UTILITY OF REPEAT BRAIN IMAGING IN STROKE

PURPOSE: To determine the utility of repeat brain imaging in patients with stroke. METHODS: We reviewed the medical records of 98 consecutiv e patients in whom stroke was diagnosed between January 1 and December 31, 1991. We noted the number of brain scans performed, the indicatio ns cited, and whether repeat imaging changed the therapeutic decisions or final diagnosis. RESULTS: Ninety-eight patients underwent 221 proc edures, with 123 repeat imaging studies (98 CT scans and 25 MR images) , Sixteen patients had only one scan; 51 had two, and 31 had three or more. Indications for repeat imaging were explicitly documented in 62 (50%) of 123 repeated scans and inferred in another 41 (33%). In 20 (1 6%), no definite indication could be determined. Indications included lack of acute abnormal imaging findings on the initial scan (n = 48, 3 9%); compliance with stroke research protocol (n = 24, 20%); lack of c orrelation between clinical examination and initial radiologic finding s or concern that tumor was mimicking infarction (n = 20, 16%); and ne urologic deterioration (n = 11, 9%), In none of the 82 patients did th e repeated scan change the diagnosis; therapy was changed in only two (2%) of 82 patients (aspirin was discontinued). CONCLUSIONS: Repeat im aging in patients rarely results in changes in the initial diagnosis o r the therapeutic plan; indications for repeat imaging are frequently not clearly stated; in certain groups of patients with stroke, repeat imaging may not be useful.