Radiation Doses of Various CT Protocols: a Multicenter Longitudinal Observation Study

Area of Science:

• Radiology
• Medical Physics
• Public Health

Background:

• Growing concerns exist regarding potential hazards from medical radiation, particularly from computed tomography (CT) examinations.
• Effective radiation dose management is crucial for patient safety in diagnostic imaging.

Purpose of the Study:

• To longitudinally track changes in CT radiation doses across diverse CT protocols.
• To evaluate the impact of supervising radiologists' efforts in reducing medical radiation exposure over time.

Main Methods:

• Collected radiation dose data, including volume CT dose index (CTDIvol) and dose length product (DLP), from 11 CT protocols across 12 hospitals.
• Data were gathered at two time points: 2007 and 2010, noting CT machine types.
• Calculated total DLP and effective dose (ED) for comparison between the two time points, stratified by protocol, machine type, and hospital.

Main Results:

• A significant decrease in CTDIvol was observed, with the exception of dynamic liver CT protocols.
• Total DLP and effective dose (ED) showed significant reductions across all 11 protocols.
• Radiation dose reduction was more pronounced with newer CT scanner models, though substantial hospital-specific variability in ED changes was noted.

Conclusions:

• CT radiation doses demonstrably decreased between 2007 and 2010, reflecting successful dose reduction initiatives.
• Efforts by radiologists and the broader medical society have positively impacted medical radiation exposure from CT procedures.
• Continued monitoring and standardized practices are essential to manage variability and further optimize radiation safety.