U.S. Diagnostic Reference Levels and Achievable Doses for 10 Adult CT Examinations.

Area of Science:

• Radiology
• Medical Physics
• Health Informatics

Background:

• Computed tomography (CT) examinations are prevalent in adult diagnostics.
• Establishing radiation dose benchmarks is crucial for patient safety and quality assurance.
• Variability in patient size can influence radiation dose received during CT scans.

Purpose of the Study:

• To determine diagnostic reference levels (DRLs) and achievable doses (ADs) for the 10 most frequent adult CT examinations in the United States.
• To analyze these dose metrics as a function of patient size.
• To utilize data from the CT Dose Index Registry for comprehensive analysis.

Main Methods:

• Analysis of 1,310,727 adult CT examinations from 583 US facilities.
• Categorization of examinations into head, neck, and body scans.
• Use of lateral thickness for head scans and water-equivalent diameter for neck/body scans to assess patient size.
• Calculation of median, mean, and 25th/75th percentiles for CTDIvol, DLP, and SSDE.

Main Results:

• Abdomen and pelvis CT scans were the most common examination (45%).
• For body CT scans, DRLs and ADs (CTDIvol, SSDE, DLP) increased with patient size (water-equivalent diameter).
• The correlation between patient size and dose metrics was less pronounced for head and neck CT scans.

Conclusions:

• DRLs and ADs were successfully developed for 10 common adult CT examinations in the US, stratified by patient size.
• The findings provide valuable benchmarks for optimizing radiation dose in CT imaging.
• Results align with international DRL data, supporting global consistency in CT radiation management.