Patient Dose Estimation on Multi Detector-row CT from Abdomen for Adult and Abdomen-pelvis for Child Examinations

抄録

Many multi detector-row CT scanners a re used clinically in Japan. Care must be taken because of the higher exposure of MDCT than single-slice CT due to the narrow slice separation of the former.
Various organ or tissue doses in the abdomen examination for an adult and abdomen-pelvis examination for a child were measured using anthropometric phantoms and TLDs, and their effective doses were evaluated according to ICRP60. For the adult abdomen scan, doses of organs located in the abdomen were around 20-30 mGy. The effective doses ranged from 7-13 mSv and averaged 8.4 mSv. The difference of effective doses between MDCT and single-slice CT was not substantial. For the child abdomen-pelvis scan, organ doses for organs located in the abdomen were around 10-20 mGy. The effective doses were 5-14 mSv. The child abdomen-pelvis scan doses varied greatly between facilities and devices.
It is necessary to search for the optim a l dose in relation to the image quality when using MDCT.