Thoracic myelopathy due to ossification of the posterior longitudinal ligament shown on dynamic MR.

Magnetic resonance (MR) and computed tomography (CT) studies combined are the optimal studies for diagnosing thoracic ossification of the posterior longitudinal ligament (OPLL) contributing to myelopathy. Here, we report a 71-year-old female, whose additional dynamic thoracic MR demonstrated transient T6-T9 anterior OPLL with cord compression.A 71-year-old female presented with a progressive myelopathy originally attributed to cervical cord compression resulting in a cervical laminoplasty. However, when she failed to improve postoperatively, a dynamic thoracic MR was performed. On the flexion study, it demonstrated significant although transient T6-T9 anterior thoracic cord compression due to both OPLL and kyphosis. The patient's symptoms resolved following a posterior thoracic fusion alone (i.e., no decompression was warranted).Dynamic MR studies (i.e., flexion studies) in addition to the routine MR and CT evaluations should be performed for patients with myelopathy attributed to thoracic OPLL/kyphosis.