Myocardial Tissue Characteristics & Spectroscopy: Human Studies
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Thursday May 12th
Room 511A-C  16:00 - 18:00 Moderators: Sebastian Kozerke and Robert G. Weiss

16:00 611.   Cardiac Magnetic Resonance Quantitative T2 Mapping For Monitoring of Acute Cardiac Transplant Rejection 
Asad Ali Usman1, Kirsi Taimen1, Marie Wasielewski1, Saurabh Shah1,2, Jermey D Collins1, Jennifer M. McDonald1, and James C Carr1
1Radiology - Cardiovascular Imaging, Northwestern University, Chicago, IL, United States, 2Cardiovascular MR Research and Development, Siemens Healthcare, Chicago, IL, United States

This study is aimed at determining whether myocardial edema T2 relaxation time, using a quantitative T2 mapping technique, can predict acute heart transplant rejection and be used for monitoring post treatment edema resolution. We conclude that T2 mapping is a useful tool in acute cardiac transplant rejection monitoring.

16:12 612.   Comparison of the Transverse Relaxation Time of the Left Ventricle during the Mid-diastolic Rest and the End-systolic Rest Periods 
Brice Fernandez1,2, Maelene Lohezic1,2, Lucien Hammen2,3, Jean-Marie Escanyé4,5, Damien Mandry2,4, Jacques Felblinger2,6, and Pierre-André Vuissoz2,3
1Global Applied Science Laboratory, GE Healthcare, Nancy, France, 2IADI Lab, Nancy-Université, Nancy, France, 3U947, INSERM, Nancy, France, 4CHU de Nancy, Nancy, France, 5Biophysics Lab, Nancy-Université, Nancy, France, 6CIT801, INSERM, Nancy, France

Measurement of the transverse relaxation time T2 of the myocardium, which is a useful quantity to detect different cardiac diseases such as heart transplant rejection, is usually performed at mid-diastole. Imaging the LV at end-systole could be helpful as the LV wall is thicker and as the end-systolic rest, when the heart is still, lasts longer than the mid-diastolic one when heart rate is above 85 bpm. In this preliminary study, T2 differences during these two specific periods are investigated. No significant T2 differences were found, indicating that end-systolic rest period could be used for myocardium T2 quantification.

16:24 613.   Quantitative myocardial T2 measurement for systemic sarcoidosis with cardiac involvement: initial results 
Yuesong Yang1, Kim A Connelly2, Meyer Balter3, John J Graham2, Rhonda Walcarius1, Bradley Strauss1, Alexander J Dick4, and Graham A Wright1
1Imaging Research & Cardiology, Sunnybrook Health Sciences Centre, Toronto, ON, Canada, 2Cardiology, St.Michael's Hospital, Toronto, ON, Canada, 3Medicine, Mount Sinai Hospital, Toronto, ON, Canada, 4Ottawa Heart Institute, Ottawa, ON, Canada

Sarcoidosis is a systemic disease with a predilection for pulmonary involvement. Cardiac involvement is a major risk factor for sudden death in these patients due to damage in the cardiac conductance system and associated ventricular arrhythmias. LGE-MRI provides improved sensitivity in the detection of cardiac involvement in systemic sarcoidosis. However, the LGE foci are not specific for cardiac sarcoidosis. We hypothesize that quantitative T2 measurements with MRI may yield new insights for the assessment of cardiac lesions in systemic sarcoidosis. In this study, a decreased T2 measurement from cardiac sarcoid lesions was observed, which may reflect the true pathological features of certain sarcoid lesions with Schaumann bodies of calcified proteins.

16:36 614.   Design of a robust method for suppression of ghosting artifacts due to long T1 species in cardiac imaging 
Elizabeth R Jenista1, Wolfgang G Rehwald2, Nayla Chaptini1, Michele A Parker1, and Raymond J Kim1
1Duke University Medical Center, Durham, NC, United States, 2Cardiovascular MR&D, Siemens Healthcare, Chicago, IL, United States

Delayed enhancement for the detection of myocardial infarction is considered the gold standard, but if there are any long T1 species present, they will appear as bright ghosts in the image, complicating diagnosis. We have developed a post-suppression method that significantly reduces these ghosts.

16:48 615.   Human cardiac T1 measured at 7 Tesla 
Christopher Thomas Rodgers1,2, Stefan Piechnik1, Lance DelaBarre2, Pierre-Francois Van de Moortele2, Carl Snyder2, Stefan Neubauer1, Matthew D. Robson1, and J Thomas Vaughan2
1University of Oxford, Oxford, United Kingdom, 2University of Minnesota, Minneapolis, MN, United States

Cardiac MRI at 7T is an emerging field. So far, volume and function have been measured. Our aim here is to extend the repertoire of 7T cardiac MRI to inversion recovery experiments. We produce an inversion pulse in the heart and use it to measure myocardial T1 at 7T with a modified version of the ShMOLLI Look-Locker inversion recovery experiment. Using a 10ms HS8 adiabatic inversion pulse with peak power 12.8kW, and FLASH imaging we find T1 values of 1405ms (±50) at 7T compared to 980ms at 1.5T, and 1198ms at 3T. We discuss the remaining limitations at 7T.

17:00 616.   Early Cardiovascular MR Imaging Predicts Late Scar Formation in Pulmonary Vein Isolation 
Dana C Peters1, Warren J Manning1,2, Mark E Josephson1, and Jeff Hsing1
1Cardiology, Beth Israel Deaconess Medical Center, Boston, MA, United States, 2Radiology, Beth Israel Deaconess Medical Center

Early findings of edema and injury after pulmonary vein isolation (PVI) might be predictive of later outcome. Eleven atrial fibrillation patients were imaged prior to PVI, 1 day after PVI (early), and >30 days after PVI (late), with a LGE and T2W sequences. Scar and edema were characterized. LGE enhancement is less intense at the early time-point vs later LGE enhancement, while early edema and wall thickening are common. More intense edema early after PVI predicts later scar formation, by LGE.

17:12 617.   Imaging of Hemorrhagic Myocardial Infarction using Susceptibility Weighted Imaging (SWI) 
James William Goldfarb1
1Saint Francis Hospital, Roslyn, New York, United States

The purpose of this study was to investigate the use of susceptibility weighted imaging (SWI) for the determination of hemorrhagic myocardial infarction. Eight patients with acute myocardial infarction participated in this study. Myocardial hemorrhage was clearly seen as possessing negative phase in filtered phase images and as hypo-intense lesions in areas of “no reflow” in susceptibility weighted images. SWI is an effective means of generating high quality images of left ventricular myocardium for tissue characterization.

17:24 618.   Quantitative Assessment of Aldosterone-induced Myocardial Fibrosis by Cardiac Magnetic Resonance 
Mao-Yuan Su1, Vin-cent Wu2,3, Yen-Hung Line2,3, Hsi-Yu Yu4, and Wen-Yieh Isaac Tseng1,5
1Medical Imaging, National Taiwan University Hosptial, Taipei, Taiwan, 2Internal Medicine, National Taiwan University Hosptial, Taipei, Taiwan, 3TAIPAI study group,4Sugery, National Taiwan University Hosptial, Taipei, Taiwan, 5Center for Optoelectronic Biomedicine, National Taiwan University College of Medicine, Taipei, Taiwan

We used quantitative late gadolinium enhancement (LGE) to detect microscopic myocardial fibrosis and study its relationships with the chamber stiffness of the left ventricle (LV). As compared to the normal subjects, patients with primary hyperaldosteronism (PA) had significantly increased enhancement value (EV) (0.45¡Ó0.07 vs. 0.35¡Ó0.09; p=0.016). The EV was significantly correlated with the plasma aldosterone level (r=0.48; p=0.031) and tdec (index of chamber stiffness derived from cine MRI; r= -0.55; p=0.042). In conclusion, quantitative LGE MRI can indicate the degree of microscopic myocardial fibrosis in PA. The measured index of myocardial fibrosis has functional impact on the LV diastolic function.

17:36 619.   Two-dimensional mapping of triglyceride and creatine content of the human heart 
Kilian Weiss1, Nicola Martini2, Peter Boesiger1, and Sebastian Kozerke1
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland, 2Fondazione G. Monasterio CNR-Regione Toscana, Massa, Italy

For non-invasive assessment of myocardial triglyceride and creatine content single voxel proton magnetic resonance has been shown to be valuable tool. However, to study regional differences multi-dimensional information is required. In the current work two dimension Echo-Planar Spectroscopic Imaging is used to assess spatial distributions of myocardial creatine and triglyceride content in a series of healthy volunteers. An important focus is on the estimation of the creatine resonance in correlation with observed field map values and the reproducibility of this approach.

17:48 620.   Three-dimensional local-look spectroscopic imaging of the heart 
Kilian Weiss1, Nicola Martini2, Peter Boesiger1, and Sebastian Kozerke1
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland, 2Fondazione G. Monasterio CNR-Regione Toscana, Massa, Italy

With recent advances in pulse sequence design, the assessment of myocardial triglyceride content by means of 2D spectroscopic imaging techniques has become possible. In the present work, the feasibility of whole-heart 3D spectroscopic imaging is investigated. By replacing signal averaging by a third phase-encoding direction volumetric spectroscopic data are acquired in the beating heart. It is demonstrated that navigated, local-look spectroscopic imaging is feasible and permits mapping of spatial distributions of triglyceride content during free-breathing.