title: Pulmonary emphysema diagnosis with a preclinical small-animal X-ray dark-field scatter-contrast scanner.
abstract: OBJECTIVE
  To test the hypothesis that the joint distribution of x-ray transmission and dark-field signals obtained with a compact cone-beam preclinical scanner with a polychromatic source can be used to diagnose pulmonary emphysema in ex vivo murine lungs.
  
  
  METHODS
  The animal care committee approved this study. Three excised murine lungs with pulmonary emphysema and three excised murine control lungs were imaged ex vivo by using a grating-based micro-computed tomographic (CT) scanner. To evaluate the diagnostic value, the natural logarithm of relative transmission and the natural logarithm of dark-field scatter signal were plotted on a per-pixel basis on a scatterplot. Probability density function was fit to the joint distribution by using principle component analysis. An emphysema map was calculated based on the fitted probability density function.
  
  
  RESULTS
  The two-dimensional scatterplot showed a characteristic difference between control and emphysematous lungs. Control lungs had lower average median logarithmic transmission (-0.29 vs -0.18, P = .1) and lower average dark-field signal (-0.54 vs -0.37, P = .1) than emphysematous lungs. The angle to the vertical axis of the fitted regions also varied significantly (7.8° for control lungs vs 15.9° for emphysematous lungs). The calculated emphysema distribution map showed good agreement with histologic findings.
  
  
  CONCLUSIONS
  X-ray dark-field scatter images of murine lungs obtained with a preclinical scanner can be used in the diagnosis of pulmonary emphysema.
  
  
  BACKGROUND
  http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.13122413/-/DC1.
authors.affiliation: Department of Physics and Institute of Medical Engineering, Technische Universität München, James-Franck-Strasse 1, 85748 Garching, Germany; Institute of Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Munich, Germany; Comprehensive Pneumology Center, Institute of Lung Biology and Disease, Helmholtz Zentrum Munich and Ludwig-Maximilians-University Hospital Munich, Neuherberg, Germany.
authors.forename: Andre
authors.initials: A
authors.lastname: Yaroshenko
authors.forename: Felix G
authors.initials: FG
authors.lastname: Meinel
authors.forename: Martin
authors.initials: M
authors.lastname: Bech
authors.forename: Arne
authors.initials: A
authors.lastname: Tapfer
authors.forename: Astrid
authors.initials: A
authors.lastname: Velroyen
authors.forename: Simone
authors.initials: S
authors.lastname: Schleede
authors.forename: Sigrid
authors.initials: S
authors.lastname: Auweter
authors.forename: Alexander
authors.initials: A
authors.lastname: Bohla
authors.forename: Ali Ö
authors.initials: AÖ
authors.lastname: Yildirim
authors.forename: Konstantin
authors.initials: K
authors.lastname: Nikolaou
authors.forename: Fabian
authors.initials: F
authors.lastname: Bamberg
authors.forename: Oliver
authors.initials: O
authors.lastname: Eickelberg
authors.forename: Maximilian F
authors.initials: MF
authors.lastname: Reiser
authors.forename: Franz
authors.initials: F
authors.lastname: Pfeiffer
mesh_terms: D000818:Animals; D004867:Equipment Design; D005260:Female; D066298:In Vitro Techniques; D051379:Mice; D008810:Mice, Inbred C57BL; D011656:Pulmonary Emphysema / Q000000981:diagnostic imaging*; D011857:Radiographic Image Interpretation, Computer-Assisted; D055114:X-Ray Microtomography / Q000295:instrumentation / Q000379:methods*