Effect of smoothing brain scans: a study using receiver operating characteristic curves

A sample of computed tomography (CT) brain scans containing marginal lesions with different degrees of spatial smoothing was shown to two groups of observers. One group consisted of radiologists who had considerable experience in the interpretation of CT brain scans, whereas those in the other group had only limited experience. Neither group showed any significant change in ability to detect the marginal lesions when the pictures were smoothed. The groups were able to make diagnostic decisions even on pictures with high degrees of smoothing.