Australian diagnostic reference levels for multi detector computed tomography

Area of Science:

• Medical Physics
• Radiological Protection
• Public Health

Background:

• Diagnostic reference levels (DRLs) are crucial for optimizing radiation dose in medical imaging.
• Multi-detector computed tomography (MDCT) is a widely used diagnostic imaging modality.
• Establishing national DRLs ensures consistent and safe radiation practices across Australia.

Purpose of the Study:

• To establish the first set of national diagnostic reference levels (DRLs) for multi-detector computed tomography (MDCT) in Australia.
• To collect and analyze dosimetry data from Australian radiology clinics.
• To compare Australian radiation doses with European benchmarks.

Main Methods:

• Web-based surveys collected dose length product (DLP) and volume computed tomography dose index (CTDIvol) data for six common MDCT protocols.
• Practice reference levels (PRLs) were calculated as the median DLP/CTDIvol from compliant surveys (≥10 patients).
• Australian National DRLs were determined as the 75th percentile of PRLs for each protocol and age group.

Main Results:

• National DRLs for adult MDCT were established in terms of DLP for Head, Neck, Chest, AbdoPelvis, ChestAbdoPelvis, and Lumbar Spine protocols.
• Specific DLP DRLs: 1000, 600, 450, 700, 1200, and 900 mGy·cm, respectively.
• Australian MDCT doses were found to be higher than European averages for four out of six protocols.

Conclusions:

• Australian National DRLs for adult MDCT have been successfully determined.
• The survey highlights potential areas for dose optimization in Australian radiology practices.
• Ongoing data collection will allow for periodic updates to DRLs, reflecting technological advancements.