac 18F-FDG PET imaging using an MR attenuation correction (AC) lower case Greek mu-map instead of CT. In non-EKG-gated PET-CT and PET-MR, there is excellent per patient correlation between the SUVs (R2 =0.97). In EKG-gated PET-MR, SUVs vary over the cardiac cycle, with higher SUV at end-systole and lower SUV at end-systole. Our findings show that, despite the marked differences in AC methods, myocardial PET SUVs measured using MR-AC show excellent correlation to myocardial SUVs obtained by standard PET-CT imaging.

10:54 0574.   
Hybrid PET/MRI Imaging of the Heart: Feasibility and Initial Results
Felix Nensa1, Thorsten D. Poeppel2, Karsten Beiderwellen1, Amir Abbas Mahabadi3, Philipp Heusch4, and Thomas Schlosser1
1Radiology, University Hospital Essen, Essen, NRW, Germany, 2Nuclear Medicine, University Hospital Essen, Essen, NRW, Germany, 3Cardiology, University Hospital Essen, Essen, NRW, Germany,4Radiology, University Hospital Duesseldorf, Duesseldorf, NRW, Germany

This study evaluated the potential as well as the challenges of hybrid imaging of the heart with an integrated 3-T PET/MRI system capable of simultaneous data acquisition. In 15 consecutive patients with myocardial infarction (MI; n=10) or suspected myocarditis (n=5) PET/MRI with 18F-FDG showed good concordance between MRI and PET. PET imaging yielded additional insights regarding myocardial viability and inflammatory activity that complemented MRI findings. From our results we conclude, that integrated cardiac PET/MRI with 18F-FDG is feasible, offers a complementary view on myocardial disease and could advance to become the diagnostic tool of choice.

11:06 0575.   in vivo Diffusion Tensor Imaging of the Human Heart with Free-Breathing in Healthy Volunteers
Hongjiang Wei1, Magalie Viallon1,2, Benedicte M.A. Delattre1, Vinay M. Pai3, Han Wen3, Hui Xue4, Christoph Guetter4, Marie-Pierre Jolly4, Pierre Croisille1,5, and Yuemin Zhu1
1CREATIS, CNRS (UMR 5220), INSERM (U1044),INSA Lyon,University of Lyon, Lyon, France, 2Department of Radiology,University Hospitals of Geneva, Geneva, Switzerland, 3Imaging Physics Lab, BBC/NHLBI/NIH, Bethesda, Maryland 20892, United States, 4Siemens Corporation, Corporate Technology, Princeton, New Jersey 08540, United States, 55Jean-Monnet University, Saint-Etienne, France

DTI has the potential to resolve the changes in myocardium microstructure. The biggest problem for in vivo cardiac DTI of the human is the large signal loss caused by physiological motion. Recently, an efficient cardiac DWI method was proposed where motion-induced signal-loss was removed by PCATMIP technique. While performing acquisition during subject’s breath-hold may be difficult to apply in clinical routine. This study we reconstituted DW images with enhanced SNR and calculated the fiber architecture properties such as FA, MD and 3D fiber architecture, and opens an interesting perspective to perform these measurements while subject is freely breathing.

11:18 0576.   
Simultaneous Measurement of Myocardial Perfusion by Dynamic Contrast Enhancement MR and Ammonia PET
HuaLei Shelley Zhang1,2, Christopher Rischpler1, Nicolas Langwieser1, Carmel Hayes3, Anja Batrice1, Tareq Ibrahim1, Karl-Ludwig Laugwitz1, Markus Schwaiger1, and Stephan G. Nekolla1
1Klinikum rechts der Isar der Technischen Universitaet München, Muenchen, Bayern, Germany, 2Brigham and Women's Hospital, Boston, MA, United States, 3Siemens Medical Solutions, Erlangen, Bayern, Germany

The assessment of myocardial perfusion has shown to provide high diagnostic and prognostic information for the management of patients with CAD. Quantification of perfusion remains a challenge for the regional measurement of myocardial flow reserve by a variety of imaging techniques. Newly developed integrated PET/MR devices are uniquely suited to compare perfusion measurements in patients. Here we describe a protocol for parallel acquisitions of myocardial perfusion by PET and MR, and the direct comparison of simultaneous measurements of myocardial perfusion at rest and during pharmacologic stress.

