Establishing Protocol-based Dose Metrics for Common Abdomen and Pelvis Computed Tomography Protocols

Area of Science:

• Medical Imaging
• Radiology
• Radiation Protection

Background:

• Current diagnostic reference levels (DRLs) for computed tomography (CT) are often based on anatomical regions.
• DRLs aim to improve radiation protection by comparing similar examinations.
• There is a need to explore alternative methods for establishing dose baselines.

Purpose of the Study:

• To investigate the feasibility of establishing radiation dose baselines for enhanced CT abdomen and pelvis examinations.
• To compare dose metrics across different CT protocols used for these exams.

Main Methods:

• Retrospective analysis of dose metrics (tDLPs, CTDIvol, SSDE, E) from 216 adult patients undergoing enhanced CT abdomen and pelvis exams.
• Statistical analysis using Spearman coefficient and one-way ANOVA to compare dose metrics across CT protocols.

Main Results:

• Nine different CT protocols were identified, with four being most common.
• Significant differences (p < 0.0001) were observed in dose metrics between anatomical locations and CT protocols.
• Triphasic liver protocol showed the highest mean and median total dose length product (tDLPs) and effective dose (E).

Conclusions:

• Existing anatomical-based DRLs show wide variability in CT dose indices and patient dose metrics.
• Establishing dose baselines based on specific CT protocols is essential for optimizing patient radiation dose.