To evaluate the effectiveness of quality control circle (QCC) activities in improving the quality of carotid ultrasound images and reports.

From October 2024 to March 2025, the Ultrasound Department of Ningbo Integrated Traditional Chinese and Western Medicine Hospital conducted a QCC activity themed "Improving the Qualified Rate of Carotid Ultrasound Images and Reports". Before the intervention (March to August 2024), 90 carotid ultrasound examinations were randomly selected. QCC members scored image and report quality using relevant standardized indicators and calculated the qualified rate. Problems identified during the sampling were addressed through brainstorming, Pareto analysis, root cause analysis, goal setting, and targeted countermeasures, ultimately leading to the development of a standardized protocol. After the QCC activity (January to March 2025), another 90 examinations were randomly selected for effect confirmation. Qualified rates for images and reports were recalculated, and pre- and post-intervention differences were compared using the chi-square test. To assess sustainability, an additional 146 carotid ultrasound examinations were sampled within six months after the end of the QCC activity (August to September 2025).

After the QCC intervention, the qualified rate for carotid ultrasound images increased significantly from 46.7% (42/90) to 82.2% (74/90), and the qualified rate for reports rose from 63.3% (57/90) to 87.8% (79/90). Both differences were statistically significant (χ²=24.82, P＜0.001; χ²=14.59, P＜0.001). Six months after the end of the activity, the improvement was sustained, with qualified rates of 86.3% (126/146) for images and 84.2% (123/146) for reports, respectively.

QCC activities effectively improved the qualified rates of carotid ultrasound images and reports, with sustained benefits observed at six-month follow-up.