OBJECTIVETo establish cardiac magnetic resonance imaging(MRI) derived left ventricular (LV) global and region function parameters in normal adults.

METHODSTwenty normal adults were examined with fast imaging employing steady-state(Fiesta) acquisition sequence of cardiac MRI, LV global function and LV region function were measured at basal, middle, apical level and at 16 LV segments. The regional function parameters among different levels and different segments of the same level were analyzed.

RESULTS(1)LV global function: end-diastolic volume (109.17 ± 19.52) ml; end-systolic volume (37.76 ± 14.16) ml;ejection fraction (65.93 ± 7.79) %; wall thickening (83.24 ± 40.82) %; longitudinal shortening (15.51 ± 3.78) %; fractional shortening (31.78 ± 9.55) %;end-diastolic mass (95.20 ± 19.95) g. (2)LV regional function: In each LV level, there was no significant difference in end-systolic wall thickness (P > 0.05). End-diastolic wall thickness and wall thickening were similar between the middle and apical levels, but there were significant differences between middle and apical levels with the basal level(both P < 0.05). End-systolic wall thickness of the middle and the apical level was similar, but there were significant differences between middle and apical levels with the basal level (both P < 0.05). At the segments of the same level, end-diastolic wall thickness and the relevant regional function parameters between the segments of anteroseptal and inferoseptal at base and middle level were similar (P > 0.05); the end-diastolic wall thickness was the largest and the WT was the minimal at the septal segments of three levels, and the difference were significant between the septal and other segments in the same level (P < 0.05).

CONCLUSIONSFractional shortening and longitudinal shortening provide new indicators for assessing LV global function by cardiac MRI. There is obvious heterogeneity on LV regional function in normal adults, systolic function is the strongest in apical level and the weakest in spetal segments of LV.