Abstract
BackgroundThe arms-down position increases computed tomography (CT) radiation dose. Iterative reconstruction (IR) could enhance image quality without increasing radiation dose in patients with arms-down position.AimTo investigate the feasibility of reduced-dose CT with IR for patients with inappropriate arm positioningMethodsTwenty patients who underwent two-phase abdominopelvic CT including standard-dose and reduced-dose CT (performed with 80% of the radiation dose of the standard protocol) with their arms positioned in the abdominal area were included in this study. Reduced-dose CT images were reconstructed using filtered back projection (FBP), hybrid IR, and iterative model reconstruction (IMR). These images were compared with standard-dose CT images reconstructed with FBP. Objective image noise in the liver and subcutaneous fat was measured by standard deviation for the quantitative analysis. Then, two radiologists qualitatively assessed beam hardening artifacts, artificial texture, noise, sharpness, and overall image quality in consensus.ResultsReduced-dose CT with all IR levels had lower objective image noise compared to standard-dose CT with FBP reconstruction (P < 0.05). Quantitatively measured beam hardening artifacts were similar in reduced-dose CT with iDose levels 5–6 and fewer with IMR compared to standard-dose CT. In the qualitative analysis, beam hardening artifacts and noise decreased as the IR levels increased. However, artificial texture was significantly aggravated with iDose 5–6 and IMR, and overall image quality significantly worsened with IMR.ConclusionsIR algorithms can reduce beam hardening artifacts in a reduced-dose CT setting in patients with arms-down position, and an intermediate level of hybrid IR allows radiologists to obtain the best image quality. Because the retrospective and single-center nature of our study limited the number of patients, multicenter prospective clinical studies are required to validate our results.
Highlights
Measured beam hardening artifacts were similar in reduced-dose computed tomography (CT) with iDose levels 5–6 and fewer with iterative model reconstruction (IMR) compared to standard-dose CT
Iterative reconstruction (IR) algorithms can reduce beam hardening artifacts in a reduced-dose CT setting in patients with arms-down position, and an intermediate level of hybrid IR allows radiologists to obtain the best image quality
Abdominopelvic computed tomography (CT) is usually performed with arms positioned above shoulders because beam hardening artifacts and quantum mottle/photon starvation caused by arms in the scan range negatively affect image quality and increase radiation exposure
Summary
Abdominopelvic computed tomography (CT) is usually performed with arms positioned above shoulders because beam hardening artifacts and quantum mottle/photon starvation caused by arms in the scan range negatively affect image quality and increase radiation exposure. Several alternatives have been suggested to attain the best image quality in traumatized patients with incorrect arm positioning [5,6]. These methods have focused on modifying the arm position. In patients who cannot elevate both arms, better image quality can be achieved by raising at least one arm [5]. Iterative reconstruction (IR) could enhance image quality without increasing radiation dose in patients with arms-down position
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
