Use of CT dose notification and alert values in routine clinical practice

The purpose of this investigation was to assess the impact on workflow of the use of notification and alert values in our practice and to provide baseline data for quality improvement initiatives.

Five diagnostic clinical CT scanners were programmed with the notification and alert values recommended by the American Association of Physics in Medicine. Retrospective analysis was performed on log files to assess the frequency of and reason for notification and alert events.

Between February and September of 2012, 11,384 patients were scanned on the 5 systems. One alert occurred because of the use of bolus tracking in a morbidly obese patient, where the prescan cumulative volume CT dose index for the exam exceeded the recommended alert value of 1,000 mGy. Only 1.2 ± 0.6% of patient scans triggered a notification. Notifications were mainly triggered because of bolus tracking and/or large patient size. Protocols triggering notifications most often included CT angiography of the chest for pulmonary emboli.

Because only a small percentage of performed patient examinations triggered a notification or alert event, the impact on workflow of adopting these features was negligible. Evaluation of the logs identified trends in reasons for which notification events were triggered; these primarily included large patient size and bolus tracking. Additionally, specific protocols were identified where adjustment of notification values was deemed necessary.