先天性颈内动脉缺如患者的影像学诊断

Imaging diagnosis of congenital absence of the internal carotid artery

目的探讨先天性颈内动脉缺如的就诊原因与影像学特点。方法报道4例先天性颈内动脉缺如患者并对以往相关文献总结分析。结果4例患者发病年龄35～53岁，中位发病年龄43．5岁。其中男性1例，女性3例，就诊原因分别为蛛网膜下腔出血（SAH）1例，短暂性脑缺血发作（TIA）1例，痫性发作1例，头晕并头痛1例。4例患者颈动脉血管造影均示单侧或双侧颈动脉未显影，颈内动脉管缺如并颅内血管发育异常，其中伴基底动脉及后交通动脉迂曲扩张者3例，伴动脉瘤者2例。结论先天性颈内动脉缺如在各年龄段均可发病，儿童及青少年以SAH为首发症状多见，中老年人以TIA起病多见。影像学表现为：（1）CT骨算法示颈内动脉管缺如；（2）CT血管造影（CTA）或磁共振脑血管造影示颈内动脉全程不显影；（3）合并多种血管发育异常，如异常分支、代偿性迂曲扩张、动静脉畸形、动脉瘤等。颈动脉CTA是诊断先天性颈动脉缺如的首选影像学手段。

Objective To discuss the clinical and radiological features of congenital absence of the internal carotid artery. Methods Four patients of the congenital absence of the internal carotid artery were reported and the clinical and radiological features were summarized by a review of the literature. Results Four patients were shown subarachnoid hemorrhage （SAH）, transient ischemic attack （TIA）, epilepsy and headache, respectively. All of the four patients presented the absence of unilateral or bilateral carotid arteries in cervical computed tomography angiography （CTA） or magnetic resonance angiography （MRA）. Carotid canal was absent in all the patients in CT base of skull and multiple intracranial vascular dysplasia was shown in all the patients. Basilar or posterior communicating artery was presented as dolichoectasia in 3 patients. There were 2 patients who suffered aneurysm. Conclusions The onset of the congenital absence of the internal carotid artery can be presented in any age. Sudden severe headache as initial symptom caused by SAIl is showed more common in children and adolescents. TIA is commonly seen in the elderly. CT shows carotid canals are absent in the base of skull. Unilateral or bilateral carotid arteries are shown absent in CTA or MRA. Multiple intracranial vascular dysplasia is shown in CTA or MRA. Carotid artery CTA has been considered as the optimal imaging method of showing the congenital absence of the internal carotid artery.