MR imaging of the brachial plexus: current imaging sequences, normal findings, and findings in a spectrum of focal lesions with MR-pathologic correlation.

Currently in many centers, magnetic resonance (MR) imaging is the technique of choice for the assessment of brachial plexopathies. The anatomy of the brachial plexus is complex, and is surrounded by other anatomic structures, making artifact-free imaging quite challenging. With the faster breathing-independent and breath-hold MR imaging sequences, brachial plexopathies can be assessed with more confidence. Over a 2-year period, 20 patients underwent MR imaging of the brachial plexus at our department. MR imaging was based on a comprehensive protocol, including T(1)-weighted gradient echo, T(2)-weighted single-shot fast spin-echo, and gadolinium-enhanced T(1)-weighted gradient echo with fat suppression. Nine of the 20 patients had proved diagnoses at pathology, and included schwannoma (n = 2), ganglioneuroblastoma (n = 1), hemangioma (n = 1), metastatic breast cancer (n = 2), Pancoast tumor (n = 1), and metastatic lung cancer (n = 2). Most of the lesions had presenting symptoms, such as pain, swelling, paresthesia, and arm weakness. At MR imaging, the location and characteristics of the lesions on different types of T(1)-weighted and T(2)-weighted sequences were described with pathologic correlation.