title: Restrictive allograft syndrome after lung transplantation: new radiological insights.
abstract: OBJECTIVE
  To describe the CT changes in patients with restrictive allograft syndrome (RAS) after lung transplantation, before and after clinical diagnosis.
  
  
  METHODS
  This retrospective study included 22 patients with clinical diagnosis of RAS. Diagnosis was based on a combination of forced expiratory volume (FEV1) decline (≥20 %) and total lung capacity (TLC) decline (≥10 %). All available CT scans after transplantation were analyzed for the appearance and evolution of lung abnormalities.
  
  
  RESULTS
  In 14 patients, non-regressing nodules and reticulations predominantly affecting the upper lobes developed an average of 13.9 months prior to the diagnosis of RAS. Median graft survival after onset of non-regressing abnormalities was 33.5 months, with most patients in follow-up (9/14). In eight patients, a sudden appearance of diffuse consolidations mainly affecting both upper and lower lobes was seen an average of 2.8 months prior to the diagnosis of RAS. Median graft survival was 6.4 months after first onset of non-regressing abnormalities, with graft loss in most patients (6/8).
  
  
  CONCLUSIONS
  RAS has been previously described as a homogenous group. However, our study shows two different groups of RAS-patients: one with slow progression and one with fast progression. The two groups show different onset and progression patterns of CT abnormalities.
  
  
  CONCLUSIONS
  • RAS is the newest discovered form of chronic lung allograft dysfunction (CLAD). • RAS is not a homogenous group, as survival varies greatly between patients. • In this study, we see two different CT onset and progression patterns. • These two different CT patterns also correlate with a different survival rate.
authors.affiliation: Department of Radiology, University Hospitals Leuven, Herestraat 49, 3000, Leuven, Belgium. adriana.dubbeldam@uzleuven.be.
authors.forename: Adriana
authors.identifier: http://orcid.org/0000-0002-7410-6495
authors.initials: A
authors.lastname: Dubbeldam
authors.affiliation: Department of Radiology, University Hospitals Leuven, Herestraat 49, 3000, Leuven, Belgium.
authors.forename: Caroline
authors.initials: C
authors.lastname: Barthels
authors.affiliation: Department of Radiology, University Hospitals Leuven, Herestraat 49, 3000, Leuven, Belgium.
authors.forename: Johan
authors.initials: J
authors.lastname: Coolen
authors.affiliation: Department of Radiology, University Hospitals Leuven, Herestraat 49, 3000, Leuven, Belgium.
authors.forename: Johny A
authors.initials: JA
authors.lastname: Verschakelen
authors.affiliation: Department of Pneumology, University Hospitals Leuven, Herestraat 49, 3000, Leuven, Belgium.
authors.forename: Stijn E
authors.initials: SE
authors.lastname: Verleden
authors.affiliation: Department of Pneumology, University Hospitals Leuven, Herestraat 49, 3000, Leuven, Belgium.
authors.forename: Robin
authors.initials: R
authors.lastname: Vos
authors.affiliation: Department of Pneumology, University Hospitals Leuven, Herestraat 49, 3000, Leuven, Belgium.
authors.forename: Geert M
authors.initials: GM
authors.lastname: Verleden
authors.affiliation: Department of Radiology, University Hospitals Leuven, Herestraat 49, 3000, Leuven, Belgium.
authors.forename: Walter
authors.initials: W
authors.lastname: De Wever
mesh_terms: D000293:Adolescent; D000328:Adult; D064591:Allografts; D001530:Belgium / Q000453:epidemiology; D002648:Child; D051799:Delayed Graft Function / Q000150:complications / Q000175:diagnosis* / Q000401:mortality; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume; D006085:Graft Survival; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging*; D016040:Lung Transplantation / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D011658:Pulmonary Fibrosis / Q000175:diagnosis* / Q000209:etiology / Q000401:mortality; D012129:Respiratory Function Tests; D012189:Retrospective Studies; D015996:Survival Rate / Q000639:trends; D013577:Syndrome; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014109:Total Lung Capacity; D055815:Young Adult
keywords: Computed tomography; Graft survival; Lung transplantation; Organizing pneumonia; Pulmonary fibrosis