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

Wang Wuhua; Deng Xiaochun; Hu Ling

doi:10.3969/j.issn.1672-5921.2016.02.003

Abstract：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. 29,P <0. 01). 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.