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DIAGNOSTIC REFERENCE LEVELS FOR CARDIAC CT ANGIOGRAPHY IN AUSTRALIA
Ali B Alhailiy1,2, Ernest U Ekpo1, Elaine A Ryan1
1Discipline of Medical Radiation Sciences, Faculty of Health Sciences, The University of Sydney, Lidcombe, New South Wales, Australia.
Radiation Protection Dosimetry
|July 23, 2018
Summary
Australian diagnostic reference levels (DRLs) for cardiac CT angiography (CCTA) were established for the first time. These recommended DRLs are lower than international benchmarks due to advanced dose-saving technologies.
Area of Science:
- Radiology
- Medical Imaging
- Radiation Dose Management
Background:
- Cardiac computed tomography angiography (CCTA) involves patient radiation exposure.
- Establishing national diagnostic reference levels (NDRLs) is crucial for radiation dose optimization in medical imaging procedures.
- Previous studies have not proposed specific NDRLs for CCTA in Australia.
Purpose of the Study:
- To assess patient radiation dose from CCTA procedures in Australia.
- To propose the first national diagnostic reference levels (NDRLs) for CCTA in Australia.
- To compare Australian CCTA dose levels with international data.
Main Methods:
- A retrospective questionnaire survey collected CCTA scanning and patient parameters from Australian CT centers.
- Data from 338 patients across nine CT centers were analyzed.
- The 75th percentile of volumetric CT dose index (CTDIvol) and dose length-product (DLP) were used to determine DRL values.
Main Results:
- The recommended CCTA DRLs for CTDIvol and DLP in Australia are 22 mGy and 268 mGy cm, respectively.
- A DRL for CT calcium scoring was determined as 137 mGy cm (DLP).
- Australian CCTA DRLs are lower than many international published values, attributed to dose-saving technologies.
Conclusions:
- National diagnostic reference levels (NDRLs) for CCTA have been recommended for Australia.
- The lower DRLs suggest successful implementation of dose reduction strategies like prospective ECG-gating and iterative reconstruction.
- Significant variations in patient doses between facilities highlight the need for DRLs to drive dose optimization efforts in Australian CT centers.
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