[MR imaging of carbon monoxide intoxication: evaluation of 13 cases to discuss the relation between MR findings and clinical course].

MR images of the brain were retrospectively reviewed in 13 patients with carbon monoxide (CO) poisoning to examine the relation between the MR findings and clinical course. The patients included 11 men and 2 women whose ages ranged from 6 to 88 years (mean, 38 years). Repeated MR studies of at most five times were performed on 9 patients. Lesions in the bilateral globus pallidi were found in 5 cases showing hyperintensity on T2-weighted images (T2WI) and iso-to hypointensity on T1-weighted images (T1WI). The patients with only pallidi lesions clinically recovered well. Hyperintense white matter lesions were recognized on T2WI in 8 patients, including all 5 with delayed encephalopathy. Sequential studies generally showed a tendency of regression of these hyperintense lesions with improvement of symptoms, indicative of reversible demyelination as documented in the pathological literature. One patient with poor prognosis revealed white matter lesions, that were hyperintense on T2WI and very hypointense on T1WI, which may represent irreversible change. Thus, clinical course seems to be closely related with white matter lesions, but not with pallidi lesions. In cases of CO intoxication, therefore, MR study provides valuable information on patients' clinical prognoses.