PET Center, Institute of Radiopharmacy, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany.
Magn Reson Med. 2013 Dec;70(6):1535-43. doi: 10.1002/mrm.24601. Epub 2012 Dec 27.
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.
部分容积（PV）效应对动脉自旋标记脑血流研究有显著影响，这是由于空间分辨率有限所致。因此，需要进行准确的 PV 校正（PVC）。PVC 通常基于从分割的高分辨率 T1 加权图像中获得的 PV 图。这些图像的分割容易出错，并且很难将其与单次激发 ASL 图像（如 EPI 生成的图像）进行精确配准。本文提出了一种生成 PV 图的替代方法。
采用 Look-Locker EPI（LL-EPI）采集方法分析 T1 恢复曲线，并随后生成 PV 图。该新方法在五名健康志愿者（平均年龄 30±3.7 岁）中进行了评估。
通过应用线性回归方法进行 PVC，新方法的回归误差降低了 12%。
从 LL-EPI 中提取 PV 图是一种可行的、可能优于基于高分辨率 T1 加权图像分割的标准方法的替代方法。
