title: Lung cancer screening with ultra-low dose CT using full iterative reconstruction.
abstract: OBJECTIVE
  To investigate the diagnostic capability of ultra-low-dose CT (ULDCT) with full iterative reconstruction (f-IR) for lung cancer screening.
  
  
  METHODS
  All underwent ULDCT and/or low-dose CT (LD-CT) on a 320-detector scanner. ULDCT images were reconstructed with f-IR. We qualitatively and quantitatively studied 95 nodules in 69 subjects. Two radiologists classified the nodules on ULDCT images as solid-, part-solid-, and pure ground-glass (PGG) and recorded their mean size. Their findings were compared with the reference standard. The observer performance study included 7 other radiologists and 35 subjects with- and 15 without nodules. The results were analyzed by AFROC analysis.
  
  
  RESULTS
  In the qualitative study, the kappa values between observers 1 and 2, respectively, and the reference standard were 0.70 and 0.83; the intra-class correlation coefficients for the nodule diameter between the reference standard and their measurements were 0.84 and 0.90. The 95% confidence interval (CI) for the area under the curve (AUC) difference for nodule detection on LDCT and ULDCT was -0.03 to 0.07. The 95% CI crossed the 0 difference in the AUC but not the pre-defined non-inferiority margin of -0.08.
  
  
  CONCLUSIONS
  The diagnostic ability of ULDCT using f-IR is comparable to LDCT.
authors.affiliation: Department of Diagnostic Radiology, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima, Hiroshima, 734-8551, Japan.
authors.forename: Masayo
authors.initials: M
authors.lastname: Fujita
authors.affiliation: Department of Diagnostic Radiology, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima, Hiroshima, 734-8551, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Higaki
authors.affiliation: Department of Internal Medicine, Miyoshi Central Hospital, 531 Sakaya-cho, Miyoshi, Hiroshima, 728-0023, Japan.
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Awaya
authors.affiliation: Department of Internal Medicine, Miyoshi Central Hospital, 531 Sakaya-cho, Miyoshi, Hiroshima, 728-0023, Japan.
authors.forename: Toshio
authors.initials: T
authors.lastname: Nakanishi
authors.affiliation: Department of Diagnostic Radiology, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima, Hiroshima, 734-8551, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Nakamura
authors.affiliation: Department of Diagnostic Radiology, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima, Hiroshima, 734-8551, Japan.
authors.forename: Fuminari
authors.initials: F
authors.lastname: Tatsugami
authors.affiliation: Department of Diagnostic Radiology, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima, Hiroshima, 734-8551, Japan.
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Baba
authors.affiliation: Department of Diagnostic Radiology, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima, Hiroshima, 734-8551, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Iida
authors.affiliation: Department of Diagnostic Radiology, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima, Hiroshima, 734-8551, Japan. awai@hiroshima-u.ac.jp.
authors.forename: Kazuo
authors.identifier: http://orcid.org/0000-0002-5039-2546
authors.initials: K
authors.lastname: Awai
mesh_terms: D000368:Aged; D055088:Early Detection of Cancer / Q000379:methods; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods
keywords: Low-dose CT; Lung cancer CT screening; Ultra-low-dose CT