64层螺旋CT脑灌注成像和头颈部CT血管成像在颈内动脉和大脑中动脉狭窄和闭塞中的应用研究

A study on the application of CT perfusion and CT angiography with 64-slice spiral CT in the evaluation of internal carotid artery and middle cerebral artery stenosis and occlusion

目的评价64层螺旋 CT 脑灌注成像(CTP)和头颈部 CT 血管成像(CTA)检查对颈内动脉(ICA)及大脑中动脉(MCA)狭窄和(或)闭塞所致脑缺血的诊断价值。方法对69例经 DSA 证实为单、双侧 ICA 或 MCA 狭窄和(或)闭塞患者(病例组)及10名正常成年志愿者(对照组)分别进行64层螺旋 CT 头颅平扫、CTP 和 CTA 检查,观察 CTP 成像特点,并对各组脑血流量(CBF)、脑血容量(CBV)、平均通过时间(MTT)和达峰时间(TIP)进行定量分析。结果 CTA 诊断为单侧 ICA 狭窄和(或)闭塞的患者17例中,5例仅累及分水岭区,10例同时累及 MCA 供血区和分水岭区。单侧 ICA重度狭窄和(或)闭塞的灌注异常患者12例,非症状侧与症状侧的分水岭区 CBF 分别为(41±9)和(38±8)ml·100 g^(-1)·min^(-1),差异无统计学意义(t=2.08,P>0.05);MTT 分别为(5.2±1.1)和(10.9±2.6)s,差异有统计学意义(t=7.24,P<0.01)。CTA 诊断为双侧 ICA 重度狭窄和(或)闭塞的13例中,双侧 CTP 均表现为 MCA 供血区加分水岭区灌注缺损。25例单侧 MCA 狭窄患者,4例灌注正常;17例脑灌注缺损区为 MCA 供血区,4例为 MCA 供血区加分水岭区。12例双侧 MCA 重度狭窄的患者,灌注损伤区均为 MCA 供血区加分水岭区。结论 64层螺旋 CT 头颈部 CTA 联合应用脑CTP 检查,为 ICA 和 MCA 狭窄和(或)闭塞的临床治疗提供了更为详尽客观的影像依据。

Objective To evaluate clinical application of combined cerebral CT perfusion （CTP） with head and neck CT angiography （CTA） using 64-slice spiral CT on the cerebral ischemia caused by the stenosis or occlusion of internal carotid artery （ICA） and middle cerebral artery （MCA）. Methods The sixty nine patients with unilateral or bilateral ICA and MCA stenosis or occlusion confirmed by digital subtraction angiography underwent head plain CT scan, cerebral CTP, and head and neck CTA using 64-slice spiral CT. Ten normal adults served as control. To discriminate the ischemic foci, the parameter maps of cerebral blood flow （CBF）, cerebral blood volume （CBV）, mean transit time （MTT） and time to peak （TIP） were obtained. Results Among the patients with unilateral ICA stenosis or occlusion diagnosed by CTA, abnormal perfusion was found only in the watershed zone in 5 cases, both the MCA territory and the watershed zone were involved in 10 cases. Of 12 patients with severe unilateral ICA stenosis and occlusion, CBF values of the watershed zone in nonsymptmatic and symptomatic sides were （41 ± 9 ）and（ 38 ± 8 ）ml·100 g^-1·min^-1 respectively （ t = 2.08, P 〉 0.05 ）, the MTT values were （ 5. 2 ± 1.1 ） and （ 10. 9 ± 2.6 ） s, respectively （ t = 7.24, P 〈 0. 01 ）. Thirteen patients with severe bilateral ICA stenosis or occlusion diagnosed by CTA had perfusion abnormalities in the both the MCA territory and the watershed zone. Of 25 patients with unilateral MCA stenosis, 4 patients were normal in CT perfusion, 17 patients had perfusion abnormalities in MCA territory, and 4 patients had perfusion abnormalities in both MCA territory and the watershed zone. Twelve patients with severe bilateral MCA stenosis diagnosed by CTA had perfusion abnormalities in both the MCA territory and the watershed zone. Compared to normal control, the MTT and TIP were increased, the CBF was decreased, and the CBV in MCA territory and the watershed zone at the symptomatic side was increased. Conclusion The combined examination of CTP with CTA can provide adequate and accurate information for the diagnosis and treatment of middle cerebral artery and internal carotid artery stenosis or occlusion.