Department of Diagnostic Radiology, Saitama Medical University International Medical Center, 1397-1 Yamane, Hidaka, Saitama, Japan.
Neuroradiology. 2012 May;54(5):445-50. doi: 10.1007/s00234-011-0903-x. Epub 2011 Jul 6.
Fenestrations of cerebral arteries are most common in the vertebrobasilar (VB) system, and magnetic resonance (MR) angiographic studies of these variations are sparse.
We retrospectively reviewed MR angiographic images of 3,327 patients; images were obtained using two 1.5-T imagers and picked up fenestrations of the intracranial vertebral artery (VA), VB junction, and basilar artery (BA) for evaluation.
In 92 patients, we found 93 fenestrations (2.80%), which included 18 of the intracranial VA (0.54% prevalence), 6 of the VB junction (0.18%), and 69 of the BA (2.07%). Most VA fenestrations were large, and the posterior inferior cerebellar artery arose from the fenestrated segment in 10 patients (56%). Fenestrations of the VB junction were small and triangular. Sixty-five (94%) of the 69 BA fenestrations were located at the proximal segment and had small slit-like configurations. The anterior inferior cerebellar artery arose from the fenestrated segment in 27 patients (37%). We found 18 cerebral aneurysms in 16 (17%) of the 92 patients with fenestration but detected only one aneurysm at the fenestration.
The overall prevalence of fenestrations of the intracranial VB system was 2.77%. We found associated cerebral aneurysms relatively frequently but rarely at the fenestration.
脑动脉的窗孔最常见于椎基底动脉（VB）系统，针对这些变异的磁共振（MR）血管造影研究较为少见。
我们回顾性地分析了 3327 例患者的 MR 血管造影图像；使用两台 1.5T 成像仪获取颅内椎动脉（VA）、VB 交界处和基底动脉（BA）的窗孔图像进行评估。
在 92 例患者中，我们发现了 93 个窗孔（2.80%），其中包括 18 个颅内 VA（0.54%的发生率）、6 个 VB 交界处（0.18%）和 69 个 BA（2.07%）。大多数 VA 窗孔较大，10 例（56%）患者的后下小脑动脉从窗孔段发出。VB 交界处的窗孔较小，呈三角形。69 个 BA 窗孔中有 65 个（94%）位于近段，呈小裂隙状。27 例（37%）患者的前下小脑动脉从窗孔段发出。我们在 92 例有窗孔的患者中发现了 18 个脑动脉瘤，其中 16 例（17%）患者有动脉瘤，但仅在一个窗孔处发现了一个动脉瘤。
颅内 VB 系统的窗孔总体发生率为 2.77%。我们发现相关的脑动脉瘤相对常见，但很少发生在窗孔处。
