[Tissue characteristics in left ventricular hypertrophy using magnetic resonance imaging].

For 15 normotensive patients with asymmetric septal hypertrophy (ASH), 10 hypertensive patients with concentric hypertrophy (CH), and five normal subjects (N), we examined changes in myocardial T1 and T2 values related to the cardiac cycle. The usefulness of those values in differentiating diseases with left ventricular hypertrophy was evaluated. Left ventricular (LV) short-axis spin echo images and inversion recovery images were obtained at endsystolic and diastolic cardiac phases, and T1 and T2 images were calculated. The regional wall thickness (WT) and T1 and T2 values were measured in the anterior septum, anterior wall, lateral wall, posterior wall and posterior septum. Myocardial T1 and T2 values were significantly decreased in systole (T1: 185.6 +/- 37.9 msec, T2: 24.4 +/- 6.3 msec, mean +/- SD) compared to those in diastole (T1: 249.2 +/- 56.7 msec, T2: 31.7 +/- 9.4 msec). In both the ASH and CH groups, significant correlations were observed between diastolic T1 values and WT (ASH: r = 0.80, p less than 0.01, CH: r = 0.45, p less than 0.01), and between diastolic T2 values and WT (ASH: r = 0.58, p less than 0.01, CH: r = 0.60, p less than 0.01). In the regions where diastolic WT were more than 17 mm, T1 values in the ASH group (343.4 +/- 40.5 msec) were significantly higher than those of the CH group (247.3 +/- 21.4 msec), although the mean wall thickness values were similar in both groups. The T1/WT and T2/WT were significantly lower in the CH group than those in the ASH and N groups.(ABSTRACT TRUNCATED AT 250 WORDS)