Reduced susceptibility effects in perfusion fMRI with single-shot spin-echo EPI acquisitions at 1.5 tesla
- 作者：Wang ; Jiongjiong ; Li ; Lin ; Roc ; Anne C. ; Alsop ; David C. ; Tang ; Kathy ; Butler ; Norman S. ; Schnall ; Mitchell D. ; et. al.
- 关键词：Arterial spin label ; Susceptibility artifacts ; Spin-echo EPI ; Perfusion fMRI
- 刊名：Magnetic Resonance Imaging
- 出版年：2004
- 期刊代码：188_0730725x
- 类别：med
- 出版时间：January, 2004
- 卷：22
- 期：1
- 页码：1-7
- 文件大小：281 K
摘要
Arterial spin labeling (ASL) perfusion contrast is not based on susceptibility effects and can therefore be used to study brain function in regions of high static inhomogeneity. As a proof of concept, single-shot spin-echo echo-planar imaging (EPI) acquisition was carried out with a multislice continuous ASL (CASL) method at 1.5T. A bilateral finger tapping paradigm was used in the presence of an exogenously induced susceptibility artifact over left motor cortex. The spin-echo CASL technique was compared with a regular gradient-echo EPI sequence with the same slice thickness, as well as other imaging methods using thin slices and spin-echo acquisitions. The results demonstrate improved functional sensitivity and efficiency of the spin-echo CASL approach as compared with gradient-echo EPI techniques, and a trend of improved sensitivity as compared with spin-echo EPI approach in the brain regions affected by the susceptibility artifact. ASL images, either with or without subtraction of the control, provide a robust alternative to blood oxygenation level dependant (BOLD) methods for activation imaging in regions of high static field inhomogeneity.