Work

Impact of various iterative reconstruction algorithms on the noise power spectrum in low-dose CT imaging

Year: 2025

Type: article

Abstract: Introduction The utilization of a low dose computed tomography (LDCT) protocol can pose potential drawbacks in image quality by increasing image noise. The purpose of this study was to assess the efficacy of iterative reconstruction (IR) for noise reduction by evaluating the noise power spectrum (NPS) reduction in LDCT CT brain imaging using a phantom study. Methods This study involved scanning the uniform water section of the scanner phantom under different CT dose protocols. Reconstructions were performed using various slice thicknesses and vendor-specific IR algorithms. Three CT scanners of different vendors: Siemens, Philips, and GE were used. Two dose protocols for brain CT were used, the LDCT protocol with volume computed tomography dose index (CTDI vol ) of 35 mGy, and the standard protocol (CTDI vol of 65 mGy). The images were reconstructed using various IR algorithms such as Philips intelligence dose Level 4 (iDose 4 ) algorithm, Siemens sinogram affirmed iterative reconstruction (SAFIRE) Level 4 (S4) algorithm, and GE adaptive statistical iterative reconstruction (ASiR-V) algorithm and compared with filtered back projection (FBP). IndoQCT software was used to automatically calculate the NPS and noise level. Results The results show that the higher dose protocol and thicker slice acquisition reduce the noise level. Various IR algorithms reduced image noise and shifted the NPS curve down in comparison with filtered-back projection. The percentage of noise reduction in the LDCT protocol, compared to the reference image, was 12.82 %, 27.75 %, and 46.62 % for SAFIRE, iDose 4 , and ASiR-V, respectively, for 2 mm/2.5 mm slice thickness. For 5 mm slice thickness, the percentages of noise reduction were 10.95 %, 24.47 %, and 48.75 % for SAFIRE, iDose 4 , and ASiR-V, respectively. Conclusions It can be concluded that IR algorithms proved to be effective in reducing noise in LDCT CT protocols, thereby enabling the generation of images with comparable quality to those obtained through standard dose (SDCT) protocols.

Source: Radiation Physics and Chemistry

DOI: 10.1016/j.radphyschem.2025.113455

Authors: Hamza Arjah, Hussein ALMasri, Choirul Anam, Mohd Ezane Aziz, Noor Diyana Osman

Institutions: Universiti Sains Malaysia, Al-Quds University, Diponegoro University, Hospital Universiti Sains Malaysia

Language: English

Topic: Radiation Dose and Imaging

Subfield: Radiology, Nuclear Medicine and Imaging

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: hybrid

Estimated APC paid: $3,530