Vertebrobasilar artery dissection as an importance of vascular disease in the posterior fossa

为探讨颅内椎基底动脉夹层的临床和影像学特点，回顾性分析31例经椎动脉造影证实的颅内椎基底动脉夹层患者的临床和MRI表现。椎动脉造影显示双腔征11例（13支动脉），珠串征20例（28支动脉），年龄25 ~ 82岁，平均54.8岁。缺血性小脑和/或脑干病变的临床症状很常见，但在3例病例中，夹层是在调查无关疾病时偶然发现的。头痛是椎基底动脉夹层的唯一特异性临床表现，占55%。T1加权像上的壁内血肿被强调为一种特殊的MR表现。壁内血肿的阳性率为32%。在注射造影剂后，87%的患者在三维（3-D）破坏梯度回忆采集（SPGR）图像上发现了双腔。三维SPGR成像方法被认为是筛选椎基底动脉夹层的有用方法。颅内椎基底动脉夹层可能比以前认为的更常见。这些患者可能没有症状或只有轻微症状。后循环的神经放射学筛查需要MR检查，包括对比增强的3-D SPGR。血管造影可能是必要的颅内椎基底动脉夹层的确诊，因为发现壁内血肿的敏感性不令人满意。

To determine the clinical and neuroradiological features of intracranial vertebrobasilar artery dissection, the clinical features and magnetic resonance (MR) findings of 31 patients (20 men and 11 women) with intracranial vertebrobasilar artery dissections confirmed by vertebral angiography were analyzed retrospectively. The vertebral angiography revealed the double lumen sign in 11 patients (13 arteries) and the pearl and string sign in 20 patients (28 arteries).The patients ranged in age from 25 to 82 years (mean, 54.8 years). Clinical symptoms due to ischemic cerebellar and/or brainstem lesions were common, but in 3 cases the dissections were discovered incidentally while investigating an unrelated disorder. Headache, which has been emphasized as the only specific clinical sign of vertebrobasilar artery dissection, was found in 55% of the patients. Intramural hematoma on T1-weighted images has been emphasized as a specific MR finding. The positive rate of intramural hematoma was 32%. Double lumen on 3-dimensional (3-D) spoiled gradient-recalled acquisition (SPGR) images after the injection of contrast medium was identified in 87% of the patients. 3-D SPGR imaging methods considered useful for the screening of vertebrobasilar artery dissection.Intracranial vertebrobasilar artery dissection is probably much more frequent than previously considered. Such patients may present no or minor symptoms only. Neuroradiological screening for posterior circulation requires MR examinations including contrast-enhanced 3-D SPGR.Angiography may be necessary for the definite diagnosis of intracranial vertebrobasilar artery dissection, since the sensitivity of the finding of intramural hematoma is not satisfactory.