不同后标记延迟三维动脉自旋标记技术对大脑中动脉狭窄的评估

Clinical application of different post label delay with 3D arterial spin labeling techniques in patients with middle cerebral artery stenosis

目的:探讨不同后标记延迟(PLD)三维动脉自旋标记(3D-ASL)成像技术在大脑中动脉狭窄(MCA)中临床应用的可行性,并分析脑血流量(CBF)的异常灌注。方法:回顾性分析30例经临床诊断为MCA的资料,根据狭窄侧供血区DWI是否有高信号分为DWI阳性组及DWI阴性组。分别测量不同PLD(1.5s,2.5s)狭窄侧的CBF值对侧镜像区的CBF值,并计算两者比值。比较分析各组狭窄侧灌注的差异性,以及狭窄侧不同PLD(1.5s,2.5s)测得CBF值的差异性。结果:30例狭窄侧均表现为低或等灌注。其中DWI阳性组18例,PLD1.5s时,灌注减低15例,灌注正常3例;PLD2.5s时,灌注减低14例,灌注正常4例。DWI阴性组12例,PLD1.5s时,灌注减低10例,灌注正常2例;PLD2.5s时,灌注减低4例,灌注正常8例。在DWI阳性组,不同的PLD(1.5s,2.5s)在狭窄侧的低灌注比较差异无统计学意义(χ^2=1.58,P>0.05);在DWI阴性组,不同的PLD(1.5s,2.5s)在狭窄侧的低灌注比较差异有统计学意义(χ^2=15.32,P<0.05)。在DWI阴性组,用PLD2.5s测得狭窄侧相对CBF值明显高于PLD1.5s时的测值(t=6.52,P<0.05)。结论:不同PLD(1.5s,2.5s)3D-ASL成像技术在MCA中的临床应用是可行性的,能充分评估狭窄侧脑血流灌注的异常行为。

Objective:To investigate clinical application of different post label delay(PLD)with 3D arterial spin labeling(3D-ASL)imaging and analysis of abnormal cerebral blood flow(CBF)perfusion in patients with the middle cerebral artery(MCA)stenosis.Methods:The data of 30 patients with clinically diagnosed MCA stenosis were retrospectively analyzed.According to whether there was hyperintensity in DWI of MCA stenosis side blood supply area,they were divided into two groups:DWI positive group and DWI negative group.The CBF values were measured in different PLD(1.5 s,2.5 s)of the MCA narrow side and the mirror side,respectively,then the CBF value ratios between them were calculated.The perfusion of different PLD in the MCA stenosis side perfusion of each group were compared and analyzed.Results:All 30 patients showed low or equal perfusion in the narrow side of MCA.Among the 18 cases of DWI positive group,there were 15 cases with decreased perfusion and 3 cases with normal perfusion in PLD 1.5 s,while,14 cases with decreased perfusion and 4 cases with normal perfusion in PLD 2.5 s.Among 12 cases of the DWI negative group,there were 10 cases with decreased perfusion and 2 cases with normal perfusion in PLD 1.5 s,while,4 cases with decreased perfusion and 8 cases with normal perfusion in PLD 2.5 s.In DWI positive group,low perfusion in the MCA narrow side between different PLD had no significant difference(χ^2=1.58,P>0.05),however,there was significant difference in the DWI negative group(χ^2=15.32,P<0.05).In the DWI negative group,the rCBF value(0.96±0.15)with PLD 2.5 s measured MCA narrow side was significantly higher than it with PLD 1.5 s(0.78±0.19),and there were significant differences between them(t=6.52,P<0.05).Conclusions:Different PLD(1.5 s,2.5 s)with 3D-ASL imaging for the patients with the MCA stenosis in clinical application is feasible,and could fully evaluate the abnormal cerebral blood flow perfusion with MCA stenosis side.