Determining Diagnostic Reference Levels (DRLs) for Radiography and Fluorsocopy Procedures in a University Based Teaching Hospital

Abstract

The introduction of the latest basic safety standard (BSS) into Irish legislation in 2018 will aid optimisation, justification and correction of high or low levels of radiation delivery as part of diagnostic procedures. Establishment and implementation of Local Diagnostic Reference Levels (LDRLs) play an important role in this optimisation process within Radiology Departments. This research focused on a review of LDRLs for both radiography and fluoroscopy procedures in a University based teaching hospital. LDRLs were based on the most commonly performed procedures in each room for adult patients (⩾18 years). As a retrospective dose audit, data acquisition was both manual, using the DICOM header information of individual images, and automatic using, Siemens CareAnalytics software. Dose-area product (DAP) data was acquired from fitted DAP meters used in five radiology rooms, encompassing 1,517 patient images, for 18 patients procedures over a three year period. Data analysis used SPSS statistical software on exposure parameters and patient characteristics for the DAP distributions of each procedure. LDRLs were then evaluated and compared with National and European DRLs for dose levels delivered. The key findings showed that LDRLs were lower than National published DRLs in both Ireland and the UK for each room. In addition, a good correlation was found between the LDRLs in rooms where the same procedures were conducted, using the same equipment. The findings suggest that a good level of X-ray examination protocol optimisation is ongoing within the Radiology Dept. A summary of the methodology used and the salient findings will be explored.