This composite educational graphic illustrates the normal anatomy of the brachial plexus through anatomical diagrams and Magnetic Resonance Imaging (MRI). Panel A is an anatomical diagram depicting the plexus architecture from roots (C5-T1) to terminal branches, labeled with musculoskeletal landmarks like the scalene muscles and coracoid process. Panel B (axial) and Panel C (sagittal) are T1-weighted MRI scans demonstrating the interscalene triangle, defined by the anterior scalene (sa) and middle scalene (sm) muscles. These muscles serve as primary radiological landmarks for identifying the neural roots and trunks (indicated by arrows). Panel D provides an oblique coronal T1-weighted MRI view, tracing the sequential segments of the right brachial plexus: roots (R), trunks (T), divisions (D), and cords (C). This resource is designed for medical education in radiology and neurology to assist in the localization of neural structures and the diagnostic evaluation of conditions like brachial plexopathy, neurogenic tumors, or Pancoast tumors.

This composite educational resource comprises three Magnetic Resonance Neurography (MRN) coronal views (a, b, c) and a correlating schematic anatomical diagram (d) illustrating a severe traumatic brachial plexus injury. The right side of the images displays normal brachial plexus anatomy, with continuous nerve structures including the upper trunk (1), middle trunk (2), C8 root (3), and Th1 root (4). In contrast, the left side demonstrates a total rupture of the brachial plexus (dashed arrows). This injury is characterized by the complete discontinuity of the neural trunks and cords, accompanied by a large axillary cavity hematoma (curved dashed arrows). The schematic (d) highlights the side-to-side difference, showing the organized right-sided roots (C5-Th1) and trunks versus the disorganized, hemorrhagic area on the left. This material is designed for advanced medical education in radiology and neurosurgery, focusing on diagnostic imaging features of high-grade nerve trauma, specifically Seddon grade 3-5 injuries (neurotmesis) and the identification of postganglionic plexopathy.

This composite educational graphic details the anatomy of the human brachial plexus (BP) through cadaveric dissections and a schematic diagram. (A) Cadaveric dissection of the cervical spine and axilla with the anterior scalene muscle removed, exposing the C5-T1 nerve roots emerging laterally to the middle scalene muscle (MS). (B) A structured schematic diagram illustrating the hierarchical organization of the BP from roots (C5-T1), trunks (Superior, Middle, Inferior), divisions (Anterior, Posterior), and cords (Lateral, Posterior, Medial) to terminal branches. (C) Dissection showing the roots in situ within the scalene triangle, formed between the anterior (AS) and middle scalene muscles, alongside major vessels including the subclavian artery (SCA) and internal jugular vein (IJV). The phrenic nerve (yellow arrowhead) is seen traversing the anterior scalene. (D) Detailed view of the infraclavicular and axillary regions showing terminal branches (1-8: suprascapular, musculocutaneous, axillary, radial, medial brachial cutaneous, median, ulnar, and intercostobrachial nerves) in relationship to the pectoralis minor (Pmi), pectoralis major (Pma), and subclavian vessels. This content provides essential topographical and clinical anatomy for understanding thoracic outlet syndrome and regional anesthesia.