Hyman R A, Black K S
Cornell University Medical College, New York, New York.
Top Magn Reson Imaging. 1989 Dec;2(1):49-62.
Intracranial aneurysms and vascular malformations are frequently detected following intracranial hemorrhages. A CT scan is the most sensitive method of detecting acute subarachnoid, parenchymal, and intraventricular hemorrhages. Small aneurysms are inconsistently visualized on MR scans. Angiography remains the standard for complete and accurate depiction of patent aneurysms, as well as of arteriovenous and venous malformations that have not thrombosed. Giant and thrombosed aneurysms present as mass lesions and are frequently detected when MR is used as a screening examination. Often MRI characterizes these lesions better than CT or angiography. Patients with vascular malformations who have focal neurologic symptoms without hemorrhage are best evaluated with MRI. Patent vascular malformations demonstrating flow void and other flow-related phenomena are readily demonstrated. Occult vascular malformations, including thrombosed arteriovenous, venous, and cavernous malformations and telangiectasia, are also best detected by MRI and are not visible on angiography.
颅内动脉瘤和血管畸形常在颅内出血后被发现。CT扫描是检测急性蛛网膜下腔、脑实质和脑室内出血最敏感的方法。小动脉瘤在磁共振成像（MR）扫描中显示不一致。血管造影术仍然是完整、准确描绘未血栓形成的动脉瘤以及动静脉和静脉畸形的标准方法。巨大动脉瘤和血栓形成的动脉瘤表现为占位性病变，当使用MR作为筛查检查时经常被发现。通常，磁共振成像（MRI）对这些病变的特征描述比CT或血管造影更好。有局灶性神经症状但无出血的血管畸形患者，最好用MRI进行评估。显示血流空洞和其他血流相关现象的未血栓形成的血管畸形很容易被发现。隐匿性血管畸形，包括血栓形成的动静脉、静脉和海绵状畸形以及毛细血管扩张，也最好通过MRI检测，在血管造影中不可见。
