Quantitative assessment of myocardial motion from displacement measurements derived from velocity encoded MRI

Methods 12 volunteers (30±8 years) and 3 patients (41±11 years) were investigated at a 3T whole body MR scanner (Achieva, Philips) with a 32 channel coil. The patients suffer from DCM, asynchrony and/or LBBB. A velocity encoded navigated segmented gradient echo sequence was applied in the apical, equatorial and basal slice. Acquisition parameters: FOV=340mm, in-plane res. =2.5mm, slice thickness =8mm, TR/TE=6.3ms/4.6ms, a=15°, 3 k-lines per segment, VENC=30cm/s,scan duration =5.51 min., black blood imaging with alternating presaturation pulses[1], SENSE=2 and 32 cardiac phases for 60 bpm. Displacement and strain were calculated from the TPM data. Quantitative parameters derived included: circumferential and radial temporal uniformity of strain (TUS)[2-5], regional variance of strain (RVS) and regional variance of principle strain(RVVPS)[2], standard deviation of onset and peak time (SD(Tonset),SD(Tpeak)) [6], coefficient of variance (CV) and difference between septal and lateral peak circumferential strain (DiffSLpeakCS)[6,7], the absolute values of the OS and PS delay vector between septal-lateral (SL), inferior-anterior (IA) and apical-basal (AB) wall[8,9] and the base apex rotation coefficient (BARC)[10].