磁共振血管造影与CT血管造影诊断脑血管痉挛的对照分析

Vasospasm after subarachnoid hemorrhage:diagnosis with MR angiography and CT angiography

目的评价磁共振血管造影(MRA)与螺旋CT血管造影(CTA)对脑血管痉挛(CV)的诊断价值。方法急性蛛网膜下腔出血(SAH)患者10例,出血停止后5～10 d行MRA检查,CTA在MRA后24 h内进行。每例CV检查5个脑动脉位置:颈内动脉鞍上段(ICA),大脑中动脉(MCA)M1、M2段及大脑前动脉(ACA)A1、A2段。CV根据管腔直径分为:无痉挛、轻度痉挛(管腔缩小<30%)、中度痉挛(管腔缩小30%～50%)、重度痉挛(管腔缩小>50%)。结果MRA与CTA对全部5个位置CV程度检出的一致性达到82%,相关因子为0.76,对近端血管相关性好过远端血管。MRA对无痉挛(89%)及重度痉挛(100%)的检出与CTA的相关程度高(r=0.85～0.91),对轻度痉挛(56%)及中度痉挛(67%)相关程度稍差(r=0.21～0.51)。结论MRA对近端血管无痉挛或者严重痉挛的检出率高,对远端轻度及中度痉挛患者的检出稍差。

Objective To evaluate the efficacy of MR angiogrphy（MRA） for detecting cerebral vasospasm after subarachnoid hemorrage （SAH） and compare it with spiral CT angiography （CTA）. Methods Ten patients with SAH under MRA and CTA studies were performed within 24 hours after MRA,which was performed 5 to 10 days after SAH. Maximum intensity projection（MIP） images were produced for MRA and CTA studies. Five arterial locations were examined for spasm： the suprasellar internal carotid artery（ ICA）, the M1 and M2 segments of the middle cerebral artery（MCA） ,the A1 and A2 segments of the anterior cerebral artery（ACA）. Vasospasm was categorized as none,mild （ 〈 30 % reduction）, moderate（30 % to 50 % reductidn）, or severe（ 〉 50 % reduction）. Results The overall correlation between MRA and CTA was 82 % （ r = 0.76 ）, but it was better for proximal than distal locations vessels. Agreement between MRA and CTA was greater for no spasm（89 % ） and severe spasm（ 100 % ） （ r = 0.85 -0.91 ） than for mild（56 % ） or moderate（67 % ） spasm（ r = 0.21 -0.51 ）. Conclusion MRA is highly accurate in the detecting no spasm or severe cerebral vasospasm in proximal arterial locations vessels; it is less accurate in detecting mild and moderate spasm in distal locations vessels.