Effect of iterative reconstructions in low dose computed tomography

Objectives: To assess the patient radiation dose profiles in routine body image acquisitions when using iterative reconstruction (IR) methods and compare them with filtered back projection technique. Material and methods: Iterative dose profiles of 986 patients – Thorax (317), Abdomen/Pelvis (540), Thorax/Abdomen/Pelvis (129) in routine clinical practice have been evaluated and effective patient dose estimated from dose length product (DLP) Values. Within the evaluated samples, distribution of CT Dose Index (CTDI) and DLP values were calculated. Results: In Thorax, average DLP delivered was 286.30 mGy.cm which corresponded to an effective patient dose of 4.008 mSv. In Abdomen/Pelvis group, average value of DLP was 495.5 mGy, estimated dose was 7.43 mSv. In trunk study group average DLP was 570.21 mGy which corresponded to an effective dose of 8.55 mSv. Conclusion: Substantial dose reduction is achieved with iterative techniques. In 986 patients scans evaluated, average dose reduction of 33.2% in Thorax, 32.455% in Abdomen/Pelvis and 49.706% in trunk examinations were estimated.