We described specific MRI features of MS presenting with acute partial transverse myelopathy. We reviewed the clinical histories and MRI studies of brain and spinal cord of 24 patients, using axial and sagittal images of the spinal cord to define patterns of signal abnormality in the context of clinical presentation, course, and vertebral column structural pathology. The heterogeneity of spinal cord tract involvement was greater than previously reported, with signal abnormality identified within the central cord, crossing the gray-white junction, and involving all four major funiculi. Correlation between spinal cord MRI findings and neurologic deficits was strong (100% by axial images; 96% by sagittal images). Serial spinal cord MRI demonstrated the dynamic nature of the signal abnormalities over time and in response to high-dose steroid treatment. No cranial MRI abnormality initially was seen in 36% of cases with evidence of demyelinating disease on concurrent spinal MRI.