Investigation of radiation dose in CT scanning for adult patients in Ningxia / 中华放射医学与防护杂志

ABSTRACT

Objective To investigate the current status of CT radiation dose to adults in Ningxia, and provide basic data for developing the first diagnostic reference level of adults from CT scanning. Methods Stratified cluster sampling method was used to investigate the in-service status of CT scanners with various brands and different models in different grades of hospital in Ningxia. Interval sampling method was used to obtain everyday' s scanning parameters and radiation dose values from different types of scanning examinations in surveyed hostipitals. Basic information was collected include hospitals, CT scanner, scanning types and patients. CT scanning parameters, CTDIvol and DLP values were recorded, with effective dose values calculated. The data were statistically analyzed by examination types and comparation was made with the DRL values recommended by other countries. Results Finally, there were 45 medical institutions in this study, including 10 public tertiary A hospitals, 5 public tertiary B hospitals, 23 public secondary A hospitals, 5 private hospitals and 2 physical examination centers. 58 CT scanners from 6 manufacturers and 4952 adult patients were investigated. The 75th percentile (P75) of CTDIvol, DLP, and E values of common scanning examinations were listed as follows 65.67 mGy, 860.74 mGy·cm, and 1.64 mSv in skull scanning;29.32 mGy, 490. 00 mGy·cm, and 2.83 mSv in neck scanning;36. 92 mGy, 954. 42 mGy·cm, and 4. 87 mSv in neck enhanced scanning; 11. 50 mGy, 382.06 mGy·cm , and 5.68 mSv in chest scanning; 45.80 mGy, 1713.22 mGy·cm, and 25.01 mSv in chest enhanced scanning; 20. 10 mGy, 506. 59 mGy·cm, and 7. 75 mSv in upper abdominal scanning;50. 07 mGy, 1434. 19 mGy·cm, and 21. 94 mSv in upper abdominal enhanced scanning; 14. 33 mGy, 670.78 mGy·cm, and 10. 26 mSv in abdominal-pelvic scanning; 48. 00 mGy, 2294. 00 mGy·cm, and 35.10 mSv in abdominal-pelvic enhanced scanning;16.10 mGy, 471.58 mGy·cm, and 6.08 mSv in pelvic scanning;31.04 mGy, 1138. 78 mGy·cm, and 14. 69 mSv in pelvic enhanced scanning. Conclusions The CT scanning radiation doses to skull, neck, chest and pelvis in Ningxia are slightly lower than, or similar to, in other countries, but the abdominal scanning dose is significantly higher than that in other countries. It is necessary to optimize the abdominal CT scanning protocol.