Cranial CT appearance of acute multiple sclerosis.

In acute multiple sclerosis, cranial computerized tomography (CT) may show periventricular and deep white matter contrast-enhanced lesions that are easier to see using 8 mm rather than 13 mm cranial CT sections. Follow-up studies show that the lesions evolve either to areas of density similar to the surrounding white matter or to low-density lesions. We presume they represent foci of active demyelination with extravasation of iodine through an altered blood-brain barrier. Enhanced cranial CT studies may be helpful in diagnosing acute multiple sclerosis and in following the course of the white matter lesions.