Research on the application frequency and its distribution of medical diagnostic X-ray computed tomography in Shanghai

The continuously increasing and wide spread use of X-ray CT has become a hot spot in the field of medical radiation protection that requires special attention. Therefore, in a research program on medical exposure levels conducted during the Eleventh Five X-ray computed tomography (X-CT); medical exposure; application frequency; distribution Shanghai Year Plan period in Shanghai, emphases were laid upon surveys to including the basic information, application frequency of and dose level caused by the medical diagnostic X-CT scanners in Shanhai. This article analyzes the basic information on X-CT scanners and their application frequencies in Shanghai, and compares with the world status as well. At the end of 2009, a total of 152 sets of X-CT scanners were in use in 112 hospitals throughout the city, which means the number of CT scanners per million population was averaged up to be more than 7.9 for the whole municipality, and 16.9 for the population in the central areas. The annual number of medical X-CT examinations has increased to 137.84 per thousand population, which accounted for 17.7% of the total number of medical X-ray diagnosis in Shanghai in 2009, and the number was 4.2 times of that in 1996. Further analyses revealed that the main types of examinations concentrated in the head, chest and abdomen scans, the frequency for males was higher than that for females, and the examinees were mostly older than 40. From the four-point revelations finally discussed, there is really an urgent need to strengthen the radiological protection in X-ray CT examinations, and it is a prominent and important issue in the field of medical radiation protection. (authors)