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

OBJECTIVE
To assess the influence and significance of the use of iterative reconstruction (IR) algorithms on patient dose in CT in Australia.


METHODS
We examined survey data submitted to the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) National Diagnostic Reference Level Service (NDRLS) during 2013 and 2014. We compared median survey dose metrics with categorization by scan region and use of IR.


RESULTS
The use of IR results in a reduction in volume CT dose index of between 17% and 44% and a reduction in dose-length product of between 14% and 34% depending on the specific scan region. The reduction was highly significant (p < 0.001, Wilcoxon rank-sum test) for all six scan regions included in the NDRLS. Overall, 69% (806/1167) of surveys included in the analysis used IR.


CONCLUSION
The use of IR in CT is achieving dose savings of 20-30% in routine practice in Australia. IR appears to be widely used by participants in the ARPANSA NDRLS with approximately 70% of surveys submitted employing this technique.


ADVANCES IN KNOWLEDGE
This study examines the impact of the use of IR on patient dose in CT on a national scale.