Continuous monitoring of CT dose indexes at Dubai Hospital.

OBJECTIVE: Experience of continuous monitoring and control of patient doses in CT in Dubai Hospital over a period of approximately 4 years (January 2008 through August 2011) is presented. MATERIALS AND METHODS: Dose measurements-in particular, weighted and volumetric CT dose index, dose-length product (DLP), and estimated effective dose-were regularly monitored using head (16 cm diameter) and body (32 cm diameter) CT phantoms. Patient radiation dose indexes were manually recorded during 2008 for common CT examinations: head, chest, and abdomen and pelvis scans. In 2009-2011, these CT dose data were recorded within the radiology information system and the PACS. Dose reduction actions were taken while maintaining a watch on image quality. The effects of these factors were monitored through change in average DLP on a monthly basis and third quartile annually. Adapted diagnostic reference levels were used for comparison. RESULTS: The reduction in adult dose indexes in 2010 as compared with 2008 was 52%, 16.4%, and 34.8% for head, chest, and abdomen and pelvis examinations, respectively. For the pediatric group, the reduction was 45.23%, 39.6%, and 43.34% for head, chest, and abdomen and pelvis examinations, respectively. CONCLUSION: Substantial reduction in DLP for common examinations of adults and children is shown through a program of continuous monitoring and action. The results indicate the need to introduce local diagnostic reference levels to substitute for the adapted ones.

Patient doses in radiographic examinations in 12 countries in Asia, Africa, and Eastern Europe: initial results from IAEA projects.

OBJECTIVE: The purpose of this study was to survey image quality and the entrance surface air kerma for patients in radiographic examinations and to perform comparisons with diagnostic reference levels. SUBJECTS AND METHODS: In this multinational prospective study, image quality and patient radiation doses were surveyed in 12 countries in Africa, Asia, and Eastern Europe, covering 45 hospitals. The rate of unsatisfactory images and image quality grade were noted, and causes for poor image quality were investigated. The entrance surface doses for adult patients were determined in terms of the entrance surface air kerma on the basis of X-ray tube output measurements and X-ray exposure parameters. Comparison of dose levels with diagnostic reference levels was performed. RESULTS: The fraction of images rated as poor was as high as 53%. The image quality improved up to 16 percentage points in Africa, 13 in Asia, and 22 in Eastern Europe after implementation of a quality control (QC) program. Patient doses varied by a factor of up to 88, although the majority of doses were below diagnostic reference levels. The mean entrance surface air kerma values in mGy were 0.33 (chest, posteroanterior), 4.07 (lumbar spine, anteroposterior), 8.53 (lumbar spine, lateral), 3.64 (abdomen, anteroposterior), 3.68 (pelvis, anteroposterior), and 2.41 (skull, anteroposterior). Patient doses were found to be similar to doses in developed countries and patient dose reductions ranging from 1.4% to 85% were achieved. CONCLUSION: Poor image quality constitutes a major source of unnecessary radiation to patients in developing countries. Comparison with other surveys indicates that patient dose levels in these countries are not higher than those in developed countries.