Hofmeijer J, Schepers J, van der Worp H B, Kappelle L J, Nicolay K
Department of Neurology, University Medical Center, Utrecht, The Netherlands.
NMR Biomed. 2005 Oct;18(6):390-4. doi: 10.1002/nbm.971.
We compared cerebral blood flow (CBF) parameters obtained by dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) with those obtained by flow-sensitive alternating inversion recovery (FAIR) in brain regions with different perfusion levels in rats with permanent middle cerebral artery (MCA) occlusion. MCA occlusion was performed in 19 rats. T2-weighted MRI, FAIR and DSC-MRI were performed within 48 h after occlusion. CBF parameters were analyzed in regions of interest with either prolonged or less prolonged mean transit time (MTT). Ratios of ipsi- vs contralateral CBF values were calculated and tested for correlation and differences between FAIR and DSC-MRI. FAIR-aCBF ratios correlated significantly with DSC-rCBF ratios. The mean FAIR-aCBF ratio was significantly lower than mean DSC-rCBF ratio in the area with prolonged MTT. In the area with less prolonged MTT, the mean FAIR-aCBF ratio and mean DSC-rCBF values did not differ significantly. We conclude that FAIR correlates with DSC-MRI if perfusion is preserved. FAIR provides lower CBF values than DSC-MRI if perfusion is reduced and MTT is prolonged. This probable underestimation of perfusion may be caused by transit delays. Care should be taken when quantifying CBF with FAIR and when comparing the results of FAIR- and DSC-MRI in areas with hypoperfusion.
我们将动态磁敏感对比磁共振成像（DSC-MRI）获得的脑血流（CBF）参数与血流敏感交替反转恢复序列（FAIR）在永久性大脑中动脉（MCA）闭塞大鼠不同灌注水平脑区获得的参数进行了比较。对19只大鼠进行了MCA闭塞手术。在闭塞后48小时内进行T2加权MRI、FAIR和DSC-MRI检查。在平均通过时间（MTT）延长或未延长的感兴趣区域分析CBF参数。计算同侧与对侧CBF值的比率，并测试FAIR和DSC-MRI之间的相关性和差异。FAIR-aCBF比率与DSC-rCBF比率显著相关。在MTT延长的区域，平均FAIR-aCBF比率显著低于平均DSC-rCBF比率。在MTT未延长的区域，平均FAIR-aCBF比率和平均DSC-rCBF值无显著差异。我们得出结论，如果灌注得以保留，FAIR与DSC-MRI相关。如果灌注减少且MTT延长，FAIR提供的CBF值低于DSC-MRI。这种可能的灌注低估可能是由通过延迟引起的。在用FAIR定量CBF以及在低灌注区域比较FAIR和DSC-MRI结果时应谨慎。
