Radiation dose monitoring in pediatric fluoroscopy: comparison of fluoroscopy time and dose-area product thresholds for identifying high-exposure cases.

BACKGROUND: Fluoroscopy time has been used as a surrogate for radiation dose monitoring in pediatric fluoroscopy; however it does not account for factors such as magnification or collimation. Dose-area product (DAP) is a more accurate measure of radiation exposure but its dependence on patient weight and body-part thickness is a challenge in children of varying ages. OBJECTIVE: To determine whether fluoroscopy time and DAP produce concurrent results when they are used to identify high-exposure cases, and to establish radiation dose thresholds for our institution. MATERIALS AND METHODS: During a 2-year period we prospectively monitored pediatric fluoroscopy studies performed at the Children's Hospital at Montefiore. We recorded study type, fluoroscopy time, DAP, patient age, weight and height. We then calculated 90th percentile fluoroscopy time and DAP thresholds for weight and age. RESULTS: We evaluated 1,011 cases (453 upper gastrointestinal [UGI] series, 266 voiding cystourethrograms [VCUGs], 120 contrast enemas, 108 speech studies, and 64 esophagrams). Fluoroscopy time demonstrated moderate correlation with DAP (rs=0.45, P<0.001, Spearman rank). DAP strongly correlated with patient weight (rs=0.71, P<0.001) and age (rs=0.70, P<0.001). Concordance of cases exceeding 90th percentile thresholds for fluoroscopy time and DAP were κ=0.27 for UGI series and κ=0.49 for VCUG for weight-based cutoffs, and κ=0.36 for UGI series and κ=0.40 for VCUG for age-based cutoffs. CONCLUSION: The limited correlation of fluoroscopy time with DAP suggests these methods are not equivalent for dose monitoring. However, the strong correlation of DAP with patient weight and age presents a challenge for establishing DAP thresholds in children, who range widely in size. Despite controlling for weight or age, there was limited overlap of cases exceeding the 90th percentile threshold for fluoroscopy time and DAP. This further reinforces the non-overlapping outcome of these two methods and indicates that fluoroscopy time might be inadequate for dose monitoring.

A radiologist's guide to the clinical scales used in the 2015 Endovascular Stroke Trials and the Revised American Heart Association/American Stroke Association Guidelines for Endovascular Stroke Treatment.

In 2015, five trials demonstrated the efficacy of endovascular treatment for acute stroke, culminating in the revised American Heart Association/American Stroke Association (AHA/ASA) recommendations for stroke management. The different clinical scales used in these trials may be unfamiliar to emergency and on-call radiologists. The modified Rankin Scale was used to describe patient disability for prestroke assessment in three of the trials and for the 90-day follow up in all five trials. The Barthel index was used in one trial to score prestroke ability to perform activities of daily living. The NIH Stroke Scale was used as part of eligibility criteria in four of the stroke trials to assess pre-existing neurological deficits. Also, the modified Rankin Scale and the NIH Stroke Scale are used in the revised AHA/ASA recommendations. By understanding these scales, emergency and on-call radiologists will better appreciate the stroke patient's condition and will be able to more actively collaborate in the care of acute stroke patients.