Department of Radiology, Saitama Sekishinkai Hospital, 2-37-20 Irumagawa, Sayama, Saitama, 350-1305, Japan.
Department of Radiology, Kan-Etsu Hospital, 145-1 Suneori, Tsurugashima, Saitama, 350- 2213, Japan.
Surg Radiol Anat. 2024 Nov 27;47(1):5. doi: 10.1007/s00276-024-03515-6.
To describe a case of large arterial ring formed by a duplicate origin of the right middle cerebral artery (MCA) associated with a frontal branch arising from the superior channel of the ring (main MCA) using magnetic resonance (MR) angiography.
An 81-year-old man with spinocerebellar degeneration underwent cranial MR imaging and MR angiography using a 1.5-Tesla scanner. MR angiography was performed using a standard 3-dimensional time-of-flight technique.
MR imaging showed cerebellar atrophy and multiple cerebral white matter lesions. Regarding family history, he was diagnosed with Machado-Joseph disease. On MR angiography, an anomalous artery arose from the lateral wall of the supraclinoid segment of the right internal carotid artery (ICA) and fused with the main MCA, forming a large arterial ring. Thus, the anomalous artery was diagnosed as a duplicate origin of the MCA and not a duplicated MCA. The frontal branch of the MCA arose from the superior channel of the arterial ring (main MCA).
This variation is called "segmental duplication of the MCA." However, this term may be confused with a duplicate origin or fenestration of the proximal M1 segment of the MCA. We report the first case of this combined variation diagnosed using MR angiography.
使用磁共振（MR）血管造影术描述一例由右侧大脑中动脉（MCA）双重起源形成的大动脉环，并伴有起源于环的优势通道（主 MCA）的额支。
一名 81 岁男性因脊髓小脑变性接受了头部磁共振成像和 1.5 特斯拉扫描仪的磁共振血管造影检查。MR 血管造影采用标准的 3 维时间飞跃技术进行。
MR 成像显示小脑萎缩和多发性脑白质病变。根据家族史，他被诊断为 Machado-Joseph 病。在磁共振血管造影上，异常动脉起源于右侧颈内动脉（ICA）的床突上段外侧壁，并与主 MCA 融合，形成一个大的动脉环。因此，异常动脉被诊断为 MCA 的双重起源，而不是 MCA 的重复。MCA 的额支起源于动脉环的优势通道（主 MCA）。
这种变异被称为“MCA 节段性重复”。然而，这个术语可能与 MCA 的近端 M1 段的双重起源或窗孔混淆。我们报告了首例使用磁共振血管造影术诊断的这种联合变异病例。
