Partial volume correction in arterial spin labeling using a Look-Locker sequence
Partial volume (PV) effects are caused by limited spatial resolution and significantly affect cerebral blood flow investigations with arterial spin labeling. Therefore, accurate PV correction (PVC) procedures are required. PVC is commonly based on PV maps obtained from segmented high-resolution T1-weighted images. Segmentation of these images is error-prone, and it can be difficult to coregister these images accurately with the single-shot ASL images such as those created by echo-planar imaging (EPI). In this paper, an alternative method for PV map generation is proposed.
The Look-Locker EPI (LL-EPI) acquisition is used for analyzing the T1-recovery curve and for subsequent PV map generation. The new method was evaluated in five healthy volunteers (mean age 30 ± 3.7 years).
By applying a linear regression method for PVC, a 12% decrease in regression error was reached with the new method.
PV maps extraction from LL-EPI is a viable, possibly superior alternative to the standard approach based on segmentation of high-resolution T1-weighted images. Magn Reson Med 70:1535–1543, 2013. © 2012 Wiley Periodicals, Inc.