Purpose: Contrast-enhancement with cine magnetic resonance imaging (cecineMRI) using balanced turbo field echo (BTFE) was performed for direct correlation of transmural extent of hyperenhancement and that of contractility.
Methods: MRI was performed in 25 patients (41-78 yrs, mean 59) with acute myocardial infarction 1 to 2 month after revascularization with 1.5 T. Cine MRI was performed 5 minutes after administration of Gadodiamide with a dose of 0.2 mmol/kg body weight. Retrospectively ECG-gated breath-hold cine imaging was performed in the short axis of the left ventricle by using segmented BTFE pulse sequence. Delayed contrast-enhanced MRI (dceMRI) with the same registered slices as cine imaging was performed with a multi-shot, turbo field echo, breath-hold sequence and a non-selective, inversion prepulse with around 280 msec of inversion delay time about 10 minutes after contrast-agent administration.
Results: All patients showed hyperenhancement with dceMRI, transmural; 8, subendocardial; 17. The signal intensity of enhanced regions in cecineMRI was significantly higher than normal myocardium in end-diastole (159%) and end-systole (154%) (214±38>136±28, 204±42>133±28 respectively). In 22 patients, the hyperenhanced regions of the dceMRI were exactly same as the enhanced regions of the cecineMRI by visual assessment of the location and shape of the enhanced regions. The rest 3 patients with subendocardial hyperenhancement in ceMRI showed almost transmural enhancement in cecineMRI. The size of the enhanced area between dceMRI and cecineMRI was similar but difficult to compare because of inaccurate imaged cardiac phase of dceMRI. The transmurally enhanced segments in 7 patients showed no evidence of systolic thickening in cecineMRI. However, epicardially nonenhanced regions in 13 patients showed more systolic thickening than the subendocardially hyperenhan! ced regions. Unusually, enhanced regions in cecineMRI in 3 patients showed systolic thickening.
Conclusion:
CecineMRI is a simple and useful method to identify not only transmural extent of nonenhanced and potentially salvageable myocardium but also that of the residual or recovered contractility.
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