Department of Radiology, The Affiliated Hospital of Qingdao University, Qingdao 266003, China.
Department of Radiology, The Affiliated Hospital of Qingdao University, Qingdao 266003, China.
Acad Radiol. 2018 Dec;25(12):1564-1567. doi: 10.1016/j.acra.2018.01.025. Epub 2018 Mar 2.
The posterior inferior cerebellar artery aneurysm (PICAA), especially distal PICAA, is easily missed by a doctor, leading to misdiagnosis and treatment delays. The objective of this article is to report the computed tomography angiography (CTA) presentations of 30 cases of PICAA proved by digital subtraction angiography (DSA) or surgical operation, and analyze the causes of misdiagnosis of PICAA by CTA.
Thirty cases of patients with PICAA that were proved by DSA or surgical operation were included in this study, all of whom underwent CTA before surgical procedure. The relationship between the locations of PICAA and the rates of missed diagnosis by CTA was analyzed. The detection rates of the PICAA by volume rendering (VR) images and original thin axial images of CTA were compared.
Twelve cases (12 of 30, 40%) of aneurysm lied on the proximal end of posterior inferior cerebellar artery (PICA) (border with vertebral artery) and all of them (12 of 12,100%) were clearly displayed on the VR images of CTA and correctly diagnosed by doctors. Eighteen cases (18 of 30, 60%) of aneurysm lied on the distal part of the PICA, whereas only 2 of them (2/18, 11.1%) were displayed on the VR images and correctly diagnosed before surgical procedure. After surgical operation, the respective review of the CTA images demonstrated that all aneurysms (30 of 30, 100%) can be found on the thin axial images after careful observation and are shown on VR images after adjusting the display threshold when the locations of the PICAA through thin axial images were known, including the distal PICAA.
Thin axial CT images are most important and reliable for the detection of distal PICAA. Overdependence on three-dimensional VR images of CTA is the main cause of misdiagnosis.
小脑后下动脉动脉瘤（PICAA），尤其是远端 PICAA，容易被医生漏诊，导致误诊和治疗延误。本文旨在报告 30 例经数字减影血管造影（DSA）或手术证实的 PICAA 的计算机断层血管造影（CTA）表现，并分析 CTA 误诊 PICAA 的原因。
本研究纳入 30 例经 DSA 或手术证实为 PICAA 的患者，所有患者均在手术前接受 CTA 检查。分析 PICAA 位置与 CTA 漏诊率的关系。比较 CTA 容积再现（VR）图像和原始薄层轴位图像对 PICAA 的检出率。
12 例（30 例中的 12 例，40%）动脉瘤位于小脑后下动脉（PICA）近端（与椎动脉交界处），均在 CTA 的 VR 图像上清晰显示（12 例，100%），并被医生正确诊断。18 例（30 例中的 18 例，60%）动脉瘤位于 PICA 远端，其中仅 2 例（2/18，11.1%）在 VR 图像上显示，并在手术前正确诊断。手术后，仔细观察薄层轴位图像后，所有动脉瘤（30 例中的 30 例，100%）均可在薄层轴位图像上发现，且在已知 PICA 位置后调整 VR 图像的显示阈值，均可在 VR 图像上显示，包括远端 PICAA。
薄层轴位 CT 图像对远端 PICAA 的检测最为重要和可靠。过度依赖 CTA 的三维 VR 图像是误诊的主要原因。
