MR imaging of regional cardiac function: low-pass filtering of wall thickness curves

Wall thickness curves (WTCs) derived from MR images are subject to considerable measurement error. This study determines the effects of low-pass Fourier filtering of WTCs on functional parameters derived from the curve: peak rate of wall thinning (PRWT) and time to PRWT (TPRWT). The inter-subject standard deviation (SD) of PRWT changed from 0.35 to 0.18, and the SD of TPRWT from 34.3 to 29.5. Differences between neighboring segments decreased from 0.31 to 0.15% mean thickness/ms for PRWT (P = 0.012), and from 35.0 to 19.0 ms for TPRWT (P = 0.005). It is concluded that filtering of MR imaging-derived WTCs contributes to a better representation of myocardial wall motion.