title: Lung tumors on multimodal radiographs derived from grating-based X-ray imaging--a feasibility study.
abstract: OBJECTIVE
  The purpose of this study was to assess whether grating-based X-ray imaging may have a role in imaging of pulmonary nodules on radiographs.
  
  
  METHODS
  A mouse lung containing multiple lung tumors was imaged using a small-animal scanner with a conventional X-ray source and a grating interferometer for phase-contrast imaging. We qualitatively compared the signal characteristics of lung nodules on transmission, dark-field and phase-contrast images. Furthermore, we quantitatively compared signal characteristics of lung tumors and the adjacent lung tissue and calculated the corresponding contrast-to-noise ratios.
  
  
  RESULTS
  Of the 5 tumors visualized on the transmission image, 3/5 tumors were clearly visualized and 1 tumor was faintly visualized in the dark-field image as areas of decreased small angle scattering. In the phase-contrast images, 3/5 tumors were clearly visualized, while the remaining 2 tumors were faintly visualized by the phase-shift occurring at their edges. No additional tumors were visualized in either the dark-field or phase-contrast images. Compared to the adjacent lung tissue, lung tumors were characterized by a significant decrease in transmission signal (median 0.86 vs. 0.91, p = 0.04) and increase in dark-field signal (median 0.71 vs. 0.65, p = 0.04). Median contrast-to-noise ratios for the visualization of lung nodules were 4.4 for transmission images and 1.7 for dark-field images (p = 0.04).
  
  
  CONCLUSIONS
  Lung nodules can be visualized on all three radiograph modalities derived from grating-based X-ray imaging. However, our initial data suggest that grating-based multimodal X-ray imaging does not increase the sensitivity of chest radiographs for the detection of lung nodules.
authors: Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Marchioninistr. 15, 81377 München, Germany. Electronic address: felix.meinel@med.uni-muenchen.de.
authors: Felix G
authors: FG
authors: Meinel
authors: Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Marchioninistr. 15, 81377 München, Germany.
authors: Felix
authors: F
authors: Schwab
authors: Department of Physics and Institute of Medical Engineering, Technische Universität München, James-Franck-Straße 1, 85748 Garching, Germany.
authors: Andre
authors: A
authors: Yaroshenko
authors: Department of Physics and Institute of Medical Engineering, Technische Universität München, James-Franck-Straße 1, 85748 Garching, Germany.
authors: Astrid
authors: A
authors: Velroyen
authors: Department of Physics and Institute of Medical Engineering, Technische Universität München, James-Franck-Straße 1, 85748 Garching, Germany; Medical Radiation Physics, Lund University, 22185 Lund, Sweden.
authors: Martin
authors: M
authors: Bech
authors: Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Marchioninistr. 15, 81377 München, Germany.
authors: Katharina
authors: K
authors: Hellbach
authors: Molecular Oncology Unit, Philipps-University Marburg, D-35032 Marburg, Germany.
authors: Jeanette
authors: J
authors: Fuchs
authors: Molecular Oncology Unit, Philipps-University Marburg, D-35032 Marburg, Germany.
authors: Thorsten
authors: T
authors: Stiewe
authors: Comprehensive Pneumology Center, Institute of Lung Biology and Disease, Helmholtz Zentrum Munich, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany.
authors: Ali Ö
authors: AÖ
authors: Yildirim
authors: Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Marchioninistr. 15, 81377 München, Germany.
authors: Fabian
authors: F
authors: Bamberg
authors: Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Marchioninistr. 15, 81377 München, Germany.
authors: Maximilian F
authors: MF
authors: Reiser
authors: Department of Physics and Institute of Medical Engineering, Technische Universität München, James-Franck-Straße 1, 85748 Garching, Germany.
authors: Franz
authors: F
authors: Pfeiffer
authors: Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Marchioninistr. 15, 81377 München, Germany.
authors: Konstantin
authors: K
authors: Nikolaou
mesh_terms: D000818:Animals; D005240:Feasibility Studies; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D051379:Mice; D064847:Multimodal Imaging / Q000379:methods*; D011829:Radiation Dosage; D059629:Signal-To-Noise Ratio; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: Chest radiography; Lung tumors; X-ray dark-field imaging; X-ray phase-contrast imaging