Katharina Hellbach MD, Presenter: Nothing to Disclose

Andre Yaroshenko, Abstract Co-Author: Nothing to Disclose

Oliver Eickelberg, Abstract Co-Author: Nothing to Disclose

Martin Bech, Abstract Co-Author: Nothing to Disclose

Maximilian F. Reiser MD, Abstract Co-Author: Nothing to Disclose

Ali Onder Yildirim, Abstract Co-Author: Nothing to Disclose

Franz Pfeiffer, Abstract Co-Author: Nothing to Disclose

Felix G. Meinel MD, Abstract Co-Author: Nothing to Disclose

The aim of this study was to evaluate whether x-ray dark-field radiography can be used for early diagnosis of pulmonary emphysema in in vivo mice.

Emphysema was induced by orotracheal injection of porcine pancreatic elastase (80U/kg BW, n=30). Control mice (n=11) received orotracheal injection of PBS. To ensure the development of different stages of emphysema mice (female C57Bl/6N) were imaged 7, 14 and 21 days after application of elastase or PBS. Images were acquired with a prototype grating-based small animal scanner and processed using Fourier decomposition to generate transmission as well as dark-field radiographs. During image acquisition the anaesthetized mice were breathing freely. In vivo pulmonary function tests were performed before sacrificing the animals. Lungs were obtained for further histopathological analysis (e.g. mean cord length (MCL) quantification). Three blinded readers, all of them experienced radiologists and familiar with dark-field imaging, were asked to rate the severity of emphysema for both dark-field and transmission images.

Different stages of emphysema could be clearly visualized on the dark-field radiographs, contrary to the conventional absorption-based imaging. As confirmed by MCL-quantifications murine lungs in the elastase group had developed different stages of emphysema (figure 1). Correlation between MCL and dark-field signal intensity (r=0.85) was significantly higher than correlation between MCL and transmission signal intensity (r=0.37). Visual ratings for dark-field images (r=0.85) correlated significantly better with MCL than visual ratings for transmission images (r=0.36). Quantitative and qualitative diagnostic accuracy as well as interreader agreement were significantly higher for dark-field imaging than for conventional transmission images.

Using X-ray dark-field radiography it is possible to visualize and reliably diagnose different stages of emphysema in vivo with a projection imaging method.

Small structural changes in the lung can be visualized with the x-ray dark-field imaging. Using this imaging method it is possible to diagnose early emphysema using a projection imaging method, which offers the change to start therapy even before clinical symptoms occur. With further technical developments X-ray dark-field radiography could be used for emphysema screenings and follow-up imaging without the use of CT.

Hellbach, K, Yaroshenko, A, Eickelberg, O, Bech, M, Reiser, M, Yildirim, A, Pfeiffer, F, Meinel, F, Quantitative in Vivo X-ray Dark-field Radiography for Early Pulmonary Emphysema Diagnosis.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14045637.html