Optimizing Radiation Dose: UW–Madison’s Experience with the ACR Learning Network ImPower Program

Purpose: For over a decade, our institution has tracked radiation dose relative to patient size on a single-vendor CT fleet. Recognizing the need to extend these advancements to a newly acquired CT scanner, our team embarked on a harmonization project.

Methods/Materials: We tracked routine abdomen pelvis radiation dose on a GE and a new Canon Medical Systems scanner. On the Canon scanner, we observed elevated radiation dose, prompting the need for change. Supported by the American College of Radiology (ACR) Dose Optimization project (i.e., ImPower Program), we embarked on a quality project to identify and address the root causes of these discrepancies. Employing a structured, lean-based problem-solving approach (A3 thinking), we conducted Gemba walks to observe CT technologists, developed fishbone diagrams for root cause analysis, and identified key drivers influencing dose variability. We had 2 radiologists perform a reader study on 30 different patients (15 GE, 15 Canon) using Likert scoring for diagnostic utility before and after dose interventions.

Results: We quantified dose versus size four times during the study: pre, after the first, after the second intervention, and continuing monitoring. The first intervention changed the level of deep learning-based image denoising, which decreased patient dose. The second intervention increased the AEC setting of noise which also decreased patient dose. Patient dose curves were found to decrease after the first and second interventions, no change was observed between the second intervention and continuing monitoring period. At the end of the study, no difference was observed between radiologists Likert scores between the scanners.

Conclusions: Our study underscores the importance of quantifying radiation dose relative to size when harmonizing Automatic Exposure Control (AEC) settings across different platforms. Without plotting patient dose against size, accurately identifying and rectifying dose discrepancies between scanners would have been challenging. The quality processes our teamed learned as part of the ACR ImPower program guided our efforts through a complex iterative process.