Radiation dose in CT colonography--trends in time and differences between daily practice and screening protocols

Area of Science:

• Radiology
• Medical Imaging
• Radiation Dosimetry

Background:

• CT colonography (CTC) is a widely used imaging technique.
• Effective radiation doses in CTC are a significant consideration for patient safety and regulatory compliance.

Purpose of the Study:

• To assess current effective radiation doses in CT colonography (CTC).
• To identify temporal trends in CTC effective doses.
• To compare doses between screening and daily practice protocols.

Main Methods:

• Conducted a literature and congress abstract search for CTC studies.
• Administered a dose questionnaire to research institutions regarding CT parameters.
• Calculated effective doses using the ImPACT CT Dosimetry Spreadsheet.

Main Results:

• Median effective dose was 5.7 mSv for screening and 9.1 mSv for daily practice CTC protocols (p<0.05).
• No significant dose difference was observed between CT scanners with varying detector rows.
• Despite increased use of dose modulation, median effective dose for daily practice protocols decreased slightly from 11 mSv in 2004 to 9.7 mSv currently, a non-significant change.

Conclusions:

• Median effective dose for CTC is significantly lower in screening protocols compared to daily practice.
• Increased adoption of dose modulation techniques has not yet led to a significant reduction in overall CTC effective doses.
• Further research and optimization of CT parameters are needed to reduce radiation exposure in CTC.