title: Cryptogenic organizing pneumonia: serial high-resolution CT findings in 22 patients.
abstract: OBJECTIVE
  We conducted a review of serial high-resolution CT (HRCT) findings of cryptogenic organizing pneumonia (COP).
  
  
  METHODS
  Over the course of 14 years, we saw 32 patients with biopsy-confirmed COP. Serial HRCT scans were available for only 22 patients (seven men and 15 women; mean age, 52 years; median follow-up period, 8 months; range, 5-135 months). Serial CT scans were evaluated by two chest radiologists who reached a conclusion by consensus. Overall changes in disease extent were classified as cured, improved (i.e., ≥ 10% decrease in extent), not changed, or progressed (i.e., ≥ 10% increase in extent). When there were remaining abnormalities, the final follow-up CT images were analyzed to express observers' ideas regarding what type of interstitial lung disease the images most likely suggested.
  
  
  RESULTS
  The two most common patterns of lung abnormality on initial scans were ground-glass opacification (86% of patients [19/22]) and consolidation (77% of patients [17/22]), distributed along the bronchovascular bundles or subpleural lungs in 13 patients (59%). In six patients (27%), the disease disappeared completely; in 15 patients (68%), the disease was decreased in extent; and in one patient (5%), no change in extent was detected on follow-up CT. When lesions remained, the final follow-up CT findings were reminiscent of fibrotic nonspecific interstitial pneumonia in 10 of 16 patients (63%).
  
  
  CONCLUSIONS
  Although COP is a disease with a generally good prognosis, most patients (73%) with COP have some remaining disease seen on follow-up CT scans, and, in such cases, the lesions generally resemble a fibrotic nonspecific interstitial pneumonia pattern.
authors.affiliation: Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Kangnam-Ku, Seoul 135-710, Republic of Korea.
authors.forename: Ju Won
authors.initials: JW
authors.lastname: Lee
authors.forename: Kyung Soo
authors.initials: KS
authors.lastname: Lee
authors.forename: Ho Yun
authors.initials: HY
authors.lastname: Lee
authors.forename: Man Pyo
authors.initials: MP
authors.lastname: Chung
authors.forename: Chin A
authors.initials: CA
authors.lastname: Yi
authors.forename: Tae Sung
authors.initials: TS
authors.lastname: Kim
authors.forename: Myung Jin
authors.initials: MJ
authors.lastname: Chung
mesh_terms: D018549:Cryptogenic Organizing Pneumonia / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods