title: High-resolution peripheral quantitative CT imaging: Cortical porosity, poor trabecular bone microarchitecture, and low bone strength in lung transplant recipients.
abstract: OBJECTIVE
  To characterize bone microarchitecture and quantify bone strength in lung transplant (LT) recipients by using high-resolution (HR) peripheral quantitative computed tomographic (CT) imaging of the ultradistal radius.
  
  
  METHODS
  After study approval by the local ethics committee, all participants provided written informed consent. Included were 118 participants (58 LT recipients [mean age, 46.8 years ± 1.9; 30 women, 28 men] and 60 control participants [mean age, 39.9 years ± 1.9; 41 women, 19 men]) between April 2010 and May 2012. HR peripheral quantitative CT of the ultradistal radius was performed and evaluated for bone mineral density and trabecular and cortical bone microarchitecture. Mechanical competence was quantified by microfinite element analysis. Differences between LT recipients and control participants were determined by using two-way factorial analysis of covariance with age adjustment.
  
  
  RESULTS
  Total and trabecular bone mineral density were significantly lower (-13.4% and -16.4%, respectively; P = .001) in LT recipients than in healthy control participants. LT recipients had lower trabecular number (-9.7%; P = .004) and lower trabecular thickness (-8.1%; P = .025). Trabecular separation and trabecular network heterogeneity were higher (+24.3% and +63.9%, respectively; P = .007 and P = .012, respectively) in LT recipients. Moreover, there was pronounced cortical porosity (+31.3%; P = .035) and lower cortical thickness (-10.2%, P = .005) after LT. In addition, mechanical competence was impaired, which was reflected by low stiffness (-15.0%; P < .001), low failure force (-14.8%; P < .001), and low bone strength (-14.6%; P < .001).
  
  
  CONCLUSIONS
  Men and women with recent LT showed severe deficits in cortical and trabecular bone microarchitecture. Poor bone microarchitecture and low bone strength are likely to contribute to high fracture susceptibility observed in LT recipients.
authors.affiliation: From the Computational Imaging Research Laboratory (L.F., A.V., M.D.D., F.K., G.L., J.M.P.), Division of Neuroradiology and Musculoskeletal Radiology (C.S.W., F.K., J.M.P.), Division of General and Paediatric Radiology (D.K., M.W.), and Christian Doppler Laboratory for Ophthalmic Image Analysis (L.F.), Department of Biomedical Imaging and Image-guided Therapy, Division of Thoracic Surgery (P.J., W.K., B.Z.), and Department of Pathophysiology and Allergy Research (P.P.), Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria; Medical Department II, St. Vincent Hospital Vienna, Vienna, Austria (H.R.); and Institute of Lightweight Design and Structural Biomechanics, Vienna University of Technology, Vienna, Austria (T.G.).
authors.forename: Lukas
authors.initials: L
authors.lastname: Fischer
authors.forename: Alexander
authors.initials: A
authors.lastname: Valentinitsch
authors.forename: Matthew D
authors.initials: MD
authors.lastname: DiFranco
authors.forename: Claudia
authors.initials: C
authors.lastname: Schueller-Weidekamm
authors.forename: Daniela
authors.initials: D
authors.lastname: Kienzl
authors.forename: Heinrich
authors.initials: H
authors.lastname: Resch
authors.forename: Thomas
authors.initials: T
authors.lastname: Gross
authors.forename: Michael
authors.initials: M
authors.lastname: Weber
authors.forename: Peter
authors.initials: P
authors.lastname: Jaksch
authors.forename: Walter
authors.initials: W
authors.lastname: Klepetko
authors.forename: Barbara
authors.initials: B
authors.lastname: Zweytick
authors.forename: Peter
authors.initials: P
authors.lastname: Pietschmann
authors.forename: Franz
authors.initials: F
authors.lastname: Kainberger
authors.forename: Georg
authors.initials: G
authors.lastname: Langs
authors.forename: Janina M
authors.initials: JM
authors.lastname: Patsch
mesh_terms: D000328:Adult; D015519:Bone Density; D005260:Female; D006801:Humans; D016040:Lung Transplantation; D008297:Male; D008875:Middle Aged; D016062:Porosity; D011446:Prospective Studies; D011884:Radius / Q000000981:diagnostic imaging* / Q000473:pathology*; D014057:Tomography, X-Ray Computed / Q000379:methods*