Browsing by Author "Jensen, Christoph J"

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    Dark-Blood Delayed Enhancement Cardiac Magnetic Resonance of Myocardial Infarction.
    (JACC Cardiovasc Imaging, 2017-12-08) Kim, Han W; Rehwald, Wolfgang G; Jenista, Elizabeth R; Wendell, David C; Filev, Peter; van Assche, Lowie; Jensen, Christoph J; Parker, Michele A; Chen, Enn-Ling; Crowley, Anna Lisa C; Klem, Igor; Judd, Robert M; Kim, Raymond J
    OBJECTIVES: This study introduced and validated a novel flow-independent delayed enhancement technique that shows hyperenhanced myocardium while simultaneously suppressing blood-pool signal. BACKGROUND: The diagnosis and assessment of myocardial infarction (MI) is crucial in determining clinical management and prognosis. Although delayed enhancement cardiac magnetic resonance (DE-CMR) is an in vivo reference standard for imaging MI, an important limitation is poor delineation between hyperenhanced myocardium and bright LV cavity blood-pool, which may cause many infarcts to become invisible. METHODS: A canine model with pathology as the reference standard was used for validation (n = 22). Patients with MI and normal controls were studied to ascertain clinical performance (n = 31). RESULTS: In canines, the flow-independent dark-blood delayed enhancement (FIDDLE) technique was superior to conventional DE-CMR for the detection of MI, with higher sensitivity (96% vs. 85%, respectively; p = 0.002) and accuracy (95% vs. 87%, respectively; p = 0.01) and with similar specificity (92% vs, 92%, respectively; p = 1.0). In infarcts that were identified by both techniques, the entire length of the endocardial border between infarcted myocardium and adjacent blood-pool was visualized in 33% for DE-CMR compared with 100% for FIDDLE. There was better agreement for FIDDLE-measured infarct size than for DE-CMR infarct size (95% limits-of-agreement, 2.1% vs. 5.5%, respectively; p < 0.0001). In patients, findings were similar. FIDDLE demonstrated higher accuracy for diagnosis of MI than DE-CMR (100% [95% confidence interval [CI]: 89% to 100%] vs. 84% [95% CI: 66% to 95%], respectively; p = 0.03). CONCLUSIONS: The study introduced and validated a novel CMR technique that improves the discrimination of the border between infarcted myocardium and adjacent blood-pool. This dark-blood technique provides diagnostic performance that is superior to that of the current in vivo reference standard for the imaging diagnosis of MI.
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    Relationship of T2-Weighted MRI Myocardial Hyperintensity and the Ischemic Area-At-Risk.
    (Circ Res, 2015-07-17) Kim, Han W; Van Assche, Lowie; Jennings, Robert B; Wince, W Benjamin; Jensen, Christoph J; Rehwald, Wolfgang G; Wendell, David C; Bhatti, Lubna; Spatz, Deneen M; Parker, Michele A; Jenista, Elizabeth R; Klem, Igor; Crowley, Anna Lisa C; Chen, Enn-Ling; Judd, Robert M; Kim, Raymond J
    RATIONALE: After acute myocardial infarction (MI), delineating the area-at-risk (AAR) is crucial for measuring how much, if any, ischemic myocardium has been salvaged. T2-weighted MRI is promoted as an excellent method to delineate the AAR. However, the evidence supporting the validity of this method to measure the AAR is indirect, and it has never been validated with direct anatomic measurements. OBJECTIVE: To determine whether T2-weighted MRI delineates the AAR. METHODS AND RESULTS: Twenty-one canines and 24 patients with acute MI were studied. We compared bright-blood and black-blood T2-weighted MRI with images of the AAR and MI by histopathology in canines and with MI by in vivo delayed-enhancement MRI in canines and patients. Abnormal regions on MRI and pathology were compared by (a) quantitative measurement of the transmural-extent of the abnormality and (b) picture matching of contours. We found no relationship between the transmural-extent of T2-hyperintense regions and that of the AAR (bright-blood-T2: r=0.06, P=0.69; black-blood-T2: r=0.01, P=0.97). Instead, there was a strong correlation with that of infarction (bright-blood-T2: r=0.94, P<0.0001; black-blood-T2: r=0.95, P<0.0001). Additionally, contour analysis demonstrated a fingerprint match of T2-hyperintense regions with the intricate contour of infarcted regions by delayed-enhancement MRI. Similarly, in patients there was a close correspondence between contours of T2-hyperintense and infarcted regions, and the transmural-extent of these regions were highly correlated (bright-blood-T2: r=0.82, P<0.0001; black-blood-T2: r=0.83, P<0.0001). CONCLUSION: T2-weighted MRI does not depict the AAR. Accordingly, T2-weighted MRI should not be used to measure myocardial salvage, either to inform patient management decisions or to evaluate novel therapies for acute MI.