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

为了确定颅内椎基底动脉夹层的临床和神经影像学特征，回顾性分析经椎动脉造影证实的31例（男20例，女11例）颅内椎基底动脉夹层的临床特征和磁共振（MR）表现。椎动脉造影显示双腔征象11例（13条动脉），珍珠串征象20例（28条动脉）。患者年龄25 ~ 82岁（平均54.8岁）。由于缺血性小脑和/或脑干病变引起的临床症状是常见的，但有3例解剖是在调查不相关疾病时偶然发现的。头痛被强调为椎基底动脉夹层的唯一特异性临床征象，55%的患者出现头痛。t1加权图像上的壁内血肿被强调为一种特殊的MR发现。颅内血肿阳性率为32%。在注射造影剂后的三维（3-D）破坏梯度回忆采集（SPGR）图像上，87%的患者被识别出双腔。三维SPGR成像方法被认为是筛查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频繁。这类患者可能只出现轻微或无症状。后循环的神经放射学筛查需要MR检查，包括增强的3-D SPGR。血管造影对于颅内椎基底动脉夹层的明确诊断可能是必要的，因为血管内血肿的发现敏感性并不令人满意。

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.