Imaging description

In a previously healthy adult patient presenting with an acute to subacute myelopathy, first a compressive lesion such as a large disc extrusion or mass associated with bone metastasis should be ruled out. MRI is uniquely suited for the evaluation of these patients with its ability to evaluate the spine as well as the cord and nerve roots. Once an extrinsic compression is excluded a demyelinating, inflammatory, or neoplastic intrinsic cord lesion is usually responsible for the symptoms. An enhancing cord mass with associated edema and focal expansion of the cord is usually attributed to primary or secondary neoplasms, although a demyelinating plaque can have very similar features (Fig. 102.1). In about 10–20% of multiple sclerosis (MS) patients the first presentation is related to a solitary spinal cord lesion, most frequently in the cervical cord [1]. While most of these patients will have a relatively typical plaque with a focal T2 hyperintense lesion involving no more than 50% of the surface area of the cord on axial images and no longer than two vertebral body height on sagittal images, some patients may have an enhancing “mass” with associated edema and cord expansion (Fig. 102.2). Neuromyelitis optica is a separate demyelinating process of the cord associated with optic neuritis, and may present with similar imaging features. Acute transverse myelopathy is an immune-mediated inflammatory disorder of the cord with variable etiology that can present with enhancing cord lesions (Fig. 102.3).