Evidence of dose saving in routine CT practice using iterative reconstruction derived from a national diagnostic...

Area of Science:

• Medical Imaging Physics
• Radiological Protection
• Health Technology Assessment

Background:

• Iterative reconstruction (IR) algorithms represent a significant advancement in CT imaging technology.
• Assessing the real-world impact of IR on patient radiation dose is crucial for optimizing diagnostic imaging practices.
• Previous studies have indicated potential dose reduction with IR, but national-scale data is limited.

Purpose of the Study:

• To evaluate the influence and effectiveness of iterative reconstruction (IR) algorithms on patient radiation dose in computed tomography (CT) within Australia.
• To quantify the dose savings achieved by IR in routine clinical practice.
• To determine the prevalence of IR usage in Australian CT examinations.

Main Methods:

• Analysis of survey data from the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) National Diagnostic Reference Level Service (NDRLS) for 2013-2014.
• Comparison of median survey dose metrics (Volume CT Dose Index and Dose-Length Product) stratified by scan region and IR utilization.
• Statistical analysis, including the Wilcoxon rank-sum test, to assess the significance of observed dose reductions.

Main Results:

• The implementation of IR algorithms led to a notable reduction in patient dose, with Volume CT Dose Index decreasing by 17-44% and Dose-Length Product by 14-34%, varying by scan region.
• These dose reductions were statistically significant (p < 0.001) across all six investigated scan regions.
• Approximately 69% of the analyzed CT surveys utilized IR, indicating widespread adoption.

Conclusions:

• Iterative reconstruction (IR) is effectively reducing patient radiation doses in routine CT practice in Australia, with typical savings ranging from 20% to 30%.
• The widespread use of IR, evident in approximately 70% of submitted surveys, highlights its integration into Australian radiology departments.
• This national-scale study confirms the significant impact of IR on patient dose reduction in CT, advancing knowledge in radiological protection.