Survey of computed tomography technique and radiation dose in Sudanese hospitals

The purpose of this study was to survey technique and radiation absorbed dose in CT examinations of adult in Sudan and to compare the results with the reference dose levels. Questionnaire forms were completed in nine hospitals and a sample of 445 CT examinations in patients. Information on patient, procedure, scanner, and technique for common CT examinations were collected. For each facility, the radiation absorbed dose was measured on CT dose phantom measuring 16 cm (head) and 32 cm (body) in diameter and was used to calculate the normalized CT air kerma index. Volume CT air kerma index (C_VOL), CT air kerma-length product (P_KL,CT) values were calculated using the measured normalized CT air kerma index and questionnaire information. The effective dose, E estimates was determined by using P_KL,CT measurements and appropriate normalized coefficients. Assuming the sample to offer a fair representative picture of CT practice patterns in Sudan, the mean C_VOL and P_KL,CT values were comparable or below the reference doses: 65 mGy and 758 mGy cm, respectively at head CT; 11.5 mGy and 327 mGy cm, respectively at chest CT; 11.6 mGy and 437 mGy cm, respectively at abdominal CT; and 11.0 mGy and 264 mGy cm, respectively at pelvis CT. Estimated effective doses were 1.6, 4.6, 6.6 and 4.0 mSv, respectively. The study offered a first national dose survey and provided a mean for quality control and optimization of CT practice within the country.