Cervical root avulsion - Magnetic resonance imaging findings and comparison of diagnostic accuracy between magnetic resonance imaging and conventional myelography

Purpose: The purpose of this study was to describe the magnetic resonance imaging (MRI) findings of cervical root avulsion and to compare the diagnostic accuracy of MRI with that of conventional myelography in patients with brachial plexus injury. Methods: Cervical spine MRI in 15 patients and conventional myelograms in 13 patients with cervical root avulsion were reviewed retrospectively. The MRI findings of avulsed roots were assessed in 42 roots of 15 patients in whom the injury had been confirmed by surgery or conventional myelography. In six surgically explored patients, the diagnostic accuracy of MRI was compared directly with that of conventional myelography. Results: The MRI features observed in 42 avulsed roots included focal. extradural CSF collection (pseudomeningocele) in 30 patients, focal thickening of the root in 20, and focal thickening of the dura in 8 patients. Magnetic resonance imaging demonstrated more pseudomeningoceles and provided more accurate information on other soft tissue injury than did conventional myelography. The sensitivity, specificity, and diagnostic accuracy of MRI for cervical root avulsion were 72.7%, 86.7%, and 80.8%, respectively, whereas those of conventional myelography were 83.3%, 100%, and 93.7%, respectively. Conclusions: At present, conventional myelography is superior to MRI in overall diagnostic accuracy for cervical root avulsion. However, technical refinements of MRI will enhance its diagnostic accuracy, so MRI may eventually obviate conventional myelography in patients with cervical root avulsion.