采用256层CT全脑灌注研究烟雾病术后桥血管再通及手术前后脑血流动力学的变化

目的 研究256层CT全脑灌注同时评价烟雾病术后桥血管再通及手术前后脑血流动力学变化的可行性.方法 选取25例烟雾病患者在手术前后均行全脑CTP检查.容积CTA图像通过CTP动脉期原始图像获得,并与术后的常规CTA图像进行比较.测量患者手术侧及对侧的大脑中动脉分布区的灌注参数,包括脑血流量(CBF)、脑血容量(CBV)、平均通过时间(MMT)和达峰时间(TTP),计算术侧/对侧相对比值(rCBF、rCBV、rTTP及rMTT值).采用配对t检验或配对秩符号检验比较手术前后CT灌注参数值及相对值的差异.正态分布数据以x±s表示,非正态分布数据以M(P25～P75)表示.结果 25例患者术后桥血管均显示通畅.容积CTA图像与传统CTA图像显示桥血管情况的结果一致.烟雾病患者血管搭桥术后手术侧大脑中动脉分布区的CBF72.86(55.54～112.19)ml·100g-1·min-1]、rCBF1.31(1.05～1.73)]及rCBV(1.45±0.62)明显高于术前的CBF46.72(28.57～57.67)ml·100g-1·min-1]、rCBF0.53(0.33～0.82)]及rCBV(1.01±0.36)(Z值分别为-2.72、-2.98,t=-2.85,P值均＜0.05);术后患侧大脑中动脉分布区的MTT(3.98±2.36)s]、TTP(17.56±4.38)s]及rTTP(1.01±0.09)明显低于术前的MTT(5.43±2.07)s]、TTP(19.40±3.87)s]及rTTP(1.14±0.28)(t值分别为2.41、2.17、2.17,P值均＜0.05).结论 256层CT经单次注射对比剂、单次扫描可同时获得CTA图像及全脑CTP参数图,可对烟雾病术后桥血管再通情况及脑血流动力学变化同时进行评价.

256-slice whole-brain CT perfusion in assessment of graft reperfusion after surgical revascularization and hemodynamic alterations before and after surgery in Moyamoya disease

Objective To explore the feasibility of 256-slice whole-brain CT perfusion (CTP) in evaluate graft reperfusion after surgical revascularization and hemodynamic alterations before and after surgery in Moyamoya disease. Methods Twenty-five cases with Moyamoya disease were scanned on a 256-slice CT.CTP was performed pre- and post- surgical revascularization. The wolumetric CT angiographic ( CTA ) images were generated from volumetric data acquired at the arterial phase of CTP. CBF, CBV, TTP and MTT were measured in functional maps at the operated side within middle cerebral artery perfusion areas and contralateral mirroring areas. Relative CBF( rCBF), relative CBV (rCBV), relative TTP (rTTP), relative MTT (rMTT) were also obtained. Differences in perfusion CT values pre- and post operation were assessed with the paired t test or matched-pairs signed-ranks test. Data with normal distribution was present as : (x-)± s,while those with the non-normal distribution were present as M ( P25-P75 ). Results All the direct graft patencies were displayed on volumetric CTA. No significant differences were found between volumetric CTA and conventional CTA. Postoperative CBF, rCBF and rCBV values of the operated side 72. 86 (55.54-112. 19) ml · 100 g-1 · min-1 , 1. 31 ( 1.05-1.73), 1.45 ±0. 62] were significantly higher than those before operation 46.72(28.57-57.67) ml · 100 g-1 · min-1, 0.53(0.33-0.82), 1.01 ±0.36](Z=- 2.72, - 2. 98, t = - 2. 85, P ＜ 0. 05 ). Postoperative MTT, TTP and rTTP values of the operated side (3.98 ± 2. 36 ) s, ( 17.56 ± 4. 38 ) s, 1.01 ± 0. 09 ] were significantly lower than those before operation (5.43±2.07) s,(19.40±3.87) s,1.14±0.28] (t=2.41,2.17,2.17, respectively, P＜0.05).However, no significant differences were detected for changes of CBV and rMTT after revascularization ( P ＞0. 05). Conclusion 256-slice CT has the potential value for the non-invasive assessment of both the graft patency and cerebral hemodynamics changes in moyamoya disease after surgery with administration of one contrast medium bolus in a single examination.