title: HRCT features of acute rejection in patients with bilateral lung transplantation: the usefulness of lesion distribution.
abstract: OBJECTIVE
  This study sought to evaluate the high-resolution computed tomography (HRCT) features of acute rejection and to assess the diagnostic accuracy of HRCT for acute rejection considering distribution of lesions in patients with bilateral lung transplantation (BLT).
  
  
  METHODS
  Between March 2010 and June 2012, 48 transbronchial lung biopsies (TBLBs) and HRCT were performed simultaneously in 26 patients who underwent BLT. We evaluated the presence of ground glass opacity (GGO), consolidation, nodule, bronchial wall thickening, interlobular septal thickening, pleural effusion, atelectasis, bronchiectasis, and cardiomegaly on the HRCT images. The distribution of lesions was analyzed according to bilaterality or upper/lower predominance. Acute rejection was determined on the basis of the pathologic results of TBLB. We evaluated potential correlations of HRCT features with acute rejection, then assessed overall diagnostic accuracy of various HRCT features in combination to diagnose acute rejection in the transplanted lung.
  
  
  RESULTS
  Among the 48 TBLBs, 8 were diagnosed as acute rejection (A1, 4 cases; A2, 2 cases; and A3, 2 cases) pathologically. Two A1 rejections and one A2 rejection appeared normal on computed tomography images. Without considering the distribution of lesions, interlobular septal thickening was significantly associated with acute rejection (P = .010) only. Regarding the distribution of lesions on HRCT images, not only interlobular septal thickening but also GGO was significantly associated with acute rejection (P < .05). The sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy of the HRCT scan in the evaluation of acute rejection were 50%, 97.5%, 80%, 90.1%, and 89.6%, when the bilateral GGO and interlobular septal thickening with lower predominance were considered as the positive finding.
  
  
  CONCLUSIONS
  HRCT findings considering lesion distribution could be a useful tool in diagnosing acute rejection in patients with BLT.
authors.affiliation: Department of Radiology and Research Institute of Radiological Science, Yonsei University Health System, Seoul, Republic of Korea.
authors.forename: C H
authors.initials: CH
authors.lastname: Park
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: H C
authors.initials: HC
authors.lastname: Paik
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: S J
authors.initials: SJ
authors.lastname: Haam
authors.affiliation: Department of Pathology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: B J
authors.initials: BJ
authors.lastname: Lim
authors.affiliation: Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: M K
authors.initials: MK
authors.lastname: Byun
authors.affiliation: Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: J A
authors.initials: JA
authors.lastname: Shin
authors.affiliation: Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: H J
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Department of Radiology and Research Institute of Radiological Science, Yonsei University Health System, Seoul, Republic of Korea.
authors.forename: S H
authors.initials: SH
authors.lastname: Hwang
authors.affiliation: Department of Radiology and Research Institute of Radiological Science, Yonsei University Health System, Seoul, Republic of Korea. Electronic address: thkim1@yuhs.ac.
authors.forename: T H
authors.initials: TH
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006084:Graft Rejection / Q000000981:diagnostic imaging*; D006801:Humans; D016040:Lung Transplantation; D008297:Male; D008875:Middle Aged; D014057:Tomography, X-Ray Computed / Q000379:methods*