title: Impact of Reconstruction Algorithms on CT Radiomic Features of Pulmonary Tumors: Analysis of Intra- and Inter-Reader Variability and Inter-Reconstruction Algorithm Variability.
abstract: OBJECTIVE
  To identify the impact of reconstruction algorithms on CT radiomic features of pulmonary tumors and to reveal and compare the intra- and inter-reader and inter-reconstruction algorithm variability of each feature.
  
  
  METHODS
  Forty-two patients (M:F = 19:23; mean age, 60.43±10.56 years) with 42 pulmonary tumors (22.56±8.51mm) underwent contrast-enhanced CT scans, which were reconstructed with filtered back projection and commercial iterative reconstruction algorithm (level 3 and 5). Two readers independently segmented the whole tumor volume. Fifteen radiomic features were extracted and compared among reconstruction algorithms. Intra- and inter-reader variability and inter-reconstruction algorithm variability were calculated using coefficients of variation (CVs) and then compared.
  
  
  RESULTS
  Among the 15 features, 5 first-order tumor intensity features and 4 gray level co-occurrence matrix (GLCM)-based features showed significant differences (p<0.05) among reconstruction algorithms. As for the variability, effective diameter, sphericity, entropy, and GLCM entropy were the most robust features (CV≤5%). Inter-reader variability was larger than intra-reader or inter-reconstruction algorithm variability in 9 features. However, for entropy, homogeneity, and 4 GLCM-based features, inter-reconstruction algorithm variability was significantly greater than inter-reader variability (p<0.013).
  
  
  CONCLUSIONS
  Most of the radiomic features were significantly affected by the reconstruction algorithms. Inter-reconstruction algorithm variability was greater than inter-reader variability for entropy, homogeneity, and GLCM-based features.
authors.affiliation: Department of Radiology, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Hyungjin
authors.initials: H
authors.lastname: Kim
authors.affiliation: Department of Radiology, Seoul National University College of Medicine, Seoul, Korea.|Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Korea.|Cancer Research Institute, Seoul National University, Seoul, Korea.
authors.forename: Chang Min
authors.initials: CM
authors.lastname: Park
authors.affiliation: Department of Radiology, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Myunghee
authors.initials: M
authors.lastname: Lee
authors.affiliation: Department of Radiology, Seoul National University College of Medicine, Seoul, Korea.|Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Korea.|Cancer Research Institute, Seoul National University, Seoul, Korea.
authors.forename: Sang Joon
authors.initials: SJ
authors.lastname: Park
authors.affiliation: Department of Radiology, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Yong Sub
authors.initials: YS
authors.lastname: Song
authors.affiliation: Department of Radiology, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Jong Hyuk
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Radiology, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Eui Jin
authors.initials: EJ
authors.lastname: Hwang
authors.affiliation: Department of Radiology, Seoul National University College of Medicine, Seoul, Korea.|Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Korea.|Cancer Research Institute, Seoul National University, Seoul, Korea.
authors.forename: Jin Mo
authors.initials: JM
authors.lastname: Goo
mesh_terms: D000368:Aged; D000465:Algorithms; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed