TRADITIONAL POSTER - ismrm

Poster Sessions
1303. Molecular Imaging of Myocardial Inflammation in Experimental Autoimmune Myocarditis Rats with
Magnetofluorescent Nanoparticles
Hyeyoung Moon 1 , Hyo Eun Park 2 , Quan-Yu Cai 1 , Jongeun Kang 1 , Kiyuk Chang 2 , Kwan Soo Hong 1
1 Magnetic Resonance Imaging Team, Korean Basic Science Institute, Ochang-Myun, Cheongwon-Gun, Korea, Republic of;
2 Department of Internal Medicine, Catholic University, Seoul, Korea, Republic of
In this study, we investigated whether magnetic nanoparticle-contrasted cardiac magnetic resonance imaging would be feasible and effective for the
detecting the inflammation in a rat model of experimental autoimmune myocarditis, and whether MNP-contrasted CMR imaging could give a guidance
where the biopsy samples should be collected.
1304. Rotating Frame, Spin Lattic Relaxation in a Swine Model of Late Ventricular Myocardial Infarction
Walter RT Witschey 1,2 , James J. Pilla 2 , Giovanni Ferrari 2 , Keivn Koolmasingh 2 , Mohammed Haris 1 , Robin
Hinmon 2 , Gerald A. Zsido 1 , Joseph H. Gorman III 2 , Robert C. Gorman 2 , Ravinder Reddy 1
1 Center for Magnetic Resonance and Optical Imaging, Department of Radiology, University of Pennsylvania, Philadelphia, PA,
United States; 2 Department of Surgery, University of Pennsylvania, Philadelphia, PA, United States
T1ρ MRI was performed to differentiate scar tissue, proximal, borderzone tissue and healthy myocardium in a swine model of left ventricular myocardial
infarction. The spatially-dependent relaxation times were validated by histological staining of collagen and myocytes. Significant magnetic relaxation
dispersion with the application of a varying amplitude RF field was observed. These results suggest that T1ρ is superior to conventional methods such as T2
for the visualization of early edema and late scarring and expansion in patients with ischemic cardiomyopathy.
1305. Myocardial Extracellular Volume Imaging - Phantom Validation and Patient Feasibility for
Quantitative Pixel Mapping of the Fractional Distribution Volume of Extracellular Contrast Agents by MRI
Martin Ugander 1 , Abiola J. Oki 1 , Peter Kellman 1 , Andreas Greiser 2 , Anthony H. Aletras 1 , Andrew E. Arai 1
1 National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, United States; 2 Siemens AG Healthcare
Sector, Erlangen, Germany
T1-mapping of the heart before and after intravenous contrast administration can be used to generate quantitative pixel-maps of the extracellular volume
(ECV) fraction of the myocardium in patients. The study presents comprehensive phantom, experimental and patient validation of the T1 mapping sequence
(MOLLI) which is used to calculate ECV. The method provides images for quantitative assessment of the ECV of the myocardium, and in principle any
other tissue, in a pixel map with a quantitative color scale ranging from 0-100%.
1306. Tracking Edema, Hemorrhage and Microvascular Obstruction by MRI After Acute Myocardial
Infarction
Nilesh R. Ghugre 1 , Venkat Ramanan 1 , Mihaela Pop 2 , Yuesong Yang 1 , Jennifer Barry 1 , Beiping Qiang 1 , Kim
Connelly 3 , Alexander J. Dick 1 , Graham A. Wright 1,2
1 Imaging Research, Sunnybrook Health Sciences Centre, Toronto, ON, Canada; 2 Department of Medical Biophysics, University of
Toronto, Toronto, ON, Canada; 3 Division of Cardiology, St. Michael's Hospital, Toronto, ON, Canada
Pathophysiological responses after acute myocardial infarction (AMI) include edema, hemorrhage and microvascular obstruction (MVO) along with cellular
damage. The in vivo evolution of these processes throughout infarct healing has not been well characterized. The purpose of our study was to monitor the
time course of edema (T2), hemorrhage (T2*) and MVO in porcine myocardium following AMI and to observe the relative resolution of these
pathophysiological mechanisms. Our study suggests that quantitative T2 and T2* mapping techniques are potentially more specific than intensity measures
in single images, allowing regional, longitudinal and cross-subject comparisons. Such in vivo characterization will be important in grading severity and
evaluating treatment strategies in AMI, potentially improving clinical outcome.
1307. On the Mechanism of Myocardial Edema Contrast in SSFP Imaging
Xiangzhi Zhou 1 , Veronica Rundell 1 , Ying Liu 1 , Richard Tang 1 , Rachel Klein 1 , Shivraman Giri 2 , Saurabh
Shah 3 , Sven Zuehlsdorff 3 , Orlando Simonetti 2 , Debiao Li 1 , Rohan Dharmakumar 1
1 Northwestern University, Chicago, IL, United States; 2 Ohio State University, Columbus, OH, United States; 3 Siemens Medical
Solutions USA, Inc., Chicago, IL, United States
The mechanism of bSSFP edema contrast in acute myocardial infarction imaging is not well understood. To assess the various mechanisms that enable the
detection of myocardial edema on the basis on bSSFP imaging, controlled experiments were conducted in canine models subjected to ischemia reperfusion
injury. Results show that relaxation and M0 changes have significant contribution to the detection of edematous myocardial zones following acute injury to
the myocardium on the basis bSSFP imaging.
1308. On the Origin of Myocardial Edema Contrast in T2-STIR Images
Xiangzhi Zhou 1 , Veronica Rundell 1 , Ying Liu 1 , Richard Tang 1 , Rachel Klein 1 , Shivraman Giri 2 , Saurabh
Shah 3 , Sotirios A. Tsaftaris 1 , Sven Zuehlsdorff 3 , Orlando Simonetti 2 , Debiao Li 1 , Rohan Dharmakumar 1
1 Northwestern University, Chicago, IL, United States; 2 Ohio State University, Columbus, OH, United States; 3 Siemens Medical
Solutions USA, Inc., Chicago, IL, United States
The biophysical mechanisms contributing to myocardial edema contrast in T2-weighted STIR images was studied using dogs subjected to ischemiareperfusion
injury. It is shown that in addition to T2-weighting, edema detection in acute myocardial infarcts with T2-weighted STIR images have
substantial weighting from proton density changes. This finding suggests that myocardial edema detection sensitivity is enhanced when acquisition strategies
permit sensitivity to proton density, as well as T2 changes.