Application of European Commission reference dose levels in CT examinations in Crete, Greece

The purpose of this study was to apply European Commission reference dose l evels (EC RDLs) to routine CT examinations. The dosimetric quantities propo sed in the European Guidelines (EG) for CT are weighted computed tomography dose index (CTDIw) for a single slice and dose-length product (DLP) for a complete examination. Patient-related data as well as technical parameters for brain, chest, abdomen and pelvis examinations were collected for four C T scanners in the Euromedica Medical Center. Computed tomography dose index (CTDI) measurements were performed on each scanner and CTDIw, DLP and effe ctive dose E were estimated for each type of examination for a random sampl e of 10 typical patients. Mean values of CTDIw had a range of 27.0-52.0 mGy for brain and 13.9-26.9 mGy for chest, abdomen and pelvis examinations. Me an values of DLP had a range of 430-758 mGy em for brain, 348-807 mGy cm fo r chest, 278-582 mGy cm for abdomen and 306-592 mGy cm for pelvis examinati ons. Mean values of E were 1.4 mSv for brain, 10.9 mSv for chest, 7.1 mSv f or abdomen and 9.3 mSv for pelvis examinations. Results confirm that the Eu romedica Medical Center meets EC RDLs for brain, abdomen and pelvis examina tions, in terms of radiation dose and examination technique. As far as ches t examination is concerned, although CTDIw of each scanner is within propos ed values, the DLP is consistently exceeded, probably because of the large irradiation volume length L. It is anticipated that a reduction of L, or pr oduct mAs, or their combination, will reduce DLP without affecting image qu ality.