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.