Department of Radiology, Stanford University, School of Medicine, 300 Pasteur Drive, Stanford, CA, 94305, USA.
Division of Musculoskeletal Radiology, Department of Radiology, Stanford University, School of Medicine, 300 Pasteur Drive, Stanford, CA, 94305, USA.
Eur Radiol. 2021 Jun;31(6):3555-3563. doi: 10.1007/s00330-020-07476-3. Epub 2020 Nov 24.
Most of the shoulder magnetic resonance imaging (MRI) examination focuses on internal joint structures but disregarding other structures like the distal brachial plexus, which may miss important findings. Hereby, we attempt to evaluate the prevalence of distal brachial plexus abnormalities and/or muscular denervation changes seen on routine shoulder MRI examinations and discuss common pathologies affecting the distal brachial plexus.
A total of 701 routine shoulder MRI studies were evaluated. The evaluation of each exam was focused on the visualized brachial plexus elements and musculature abnormalities in each case. If any abnormalities of plexus and/or musculature were found, potential underlying etiologies such as paralabral or spinoglenoid notch cysts, infiltrative/primary masses on imaging, history of prior viral illness, and radiation therapy were searched. It was then confirmed whether the abnormal findings were mentioned in the exam reports or not.
Thirty-four cases (4.85%) demonstrated abnormal findings of the visualized brachial plexus cords or branches and/or musculature. It was observed that in 35.3% of exam reports these findings were not mentioned, mainly missing subtle nerve abnormalities, but correctly reporting and interpreting the encountered muscle abnormalities.
The distal brachial plexus and its branches should be included in the search pattern for shoulder MRI examinations.
• Normal T2 signal of the brachial plexus is iso- to slightly hyperintense to muscle but less signal intense than fluid. • Diffuse, geographic muscle edema is an indirect sign of brachial plexus pathology. • Increased T2-weighted nerve signal with or without caliber or course change should be reported and followed up to find the underlying etiology.
大多数肩部磁共振成像（MRI）检查侧重于内部关节结构，但忽略了其他结构，如远端臂丛，这可能会遗漏重要的发现。因此，我们试图评估常规肩部 MRI 检查中远端臂丛异常和/或肌肉失神经改变的发生率，并讨论影响远端臂丛的常见病变。
共评估了 701 例常规肩部 MRI 研究。对每例检查的评估重点是每个病例中可见的臂丛神经束和肌肉异常。如果发现臂丛神经和/或肌肉有任何异常，如果发现潜在的病因，如滑囊或肩胛上神经切迹囊肿、影像学上的浸润性/原发性肿块、先前的病毒感染史和放射治疗史等，则进行进一步检查。然后确认检查报告中是否提到了异常发现。
34 例（4.85%）表现出可见臂丛神经束或分支和/或肌肉的异常。观察到 35.3%的检查报告中未提及这些发现，主要是遗漏了细微的神经异常，但正确报告和解释了遇到的肌肉异常。
远端臂丛及其分支应包括在肩部 MRI 检查的搜索模式中。
臂丛的 T2 信号正常为与肌肉等信号到稍高信号，但比液体信号弱。
弥漫性、局灶性肌肉水肿是臂丛病变的间接征象。
应报告并随访 T2 加权神经信号的增加，伴有或不伴有口径或走行改变，以寻找潜在病因。
