Objective To explore the role of quality control circle in reducing the rate of extravasation during"bolus-type"intravenous injection of radiopharmaceuticals.Methods A total of 624 patients who underwent emission computed tomography(ECT)examinations were retrospectively selected as the pre-quality control circle use analysis group,125 patients who underwent ECT examinations were selected as the post-quality control circle use experiment group,and 70 patients were selected as the control group.This study applied the continuous quality improvement tools of the quality control circle,including grasping the current situation,selecting injection tools,personnel training,brainstorming,root cause analysis,key factor evaluation,true cause verification,strategy formulation and measure implementation,to continuously improve the quality of"bolus-type"radioisotope injection and reduce the rate of radiopharmaceuticals extravasation.Results In the experiment group,the rate of radioisotope extravasation after nurses performed"bolus-type"intravenous injection was 14.2％,compared to 33.3％in the control group,an improvement of 19％,and the situation of radiopharmaceuticals extravasation was significantly improved.Skillful use of quality improvement tools,especially in areas such as insufficient compression time,improper compression method,slow blood flow speed in fine blood vessels,and failed puncture,was crucial for radioisotope sur-face imaging.Conclusion Through continuous quality improvement by the quality control circle,this study successfully reduces the rate of extravasation during"bolus-type"intravenous injection of radiopharmaceuticals,reduces skin contamination,and improves the quality of nuclear medicine images,which is of great significance for improving the safety and diagnostic accuracy of nuclear medicine ECT examinations.