title: Detection of ground-glass opacities by use of hybrid iterative reconstruction (iDose) and low-dose 256-section computed tomography: a phantom study.
abstract: The detection of ground-glass opacities (GGOs) is an important issue in lung cancer screening with low-dose CT. The iterative reconstruction (IR) technique has the ability to improve the image quality relative to the filtered back projection (FBP) technique with low-dose CT. Our purpose was to investigate the ability to detect GGO in a chest phantom using a low-dose CT and hybrid IR, named iDose. Simulated GGOs in a chest phantom were scanned with 256-section CT at tube current second products of 20, 50, 100, and 200 mAs. Five radiologists visually assessed the detectability of GGOs in the phantom. The contrast-to-noise ratio (CNR) for GGOs was used as an estimate of image quality. Comparison of the detectability and CNR between standard images with 200 mAs-FBP and low-dose images with 20, 50, and 100-mAs FBP/iDose were performed by ANOVA with Dunnett's and Tukey's test. The detectability was significantly lower at 20-mAs FBP/iDose and 50-mAs FBP than that at 200-mAs FBP (p < 0.05). There was no significant difference between 50-mAs iDose and 200-mAs FBP and between 100-mAs iDose/FBP and 200-mAs FBP. The CNR was significantly higher on iDose images than that on FBP images at each mAs value. The CNR at 200-mAs FBP was the same as that at 50-mAs iDose (CNR:1.8). The hybrid IR technique and low-dose CT imaging with 50 mAs enabled noise and to maintain the detectability for GGOs in a chest phantom that is equivalent to the reference acquisitions of 200 mAs with FBP.
authors: Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku, Fukuoka-city, Fukuoka 812-8582, Japan. khiguchi@radiol.med.kyushu-u.ac.jp
authors: Ko
authors: K
authors: Higuchi
authors: Michinobu
authors: M
authors: Nagao
authors: Yoshio
authors: Y
authors: Matsuo
authors: Shunya
authors: S
authors: Sunami
authors: Takeshi
authors: T
authors: Kamitani
authors: Mikako
authors: M
authors: Jinnouchi
authors: Masato
authors: M
authors: Yonezawa
authors: Yuzo
authors: Y
authors: Yamasaki
authors: Hidetake
authors: H
authors: Yabuuchi
authors: Masamitsu
authors: M
authors: Hatkenaka
authors: Hiroshi
authors: H
authors: Honda
mesh_terms: D000465:Algorithms; D005898:Glass / Q000737:chemistry*; D006801:Humans; D019047:Phantoms, Imaging; D011857:Radiographic Image Interpretation, Computer-Assisted; D013902:Radiography, Thoracic / Q000295:instrumentation / Q000379:methods*; D003074:Solitary Pulmonary Nodule / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed
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