Image quality comparison of a nonlinear image-based noise reduction technique with a hybrid-type iterative reconstruction for pediatric computed tomography. (August 2020)

• Record Type: Journal Article
• Authors: Watanabe, Shota; Ichikawa, Katsuhiro; Kawashima, Hiroki; Kono, Yuki; Kosaka, Hiroyuki; Yamada, Koji; Ishii, Kazunari
• Is Part Of: Physica medica. Volume 76(2020)
• Page Start: 100
• Page End: 108
• Publication Date: 2020-08
• Subjects: Computed tomography -- Iterative reconstruction -- Image quality assessment -- Pediatric abdominal imaging; Medical physics -- Periodicals; Biophysics -- Periodicals; Biophysics -- Periodicals; Imagerie médicale -- Périodiques; Radiothérapie -- Périodiques; Rayons X -- Sécurité -- Mesures -- Périodiques; Physique -- Périodiques; Médecine -- Périodiques; 610.153
• DOI: 10.1016/j.ejmp.2020.06.015
• Languages: English
• ISSNs: 1120-1797

Abstract

Highlights: CT image quality of an image-based noise reduction technique (iNoir) was assessed. We targeted scan and phantom conditions corresponding to pediatric abdominal CT. iNoir presented better image qualities compared with a hybrid IR. In contrast to hybrid-type IR, the noise texture change of iNoir was negligible. Abstract: Purpose: To compare computed tomography (CT) image properties between a vendor-independent image-based noise reduction technique, Image-space Noise Reduction (iNoir) and a hybrid-type iterative reconstruction technique, Adaptive Statistical Iterative Reconstruction (ASIR). Methods: A cylindrical water phantom, corresponding to pediatric body size, containing soft-tissue-equivalent rod and 12-mg iodine/ml rod was scanned at size-specific dose estimates of 8.4 and 16.7 mGy. For assessments of image quality and noise texture change, task-based system performance function (SPF) and peak frequency difference (PFD) were compared, respectively, among filtered back projection (FBP), IR image with 50%-blending rate (50%ASIR), 100%ASIR, 50%iNoir, and 100%iNoir. Human observer test for pediatric CT images was performed by radiologists. Results: For the soft-tissue contrast, SPF 2 of 100%iNoir was the highest. The average SPF 2 between 0.1 and 0.5 cycles/mm for 100%iNoir increased by approximately 70% compared with FBP, while ASIR indicted slight increases in the frequency region of >0.2 cycles/mm. For the iodine contrast, 100%iNoir indicated highest values at the spatial frequencies corresponding pediatric artery diameters. The PFDs of iNoir were negligible and lower than that of ASIR. The results of human observer test supported results of SPF 2 and PFD. Conclusions: Compared with ASIR, iNoir provided better image quality for pediatric abdominal CT without compromising noise texture change.