Evaluation of Radiation Exposure Reduction using Hybrid Iterative Reconstruction Algorithm in Chest-Abdomen-Pelvis CT

Abstract

Despite undeniable clinical benefits of Chest-Abdomen-Pelvis (CAP) Computed Tomography (CT), there is a raised concern about patient exposure that recommends optimization and reduction of the radiation exposure. Iterative Reconstruction (IR) methods are a promising tool in order to achieve dose reduction without degrading the diagnostic outcome. The aim of this study is to estimate the radiation exposure reduction using hybrid IR (iDose 4 ) technique compared to filtered back projection (FBP) in CAP CT scanning. CAP CT exams were performed in 164 patients with FBP and in 98 with iDose 4 Level 4 on a 64-slice multi-detector CT (Philips Brilliance 64). Patients were subdivided into three weight groups (Group 1: 41-60 kg, Group 2: 61-90 kg and Group 3: ³90 kg). Volume dose CT index (CTDIvol) and dose length product (DLP) were recorded, while effective dose was calculated from DLP measurements. All CT images were diagnostically acceptable. Compared with the standard FBP protocol there was an overall 48.5% decrease (statistically significant, p<0.001) in effective dose with iDose 4 technique. The radiation dose reduction in each of the weight groups were 54.4% (Group 1), 46.2% (Group 2) and 47.5% (Group 3). In our experience, iDose 4 allows a significant reduction in radiation exposure in CAP CT examinations.