Evaluation of myocardium in ischemic heart disease by ultrafast computed tomography

In this study we evaluated quantitatively the contrast enhancement of the myocardium of 27 patients with infarction and ischemia by ultrafast CT (Imatron C-100) with a scan time of 100 msec. We defined three parameters from the CT numbers of the myocardium and the ventricle in both the early and the late phase (about 4 min) after the injection of non-ionic contrast material; the difference of the CT numbers of myocardium between the early and the late phase (delta CT#), and the ratios of the CT numbers of the myocardium and the ventricular lumen (M/L) in both the early phase and the late phase. The delta CT# for myocardial infarction and severe ischemia were -20 +/- 10HU and -8 +/- 10HU, respectively. These values were significantly lower than the mild ischemic myocardium and normal myocardium (p less than 0.001). The average M/L values for myocardial infarction and ischemia in the early phase were 19 +/- 8% and 16 +/- 6%, respectively. These values were significantly lower than those in normal myocardium (p less than 0.001). The average M/L values for infarction and severe ischemia in the late phase were 90 +/- 18% and 63 +/- 20%, respectively. These M/L were significantly dissociated (p less than 0.001). Our results indicate that with contrast UFCT it is feasible to detect quantitatively the myocardial characteristics of ischemia and infarction.