多模式CT对缺血性卒中脑侧支循环的评估价值

Assessment value of multimodal CT for cerebral collateral circulation in ischemic stroke

目的探讨多模式CT检查对脑缺血后侧支循环的评估价值。方法对39例缺血性卒中患者入院3 d内行多模式CT检查,包括CT平扫、CT灌注(CTP)成像、CT血管成像(CTA),采用德国西门子64层螺旋CT系统的后处理软件,对受检者脑组织灌注状态及脑血管情况进行评估。对侧支循环良好者与侧支循环不良患者的CTP参数[脑血流量(CBF)、脑血容量(CBV)、平均通过时间(MTT)、平均达峰时间(TTP)]及出院后90 d改良Rankin量表(mRS)评分进行比较。结果 39例患者中,多模式CT检查阴性者2例,其中1例随访头部MRI,证实为短暂性脑缺血发作,1例为腔隙性脑梗死;阳性者37例。多模式CT检查发现病灶侧责任血管闭塞或狭窄24例,其中11例病灶侧可见侧支循环生成,另外13例患者病灶侧侧支循环形成不良。病灶侧与健侧比较,侧支循环良好患者表现为CBF降低(t=-5.92),MTT、TTP延长(t值分别为4.27、3.17),差异均有统计学意义(均P<0.01);侧支循环不良患者CBV、CBF均明显降低(t值分别为-14.27、-14.82),MTT、TTP延长(t值分别为7.26、7.54),差异均有统计学意义(均P<0.01)。两组患者病灶侧CBF、CBV、TTP差异均有统计学意义(t值分别为3.24、4.11、-2.34,均P<0.05)。侧支循环良好与不良患者90 d mRS评分分别为(1.3±0.6)、(4.0±0.9)分,差异有统计学意义(t=-8.29,P<0.01),有侧支循环形成的患者预后良好。结论多模式CT检查对于评估脑血流灌注状态、了解脑侧支循环建立或开放情况、判断临床预后具有一定临床意义。

Objective To investigate the assessment value of multimodal CT examination for collateral circulation after cerebral ischemia. Methods Within 3 days of admission,39 patients with ischemic stroke received multimodal CT examinations,including CT scan,CT perfusion（ CTP） imaging,and CT angiography（ CTA）. The postprocessing software of the German SIEMENS 64-slice spiral CT system was used to evaluate the state of brain tissue perfusion and the conditions of head blood vessels of the subjects. The cerebral blood flow（ CBF）,cerebral blood volume（ CBV）,mean transit time（ MTT）,time to peak（ TTP）and the score of the modified Rankin scale（ mRS） in the 90 d after discharge were compared between the patients with good collateral circulation and poor collateral circulation. Results Among 39 patients,multimodal CT examination revealed that 2 patients were negative,one of them was followed up by head MR and was clinically proven as transient ischemic attack,and the other was lacunar infarction. Thirty-seven patients were positive. Multimodal CT examination found 24 patients had offending vessels occlusion and / or stenosis on the lesion sides,the collateral circulation formation in 11 of them was observed on the lesion sides; another 13 patients had poor collateral circulation on the lesion sides. The comparison of lesion sides and contralateral sides,the patients with good collateral circulation showed the CBF decreased（ t =- 5. 92）,the MTT and TTP prolonged（ t = 4. 27 and 3. 17 respectively）. There were significant differences（ all P〈 0. 01）. The CBV and CBF in patients with poor collateral circulation were decreased significantly（ t =- 14. 27 and- 14. 82 respectively）,MTT and TTP prolonged（ t = 7. 26 and 7. 54 respectively）. There were significant differences（ all P〈 0. 01）. There were significant differences in CBF,CBV,and TTP on the lesion sides between the two groups of patients（ t = 3. 24,4. 11,and- 2. 34,respectively; all P〈 0. 05）.The 90 d mRS scores for patients with good collateral circulation and poor collateral circulation were 1. 3 ±0. 6 and 4. 0 ± 0. 9 respectively. There was significant difference（ t =- 8. 2 9,P〈 0. 0 1）. The patients of having collateral circulation formation had good prognosis. Conclusion Multimodal CT examination has certain clinical significance for evaluation of cerebral perfusion state,understanding the establishment or patency of cerebral collateral circulation,and determining the clinical prognosis.