Quantification of cardiac function by conventional and cine magnetic resonance imaging

Abstract

Magnetic resonance imaging (MRI) has been effective for depicting cardiac anatomy and is already established as a technique for the evaluation of some structural abnormalities of the heart and pericardium. With recent advances, MRI can now be used to quantitate cardiac function. Multiphasic ECG-gated spin-echo imaging has been used to quantitate right and left ventricular volumes and ejection fraction, left ventricular mass, and regional myocardial wall thickening. The new technique of cine MRI acquires frames during the cardiac cycle with a time resolution corresponding to 20 msec up to approximately 40 frames for an average cardiac cycle. This technique uses narrow flip angle (30 degrees) and gradient refocused echoes. Cine MRI has been used to measure ventricular volumes and ejection fraction and regional myocardial wall thickening. It is also sensitive to the detection of valvular regurgitation and can provide quantitation of regurgitant volume. This article reviews the current status of MRI for quantitating cardiac function.

Progression of Myocardial Fibrosis Assessed With Cardiac Magnetic Resonance in Hypertrophic Cardiomyopathy

“…The endocardial and epicardial contours of LV myocardium were manually traced in the end-diastolic and the endsystolic phases. End-diastolic volume index, end-systolic volume index, mass, and mass index were measured as previously described (14,15). Maximal LV end-diastolic wall thickness was measured as previously described (16).…”

Abnormal T2-STIR Magnetic Resonance in Hypertrophic Cardiomyopathy: A Marker of Advanced Disease and Electrical Myocardial Instability

“…A commercially available research software package (Mass Analysis, Leyden, The Netherlands) was used to quantify the functional parameters using conventional methods [22]. LV mass index was considered severely increased when it was >3 SD over the upper limit of normality [23].…”

MR imaging of the heart: functional imaging

“…Cine-MRI and breath-hold cine-MRI Electrocardiogram-triggered gradient-echo sequences, during limited flip angles and short TRs, appear as the most efficient modality for dynamic cardiac imaging [1] and are commonly referred to as cine-MRI. These sequences produce images of the same plane at multiple points of the cardiac cycle that can be viewed in a cinematic display so wall motion of the ventricles can be visualized (Fig.…”