FUNCTIONAL IMAGE OF DYNAMIC COMPUTED-TOMOGRAPHY IN DIAGNOSTIC AND PROGNOSTIC EVALUATION OF ISCHEMIC STROKE WITHIN THE 1ST 6 HOURS

Background and Purpose: It is important to make a diagnosis before a l ow-density area appears on computed tomography for appropriate managem ent of acute ischemic stroke. We report the diagnostic and prognostic usefulness of functional image of dynamic computed tomography for acut e ischemic stroke. Methods: Forty-seven patients with ischemic strokes within 6 hours of ictus underwent dynamic computed tomography in whic h functional images were obtained. These findings were compared with a ngiographic findings, follow-up computed tomography, and clinical outc ome. Results: The functional images were categorized into three groups : (1) cortical type: abnormalities on time to peak image and/or correc ted mean transit time image involving mainly cortical structures (29 c ases); (2) noncortical type: abnormalities on either or both images li mited to noncortical structures (7 cases); and (3) normal type: no abn ormalities on both images (11 cases). Cortical type as a diagnostic te st for arterial trunk occlusion had a good sensitivity (100%), specifi city (95%), and accuracy (98%). Infarction volume on follow-up compute d tomography correlated with extension of prolonged time-to-peak area (r=.80, P<.01) and that of prolonged corrected mean transit time area (r=.81, P<.01). Cortical type was associated with significantly unfavo rable outcome (P<.01). Conclusions: Functional image of dynamic comput ed tomography findings predicted arterial trunk occlusion, infarction volume, and clinical outcome. Therefore, this technique would be usefu l not only for indicating definitive angiography and subsequent therap y but for evaluating the effectiveness of surgical or medical recanali zation.