ASSESSMENT OF INTRAAXIAL AND EXTRAAXIAL BRAIN-LESIONS WITH DIGITIZED COMPUTED TOMOGRAPHIC-IMAGES VERSUS FILM - ROC ANALYSIS

Rationale and Objectives. The authors evaluated the diagnostic accurac y of viewing computed tomographic (CT) scans as film versus soft-copy images at a workstation. Methods. Receiver operating characteristic an alysis of the interpretation of 202 CT scans (103 were normal, 99 were abnormal) by five neuroradiologists was performed. Abnormal images co ntained high- or low-attenuation intraaxial lesions or extraaxial flui d (subdural, subarachnoid, or epidural hemorrhage). Hard copies were r ead on a standard light box, and digital images were examined at a 1,0 24 x 1,250 workstation. Lesion location and type and confidence rating s were recorded on a worksheet. Results. There were no statistically s ignificant differences in diagnostic accuracy between the two display modes. Reader performance was slightly better with the workstation in the assessment oflow-attenuation lesions. Conclusion. Diagnostic accur acy is similar for CT scans displayed at a workstation and those displ ayed as hard copy in the assessment of subtle intra- and extraaxial br ain lesions.