Abstract:

Objective To explore the clinical value of multimode computed tomography (CT) in the assessment of isolated posterior circulation ischemia vertigo. Methods The 320-slice whole-brain computed tomography perfusion (CTP), head and neck computed tomography angiography (CTA) were performed in 30 patients with clinical diagnosed isolated posterior circulation ischemia vertigo. The intracranial and extracranial arteries of the posterior circulation and the whole brain perfusions were observed. Results Vascular lesions were found in 25 patients (83.33%), among which, 70 vessels were vertebrobasilar stenosis, 9 vessels were vertebral artery circuity, and 4 were vertebral artery hypoplasia. Abnormal perfusions were found in 22 patients (73.33%), time to peak (TTP) and mean transit time (MTT) were prolonged in 20 and 17 patients respectively, and cerebral blood flow (CBF) and cerebral blood volume (CBV) were reduced in 16 and 13 patients respectively. Responsible artery stenosis was found in all of the patients with abnormal perfusions, and 15 of which were moderate/severe stenosis. TTP and MTT of the affected side significantly were prolonged compared with the contralateral side (P <0.05), but no significant difference of CBV nor CBF was detected between the affected side and the contralateral side. Perfusion abnormalities associated with the degree of responsible artery stenosis. Positive incidence of CTP abnormalities was higher in patients with moderate/severe vascular stenosis than in those with mild/none vascular stenosis (P <0.05). Conclusion Multimode CT is effective to assess the brain vessels and perfusions of patients with isolated posterior circulation ischemia vertigo.

Key words: Isolated vertigo; Posterior circulation ischemia; CT perfusion; CT angiography; Multimode CT

摘要：

目的 探讨多模式计算机断层扫描（computed tomography，CT）在后循环缺血性孤立性眩晕中的应用价值。 

方法 对30例临床诊断为后循环缺血性孤立性眩晕患者进行320排CT全脑灌注成像（computed tomography perfusion，CTP）及头、颈部CT血管成像（computed tomography angiography，CTA）检查，观察后循环缺血性孤立性眩晕患者颅内外血管状况及脑灌注情况。 

结果 25例（83.33%）患者存在血管病变，其中70条椎基底动脉硬化并狭窄，9条椎动脉起始部扭曲，4条椎动脉先天发育不良。22例（73.33%）患者CTP图上发现与临床症状相对应的灌注异常区，达峰时间（time to peak，TTP）延迟及平均通过时间（mean transit time，MTT）延迟者分别为20例和17例， 发现脑血流量（cerebral blood flow，CBF）下降及脑血容量（cerebral blood volume，CBV）下降者分别为 16例和13例。22例CTP异常的患者患侧均存在责任血管狭窄，其中15例患者血管病变为中、重度狭窄。 灌注异常区的TTP及MTT值高于健侧镜像区（P＜0.05），患侧与健侧的CBF及CBV比较未发现存在明显 差异；CTP异常与责任血管狭窄程度具有相关性，责任血管中、重度狭窄者CTP异常阳性率高于责任血 管轻度狭窄者及无狭窄者（P＜0.05）。

结论 多模式CT可对后循环缺血性孤立性眩晕的患者血管状况及血流动力学进行有效评价。

关键词: 孤立性眩晕; 后循环缺血; CT灌注成像; CT血管成像; 多模式CT