Spinal-cord MRI in multiple sclerosis

The potential of MRI of the spinal cord as a diagnostic tool in MS has recently gained much interest. Dual echo spin echo MRI is most sensitive for the detection of spinal-cord abnormalities, which range from multiple focal lesions to confluent areas of high signal intensity. In some patients, commonly those with primary progressive disease, diffuse areas of slightly increased signal intensity are found. Disappointingly, the relation between MRI findings and clinical disability is weak. Studies relating MRI findings with histopathology have revealed substantial axonal loss in the spinal cords of patients with MS, whether focal lesions are present of not. Further, diffuse cord atrophy is found in advanced MS, which may reflect axonal loss. In the diagnostic setting, spinal-cord imaging is valuable. First, asymptomatic spinal-cord lesions are very rare in disorders other than MS. For example, in a patient with equivocal brain findings such as an elderly patient with vascular-ischaemic lesions, a normal spinal-cord examination can help rule out MS. Second, presence of asymptomatic spinal lesions may help confirm a diagnosis of MS when few or no brain lesions are present.