Endo Hideki, Ono Hidetoshi, Ishida Yuki, Nakamura Hirohiko
Department of Neurosurgery, Nakamura Memorial Hospital, South 1, West 14, Chuo-ku, Sapporo, Hokkaido, 060-8570, Japan.
Department of Radiology, Nakamura Memorial Hospital, Sapporo, Hokkaido, Japan.
Surg Radiol Anat. 2025 Mar 17;47(1):99. doi: 10.1007/s00276-025-03594-z.
Although anatomical variations in the anterior cerebral artery (ACA), anterior communicating artery (ACoA) complex, and/or middle cerebral artery (MCA) are common, their combination is rare. Persistent primitive olfactory artery (PPOA) is a rare variant of the proximal ACA that has a hairpin curve associated with cerebral aneurysms. To our knowledge, there are no previous reports of PPOA associated with accessory MCA and partially duplicated ACoA.
We report a case of PPOA with a suspected aneurysm at the hairpin curve associated with accessory MCA and partially duplicated ACoA, diagnosed by 1.5-Tesla magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA).
A 46-year-old woman visited our hospital for screening examinations for cerebrovascular disease. MRA showed hairpin curves in the proximal portions of the bilateral ACAs, which we considered to be bilateral PPOAs (type 1). MRA three-dimensional volume rendering images revealed a small bulge, a suspected aneurysm, at the left hairpin curve. MRI/MRA showed that the left accessory MCA originated just proximal to the bulge in the hairpin curve. A partial duplication of the ACoA was also observed. We plan to follow up on the bulge in the hairpin curve because of the increased risk of aneurysm formation.
Careful imaging assessment is important to identify rare anatomical variations. MRA three-dimensional volume rendering images provided a better understanding of the vascular structure, including the presence of a small bulge suspected to be an aneurysm. In our case, accessory MCA was considered to enhance local hemodynamic stress at the hairpin curve.
虽然大脑前动脉（ACA）、前交通动脉（ACoA）复合体和/或大脑中动脉（MCA）的解剖变异很常见，但它们同时出现的情况却很罕见。永存原始嗅动脉（PPOA）是近端ACA的一种罕见变异，其呈发夹样弯曲并与脑动脉瘤相关。据我们所知，此前尚无PPOA合并副MCA和部分重复ACoA的报道。
我们报告了一例PPOA病例，其在与副MCA和部分重复ACoA相关的发夹样弯曲处疑似存在动脉瘤，通过1.5特斯拉磁共振成像（MRI）和磁共振血管造影（MRA）得以诊断。
一名46岁女性因脑血管疾病筛查来我院就诊。MRA显示双侧ACA近端呈发夹样弯曲，我们认为这是双侧PPOA（1型）。MRA三维容积再现图像显示在左侧发夹样弯曲处有一个小凸起，疑似动脉瘤。MRI/MRA显示左侧副MCA恰起源于发夹样弯曲处凸起的近端。还观察到ACoA存在部分重复。由于动脉瘤形成风险增加，我们计划对发夹样弯曲处的凸起进行随访。
仔细的影像学评估对于识别罕见的解剖变异很重要。MRA三维容积再现图像能更好地了解血管结构，包括疑似动脉瘤的小凸起的存在。在我们的病例中，副MCA被认为会增加发夹样弯曲处的局部血流动力学应力。
