Evaluation of emergency CT scans of the head: is there a community standard?

This study was designed to assess the accuracy of general radiologists in the interpretation via teleradiology of emergency CT scans of the head.

We studied the interpretations of 716 consecutive emergency CT scans of the head by a group of 15 board-certified general radiologists practicing in the community (as opposed to an academic setting). The scans were sent via teleradiology, and the preliminary interpretations were made. Three of the general radiologists were functioning as nighthawks, and the remaining 12 were acting as on-call radiologists in addition to their normal daytime duties. Each CT examination was interpreted by one of five neuroradiologists the day after the initial interpretation had been performed. The findings of the final interpretation and the preliminary interpretation were categorized as showing agreement, insignificant disagreement, or significant disagreement. The reports in the two categories indicating disagreement were reviewed and reclassified by a consensus of three university-based neuroradiologists.

Agreement between the initial interpretation by the general radiologist and the final interpretation by the neuroradiologist was found in 95% of the CT scans. The interpretations were judged to show insignificant disagreement in 3% (23/716) of the scans and to show significant disagreement in 2% (16/716). Of the 16 significant errors, five were false-positive findings and 11 were false-negative findings. Forty-seven CT scans depicted significant or active disease, and in 11 (23%) of these scans, the final report differed significantly from the preliminary interpretation. Three patients had pituitary masses, none of which had been described on the preliminary interpretation.

The rate of significant discordance between board-certified on-call general radiologists and neuroradiologists in the interpretation of emergency CT scans was 2%, which was comparable to previously published reports of residents' performance. The pituitary gland may be a blind spot, and additional attention should be focused on this area.