11:30 0577.   in vivo Fluorine-19 MRI at 3 Tesla to Visualize Myocardial Infarction Inflammation in a Porcine Model
Jia Zhong1,2, David Schwartzman3, Claudiu Schirda4, Anthony Balducci5, Brooke Helfer5, Amy Wesa5, and Eric T. Ahrens1,2
1Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States, 2The Pittsburgh NMR Center for Biomedical Research, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States, 3Cardiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States, 4Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States, 5Celsense Inc, Pittsburgh, Pennsylvania, United States

Myocardial infarction (MI) remains a major public health problem worldwide. Leaving untreated, MI can result in permanent left ventricle scarring that may eventually lead to heart failure. Inflammation is a key early response to the ischemic insult, whose location represents a promising spatial cue that can be used to target for therapeutic biological material delivery. In this study, we demonstrated the feasibility of using intravenously infused perfluorocarbon emulsion and 19F MRI detection to visualize myocardial inflammation and macrophage burden in a porcine model of MI. The study was performed with using a 3 Tesla clinical scanner and clinically relevant scan times.

11:42 0578.   
Human Cardiac 31P Magnetic Resonance Spectroscopy at 7 Tesla
Christopher T. Rodgers1, William T. Clarke2, Carl Snyder3, University of Minnesota University of Minnesota Vaughan3, Stefan Neubauer1, and Matthew D. Robson1
1Univ Oxford, Oxford, United Kingdom, 2University of Oxford, Oxford, United Kingdom, 3CMRR, Univ Minnesota, Minneapolis, MN, United States

Cardiac 31P spectroscopy (31P-MRS) provides unique insights into the supply of energy in the heart. However, clinical applications of cardiac 31P-MRS have suffered from a low intrinsic signal-to-noise ratio (SNR). We demonstrate 31P-MRS for the first time in the human heart at 7T. We compare quantitatively the performance at 7T against that at 3T in a study on 9 normal volunteers. The measured SNR for PCr increases by 2.8x, the Cramer-Ráo lower bounds on PCr concentration decrease 4.3x and the PCr/ATP ratio SD decreases by 2x. Clearly, cardiac 31P-MRS at 7T shows great promise.

11:54 0579.   Noninvasive Assessment of Cardiac Work and CK Energy Supply in Healthy and Failing Human Hearts
Refaat E. Gabr1, AbdEl-Monem M. El-Sharkawy1, Michael Schär1,2, Robert G. Weiss1,3, and Paul A. Bottomley1
1Division of MR Research, Department of Radiology, Johns Hopkins University, Baltimore, MD, United States, 2Philips Healthcare, Cleveland, OH, United States, 3Cardiology, Johns Hopkins University, Baltimore, MD, United States

The “energy starvation” hypothesis of heart failure (HF) suggests that energy supply may be compromised. This may limit cardiac mechanical work during peak demand. We developed a comprehensive noninvasive MRI/MRS protocol that combines 31P-MRS measures of creatine-kinase (CK) ATP energy supply with temporal MRI measurements of cardiac mechanical work. Compared to healthy subjects, we find significant reductions of 30-40% in peak cardiac work, average work and mechanical efficiency consistent with a reduction of 40% seen in creatine-kinase energy supply, suggesting that compromised CK energy supply could limit cardiac work in HF.

12:06 0580.   
2D CINE SSFP Imaging at 7.0T Using 8-Channel Bowtie Antenna Transceiver Arrays: A Cardiac MR Feasibility Study
Oliver Kraus1, Matthias Alexander Dieringer1,2, Fabian Hezel1, Lukas Winter1, Andreas Graessl1, Celal Oezerdem1, and Thoralf Niendorf1,2
1Berlin Ultrahigh Field Facility (B.U.F.F.), Max-Delbrueck Center for Molecular Medicine, Berlin, Germany, 2Cardiovascular Magnetic Resonance, Experimental and Clinical Research Center, A joint cooperation between Charité Medical Faculty and Max-Delbrueck Center for Molecular Medicine, Berlin, Germany

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

12:18 0581.   Dynamics of the Fiber Architecture Matrix in the Human Heart In Vivo
Choukri Mekkaoui1, Sonia Nielles-Vallespin2, Marcel Parolin Jackowski3, Timothy G. Reese4, Peter David Gatehouse2, David N. Firmin5, and David E. Sosnovik4
1Harvard Medical School - Massachusetts General Hospital - Athinoula A Martinos center for Biomedical, Boston, MA, United States, 2CMR Unit, Royal Brompton Hospital, London, London, United Kingdom, 3University of São Paulo, São Paulo, São Paulo, Brazil, 4Harvard Medical School - Massachusetts General Hospital - Athinoula A Martinos center for Biomedical, Charlestown, MA, United States, 5CMR Unit, Royal Brompton Hospital, London, London, United States

In vivo Diffusion Tensor MRI (DTI) of the human heart has shown that myofiber architecture is dynamic. However, most architecture-related indices derived from the diffusion tensor have relied solely upon information from the principal eigenvector. Here we introduce the fiber architecture matrix (FAM), which encodes myofiber architecture by the angles of the projections of all three diffusion tensor eigenvectors onto the orthogonal planes of the cardiac coordinate system. Angular variations across the LV wall are seen for all FAM coefficients while the greatest changes between systole and diastole are seen in the elements of the matrix describing sheet architecture.