title: Standard-dose vs. low-dose CT protocols in the evaluation of localized lung lesions: Capability for lesion characterization-iLEAD study.
abstract: OBJECTIVE
  To determine the lesion characterization capability by low dose CT for localized lung lesions in comparison with standard dose CT.
  
  
  METHODS
  Approval for this study was granted by our Institutional Review Board. Fifty-two consecutive patients (36 males and 16 females, median age of 71 years.) who had CT examinations for evaluation of lung lesions comprise the study population. Two chest CT scans were performed with current time product of 50 and 150 mAs at 120 kVp, with the same scan length with a 16 detector-row CT scanner. Three readers evaluated 52 target lesions and assigned an overall impression score to each target lesion, using a 5 point scale from 1 (definitely benign) to 5 (definitely malignant). Six features of the lesions including lesion type, margin characteristics, calcification, lobulation, speculation, and pleural indentation were also reported with 5-point scales. The weighted kappa analyses and receiver operating characteristic analysis were used for analysis.
  
  
  RESULTS
  The mean kappa value between low-and standard-dose CT was 0.82 for overall impression of the lesions, showing almost perfect agreement. Area under the curve of low-dose CT (Az = 0.74) had no significant difference from that of standard-dose CT (Az = 0.74) (p = 0.61). The kappa values for six lesion features ranged from 0.45 to 0.83, showing moderate to almost perfect agreement.
  
  
  CONCLUSIONS
  Lesion characterization capability by low-dose CT images was comparable to that by standard-dose CT images and therefore sufficient for evaluation of localized lung lesions.
authors.affiliation: Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kubo
authors.affiliation: Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan.
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Ohno
authors.affiliation: Department of Radiology, Hyogo Cancer Center, 13-70 Kitaouji-cho, Akashi, 673-8558, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Takenaka
authors.affiliation: Department of Radiology, Dana Farber Cancer Institute, 44 Binney Street, Boston, MA 02115, United States.
authors.forename: Mizuki
authors.initials: M
authors.lastname: Nishino
authors.affiliation: Departments of Radiology, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Boston, MA 02215, United States.
authors.forename: Shiva
authors.initials: S
authors.lastname: Gautam
authors.affiliation: Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan.
authors.forename: Kazuro
authors.initials: K
authors.lastname: Sugimura
authors.affiliation: Diagnostic and Interventional Radiology, University Clinic Heidelberg, Im Neuenheimer Feld 110, D-69120 Heidelberg, Germany.
authors.forename: Hans Ulrich
authors.initials: HU
authors.lastname: Kauczor
authors.affiliation: Department of Radiology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115, United States.
authors.forename: Hiroto
authors.initials: H
authors.lastname: Hatabu
keywords: Chest CT; Lung masses; Lung nodules; Radiation dose reduction