PURPOSE Vertebral artery fenestration (VAF) is a rare congenital vascular anomaly which has been associated with intracranial aneurysm. VAF can share some similar imaging features with vertebral artery dissection (VAD), which may confound diagnosis of the latter on CT and MR angiography. The purpose of this investigation is to assess the prevalence of VAF, evaluate its association with other vascular anomalies, and identify imaging features to help in distinguishing VAF and VAD. METHODS Using keyword search on CTA and MRA head and neck imaging reports from 2010 to 2017, cases of VAF and VAD were retrospectively identified and imaging was reviewed. Imaging features including laterality; vertebral segment; length of affected segment; presence, number, and caliber of lumen(s); and presence of other vascular abnormalities were recorded for all cases and subsequently compared using Pearson's chi-squared test to assess for significant differences between the groups. Patient age, gender, and clinical presentations were also recorded. RESULTS Of 64,888 CT and MR angiographic examinations performed, VAF was identified in 67 (0.1%) and VAD in 54 (0.1%) patients. Compared with VADs, VAFs were shorter in length (p < 0.001), wider in luminal diameter (p < 0.001), more likely to occur at the V4 segment (p < 0.01), more likely to have two distinct lumens rather than one (p < 0.01), and less likely to present post-trauma (p < 0.01). Coexisting intracranial aneurysms were identified in 9% of patients with VAF. CONCLUSION VAFs, although rare, can be readily distinguished from VADs on angiographic imaging. Diagnosis of VAF should prompt review for intracranial aneurysm.

中文翻译：

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椎动脉开窗的影像学特征。

目的椎动脉开窗术（VAF）是一种罕见的先天性血管异常，与颅内动脉瘤有关。VAF可以与椎动脉解剖（VAD）共享一些相似的影像学特征，这可能会混淆CT和MR血管造影对后者的诊断。这项研究的目的是评估VAF的患病率，评估其与其他血管异常的关联，并确定影像学特征以帮助区分VAF和VAD。方法回顾性分析2010年至2017年CTA和MRA头颈影像学报告中的关键词，对VAF和VAD病例进行回顾性分析。成像特征包括偏侧性；椎段 受影响段的长度；流明的存在，数量和口径；记录所有病例的血管紧张度和其他血管异常的存在，随后使用皮尔森卡方检验进行比较，以评估两组之间的显着差异。还记录了患者的年龄，性别和临床表现。结果进行了64,888例CT和MR血管造影检查，其中67例（0.1％）发生了VAF，54例（0.1％）发生了VAD。与VAD相比，VAF的长度更短（p <0.001），管腔直径更宽（p <0.001），更可能在V4段发生（p <0.01），更有可能具有两个不同的内腔而不是一个（ p <0.01），并且不太可能出现创伤后（p <0.01）。在9％的VAF患者中发现了并存的颅内动脉瘤。结论VAF尽管很少见，但在血管造影成像中可轻易与VAD区分开。