Cyclic CINE‐balanced steady‐state free precession image intensity variations: Implications for the detection of myocardial edema

Abstract

To evaluate the dependence of CINE-balanced steady-state free precession (bSSFP) image intensities on spatial location, cardiac phase, and disease state. Eight subjects with recent myocardial infarctions and eight age- and sex-matched normal volunteers were studied using CINE-bSSFP imaging to describe cyclic image intensity variations as a function of the cardiac cycle and to optimize and assess the ability of CINE-bSSFP imaging to depict myocardial edema. Signal intensities of the left ventricular (LV) bloodpool and myocardium were measured using region-of-interest analysis across the cardiac cycle. The magnitude and time course of the cyclic variations were evaluated. Mixed-model analysis of variance was used to examine the influence of physical location, cardiac phase, and presence of myocardial infarction. The LV bloodpool and myocardial CINE-bSSFP signal intensities varied significantly with spatial location, cardiac phase, and disease (P < 0.001). Cardiac phase had a significant effect on the signal intensities after adjustments for spatial location. The LV bloodpool signal decreased slowly during systole and rose sharply during LV filling. There were two distinct myocardial intensity peaks, one occurring at peak systole and the other at the end of the LV rapid inflow phase. Myocardial edema was seen as a hyperintense region. Image contrast with adjacent myocardium was the greatest at the end of systole. Detection of myocardial edema using the conventional CINE-bSSFP technique is feasible, but is complicated by normal cyclic changes in myocardial image intensities during the cardiac cycle.