Reducing effective dose | Philips Healthcare

Reducing effective dose with iterative reconstruction techniques

This study intended to compare the dose delivered to patients and image quality in a clinical routine abdominal CT scan with no iterative reconstruction techniques (IR) relative to an examination conducted on a scanner with IR.

Case objectives
This is a retrospective study of 30 patients who underwent two abdominal examinations: one on a 64-slice scanner without IR and another one on a 256-slice scanner with IR. The patients, on medical follow-up for a chronic abdominal disease, had an exam on each scanner using the same protocol comprising an abdominopelvic time portal phase.

Mr Anthony Tessier

X-ray technician

Hospital Instruction of Armées Sainte-Anne

France

Clinical and patient background
The length of acquisition, the effective dose, and the dose length product (DLP) as well as quantitative and qualitative assessments of the image were compared.

Dose management methods and techniques that were used
The average effective dose per examination was 17 mSv with the 64-slice scanner (PDL: 1000 mGy.cm) compared to 11 mSv with the 256-slice scanner (PDL: 600 mGy.cm), hence a reduction of 36 %. The length of acquisition and quantification were comparable in both groups. The qualitative assessment was slightly higher on the 64-slice scanner but no examination was considered suboptimal.

Using a scanner equipped with IR
significantly reduces the effective dose while maintaining image quality.”

- Mr Anthony Tessier - X-ray technician

Hospital Instruction of Armées Sainte-Anne, France

Conclusions and results

Using a scanner equipped with IR significantly reduces the effective dose while maintaining image quality.

Discussion of case outcome(s) and future implications
The entire staff of the department has been informed of these first results and made aware of the optimization of delivered doses on the 64-slice scanner.

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