Utilization guidelines for reducing radiation exposure in the evaluation of aneurysmal subarachnoid hemorrhage: A...

The purpose of this study was to reduce the cumulative radiation exposure from CT of patients with aneurysmal subarachnoid hemorrhage.

Baseline data on 30 patients with aneurysmal subarachnoid hemorrhage were collected retrospectively for all CT examinations of the head performed throughout the hospital course. Radiation exposure estimates were obtained by recording dose-length products for each examination. As a departmental practice quality improvement project, an imaging protocol was implemented that included utilization guidelines to reduce radiation exposure in CTA and CT perfusion examinations performed to detect vasospasm in patients with aneurysmal subarachnoid hemorrhage. Ten months after implementation of this protocol, data on 30 additional patients were analyzed. Means, medians, and SD estimates were compared for cumulative radiation exposure and absolute numbers of each examination.

Sixty patients were included in the study: 30 patients at baseline and 30 patients after implementation of the quality improvement plan. These patients underwent 435 CT examinations: 248 examinations at baseline and 187 examinations with the new protocol. With the new algorithm, the mean number of CT examinations per patient was 5.8 compared with 7.8 at baseline, representing a decrease of 25.6%. The number of CT perfusion examinations per patient decreased 32.1%. Overall, there was a 12.1% decrease in cumulative radiation exposure (p > 0.05).

With the structured imaging algorithm, the cumulative radiation exposure and number of CT examinations of the head decreased among patients with aneurysmal subarachnoid hemorrhage because utilization guidelines defined the appropriate imaging time points for detection of vasospasm. Application of these methods to other patient populations with high use of CT may reduce cumulative radiation exposure while the clinical benefits of imaging are maintained.