AJR:199, September 2012 581 and treatment compared with infectious com- plications, the diagnosis and management of which have improved markedly [6, 7]. The pathophysiology of late-onset noninfectious pulmonary complications is not clearly under- stood, but graft-versus-host disease (GVHD) is inextricably linked with these complications. Chronic GVHD has proved to be the only im- portant risk factor for the development of late- onset noninfectious pulmonary complications, and most patients with these complications have responded to treatment with corticoste- roids and immunosuppressive drugs [6, 8]. Late-onset noninfectious pulmonary com- plications encompass a number of entities. Palmas et al. [7] proposed that these compli- cations include bronchiolitis obliterans (BO), BO with organizing pneumonia (BOOP), diffuse alveolar damage (DAD), lympho- CT Findings of Late-Onset Noninfectious Pulmonary Complications in Patients With Pathologically Proven Graft-Versus- Host Disease After Allogeneic Stem Cell Transplant Inyoung Song 1 Chin A Yi 1 Joungho Han 2 Dong Hwan Kim 3 Kyung Soo Lee 1 Tae Sung Kim 1 Myung Jin Chung 1 Song I, Yi CA, Han J, et al. 1 Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50, Ilwon-dong, Gangnam-gu, Seoul 135-701, Korea. Address correspondence to C. A. Yi (cayi@skku.edu). 2 Department of Pathology of Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea. 3 Department of Medical Oncology and Hematology, Princess Margaret Hospital, University of Toronto, Toronto, ON, Canada. Cardiopulmonary฀Imaging฀•฀Original฀Research AJR 2012; 199:581–587 0361–803X/12/1993–581 © American Roentgen Ray Society T he widespread use of prophylactic antibiotics and various techniques to monitor infections has helped to decrease infectious complica- tions in patients who undergo allogeneic stem cell transplant (SCT). However, clinically sig- nificant pulmonary complications occur in 40– 60% of patients who undergo allogeneic SCT, and these complications cause 10–40% of all transplant-related deaths [1–5]. Pulmonary complications can be categorized as infectious and noninfectious according to cause and can be categorized as early and late by lapse of time after SCT. Late-onset noninfectious pul- monary complications include noninfectious pulmonary complications that occur more than 3 months after allogeneic SCT. They are now recognized as life-threatening complications because of the relative difficulty in diagnosis Keywords: bronchiolitis obliterans, graft-versus-host disease, hematopoietic stem cell transplant, lung disease DOI:10.2214/AJR.11.7165 Received May 5, 2011; accepted after revision January 20, 2012. OBJECTIVE. We retrospectively analyzed the CT features of late-onset noninfectious pulmonary complications in patients with pathologically proven graft-versus-host disease (GVHD) after allogeneic stem cell transplant (SCT). MATERIALS฀AND฀METHODS. We analyzed the CT features of late-onset noninfec- tious pulmonary complications in 14 patients with pathologic diagnoses of GVHD who sur- vived disease free for more than 3 months after SCT. Late-onset noninfectious pulmonary complications were diagnosed by excluding pulmonary infection in these patients with respi- ratory symptoms and signs. The presence, extent, and distribution of CT features were evalu- ated in terms of geographic hypoattenuation, expiratory airtrapping, ground-glass attenuation (GGA), reticulation, crazy paving pattern, bronchiectasis, nodules, and honeycombing. Fur- ther disease classification was made on the basis of clinical, radiologic, and pulmonary func- tion test results and histologic findings. The longitudinal changes of late-onset noninfectious pulmonary complications were followed with CT. RESULTS. The 14 patients with late-onset noninfectious pulmonary complications were classified into subgroups with bronchiolitis obliterans (BO) (n = 7), nonclassifiable intersti- tial pneumonia (n = 5), and combined BO and nonclassifiable interstitial pneumonia (n = 2). The CT features of nonclassifiable interstitial pneumonia were GGA (5/7, 71%), reticulation (4/7, 57%), and crazy paving pattern (4/7, 57%) with a peribronchovascular distribution (6/7, 86%). All patients with nonclassifiable interstitial pneumonia had progression of disease with an increased extent of traction bronchiectasis, reticulation, and honeycombing on follow-up CT scans (median follow-up period, 22 months). CONCLUSION. Although not commonly encountered, nonclassifiable interstitial pneu- monia as a pattern of chronic GVHD should be included in the differential diagnosis of unex- plained peribronchial GGA or progressive traction bronchiectasis after SCT. Song et al. CT After Stem Cell Transplant Cardiopulmonary Imaging Original Research Downloaded from www.ajronline.org by 52.73.204.196 on 05/17/22 from IP address 52.73.204.196. Copyright ARRS. For personal use only; all rights reserved