Establishment of Local Diagnostic Reference Levels for Computed Tomography Procedures Using Dose Management Software: A Comparison with Manual Methods

Background: Medical imaging radiation dose records are important for the process of optimising patient imaging in radiography. Understanding and monitoring the ionizing radiation doses delivered to patients while carrying out an imaging protocol is essential if that imaging protocol is to be adjusted with the goal of achieving a clinically acceptable result while reducing the radiation dose delivered to patients. Dose management software (DMS) systems are now available for use in conjunction with picture archiving and communication systems (PACS). They facilitate the collection and analysis of Digital Imaging and COmmunications in Medicine (DICOM) standard radiation dose structured reports (RDSRs). Implementation of DMS systems allows for the routine establishment of local diagnostic reference levels (LDRLs) for defined clinical imaging protocols in medical imaging including for computed tomography (CT), fluoroscopic, and general radiographic modalities.Materials and Methods: Implementation of a DMS was recently completed in a Local Health District in New South Wales in conjunction with a PACS upgrade across the district. LDRLs obtained using this DMS have been assessed and compared to the manual methods used for compiling contributions to nationwide surveys carried out by the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) to establish national LDRLs for a range of CT imaging protocols.Results and Discussion: The mean difference between the dose metrics determined for LDRLs using manually generated and comprehensive DMS samples was 6.9% when using volumetric computed tomography dose index as dose metric, and 6% when using dose length product as the dose metric.Conclusion: Results of the comparison show that a DMS can readily replace manual surveys conducted previously, and RDSRs allow greater opportunity to better understand the factors impacting the doses delivered during CT procedures.