In this issue of the Archives, Capra et al1 report the results of biweekly magnetic resonance imaging (MRI) in 10 patients with relapsing-remitting multiple sclerosis (MS). A total of 93 gadolinium-pentetic acid (GdDTPA)-enhancing lesions were observed in eight patients studied during a 3-month period. Of the enhancing lesions, 88% were in the supratentorial white matter, 9% were in the brain stem or cerebellum, and 3% were in the cervical spinal cord. Seventy percent of the lesions occurred in T2-weighted hyperintense areas already found in previous examinations. Excluding each patient's first and last scan, 64 newly enhancing lesions were observed. In 50% of the newly enhancing lesions, Gd enhancement was no longer evident on the subsequent scan, suggesting that the duration of enhancement was 4 weeks or less. Seven clinical relapses occurred in six patients, all with concurrent Gd enhancement. Gadolinium-enhancing lesions were noted in 18 MRI examinations