lusionsThe CEUS findings are different between benign and malignant gallbladder adenomas. The enhancement pattern and speed are useful for differentiating benign from malignant adenomas.

Objective To investigate the frequency and dose of X-ray computed tomography (CT) medical exposure in Shantou City, and to evaluate the collective effective dose burden of residents caused by CT medical exposure. Methods The study subjects were selected using the stratified random sampling method from CT scanners in all medical institutions in Shantou City in 2020. CT application units were divided into the four tiers of municipal hospitals, district hospitals, subdistrict hospitals, and private hospitals, and 50% of the hospitals in each tier were randomly selected according to the number of hospitals in the tier. The study analyzed CT dose index results, CT scanning standard conditions, and the distribution of characteristic doses of medical exposure to evaluate the dose burden of residents in Shantou City caused by CT medical exposure. Results There were 51 CT scanners in medical institutions in Shantou City. By the end of 2020, the average number of CT scanners per million population was 9.30, and the frequency of CT medical exposure was 135.24 per 1000 population. Jinping District had the highest number of CT scanners per million population (23.2), while Chaoyang District had the lowest number of CT scanners per million population (3.6). The median and range of effective doses for different scan regions were 1.65 (0.76, 4.49) mSv in the head, 4.12 (1.90, 53.21) mSv in the chest, 5.96 (2.68, 10.25) mSv in the abdomen, and 10.30 (4.12, 12.67) mSv in the lumbar spine. By the end of 2020, the effective dose to the public in Shantou City was 6080.67 Sv·person, and the average annual effective dose per person was 1.10 mSv. Conclusion Medical exposure is the most important factor affecting resident dose burden, particularly the overuse of medical exposure examinations. CT examination is the most significant component of medical exposure causing resident dose burden. Reducing unnecessary medical exposure, ensuring the rational use of CT examination, and properly utilizing personal protective equipment are effective measures to minimize the dose burden on examinees.