title: Diagnostic performance of CT, PET, side-by-side, and fused image interpretations for restaging of non-Hodgkin lymphoma.
abstract: OBJECTIVE
  The purpose of this study was to compare the diagnostic performance of positron emission tomography (PET) alone, computed tomography (CT) alone, side-by-side reading, and fused images for restaging or follow-up of patients with malignant lymphoma.
  
  
  METHODS
  Fifty patients with histologically confirmed non-Hodgkin lymphoma underwent an (18)fluoro-2-deoxyglucose (FDG)-PET scan, followed by a CT scan. CT alone, PET alone, side-by-side reading, and fused images were interpreted separately and visually using a five-point grading scale for the following eight regions: cervical, supraclavicular, axillary, mediastinal, para-aortic to iliac, mesenteric, inguinal, and extra-nodal. Diagnostic accuracy was compared on the basis of the final diagnoses determined by histological confirmation and/or clinical course.
  
  
  RESULTS
  For all regions combined, the interpretation of PET alone (sensitivity = 86.1%, specificity = 99.4%, accuracy = 91.0%), side-by-side reading (96.0%, 99.4%, 98.9%), and fused images (98.0%, 99.4%, 99.2%) yielded significantly higher diagnostic performance than that of CT alone (59.4%, 96.1%, 91.0%; P < 0.001). The cervical, supraclavicular, and extra-nodal regions were more accurately diagnosed with PET (P < 0.05), whereas the para-aortic to iliac regions were diagnosed more accurately with side-by-side reading and fused images than with CT alone or PET alone (P < 0.05).
  
  
  CONCLUSIONS
  Although fused images are clinically valuable, side-by-side reading showed equivalent performance, whereas the interpretation of PET alone yielded reasonably high diagnostic performance for restaging or follow-up of patients with malignant lymphoma.
authors.affiliation: Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan. aznogami@med.kobe-u.ac.jp
authors.forename: Munenobu
authors.initials: M
authors.lastname: Nogami
authors.forename: Yuji
authors.initials: Y
authors.lastname: Nakamoto
authors.forename: Setsu
authors.initials: S
authors.lastname: Sakamoto
authors.forename: Kazuto
authors.initials: K
authors.lastname: Fukushima
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Okada
authors.forename: Tsuneo
authors.initials: T
authors.lastname: Saga
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Higashi
authors.forename: Michio
authors.initials: M
authors.lastname: Senda
authors.forename: Toshimitsu
authors.initials: T
authors.lastname: Matsui
authors.forename: Kazuro
authors.initials: K
authors.lastname: Sugimura
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000473:pathology; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008228:Lymphoma, Non-Hodgkin / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D009367:Neoplasm Staging / Q000379:methods*; D049268:Positron-Emission Tomography / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*