The overall aim of the National Heart, Lung and Blood Institute (NHLBI)/Suburban Hospital Cardiovascular MRI Research Project is to develop new approaches in assessing patients with cardiovascular disease with MRI technology. 1) Detection and characterization of acute coronary syndrome with MRI. Beyond our initial clinical studies of sensitivity and specificity for diagnosing non-ST elevation acute coronary syndrome (Kwong RY et al. Circulation 2003;107:538-544) we have focused attention on the role of MRI methods sensitive to myocardial edema in evaluating the myocardial area at risk. This work has resulted in technical developments of bright blood T2-weighted methods that improve diagnostic certainty beyond those of commercially imaging methods. 2) Characterizing myocardial infarction and viability with MRI. We have continued to use the phase sensitive reconstruction method of imaging myocardial infarction (Kellman P et al. Magnetic Resonance in Medicine 2002;47:372-383 and Kellman et al. Magn Reson Med 2004;51:408-12) and variants of the computer algorithm used to quantify these and similar images (Hsu L et al. J Magn Reson Imaging. 2006;23(3):309-14;Hsu L et al. J Magn Reson Imaging 2006;23:315-22) in almost all of our clinical and preclinical studies. The non-rigid motion corrected imaging methods have propagated to many other applications including T2 weighted imaging and perfusion imaging. We recently validated that gadolinium based contrast agents correlate with infarct-related fibrosis at resolutions approaching a cellular level (Schelbert E et al. Circ Cardiovasc Imaging. 2010;3(6): 743-752). 3) We have been working on improving first pass myocardial perfusion imaging through careful quantitative analysis. We have made a major advance in the analysis of absolute myocardial perfusion beyond our initial methods which were validated in sub-gram sized pieces of myocardium (Christian TF et al. Radiology 2004;232:677-84). Most recently, we demonstrated that MR first pass perfusion images can be quantified down to a pixel level and thus in regions equivalent to about 32 microliters of myocardium (Hsu L et al. in press). 4) Characterization of myocardial abnormalities. Beyond infarction and ischemia, many disease processes alter the characteristics of myocardium. We have developed methods for separating water and fat in cardiac MR images to improve the diagnosis of arrhythmogenic right ventricular dysplasia (Kellman P et al. Magn Reson Med. 2009;61:215-21). These techniques have a wide range of clinical applications (Kellman P et al. Curr Cardiovasc Imaging Rep. 2010;3(2):83-91) and are the subject of a dedicated workshop sponsored by the International Society of Magnetic Resonance in Medicine next year. 5) Myocardial Extracellular Volume (ECV) Imaging. We have studied the extracellular volume fraction in a large number of patients over the past two years and found subtle but intriguing abnormalities in normal myocardium remote from infarcted myocardium. We have also found the ECV increases with age consistent with an age-related increase in myocardial fibrosis. Since measurements of myocardial T1 is an fundamental determinant of myocardial ECV, we have studied the accuracy and agreement of different T1 mapping methods (Nacif MS et al. J Magn Reson Imaging. Electronically published 2011 Sep 23).
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