Andre Yaroshenko, Presenter: Nothing to Disclose

Astrid Velroyen, Abstract Co-Author: Nothing to Disclose

Katharina Hellbach MD, Abstract Co-Author: Nothing to Disclose

Martin Bech, Abstract Co-Author: Nothing to Disclose

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

Konstantin Nikolaou MD, Abstract Co-Author: Speakers Bureau, Siemens AG Speakers Bureau, Bracco Group Speakers Bureau, Bayer AG

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

Oliver Eickelberg, Abstract Co-Author: Nothing to Disclose

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

Franz Pfeiffer, Abstract Co-Author: Nothing to Disclose

The obtained results are proof-of-principle results, demonstrating the feasibility to acquire in vivo small-animal phase-contrast and dark-field CT scans with a grating interferometer. The obtained results reveal the high potential and diagnostic value of x-ray dark-field lung imaging. The estimated animal dose is compatible with longitudinal studies.

X-ray phase-contrast and dark-field imaging are two imaging modalities that have the potential to significantly increase the soft-tissue contrast and yield complementary information. Recently a method has been developed that makes it possible to acquire these imaging modalities with a conventional polychromatic laboratory source. The approach is based on the introduction of a three-grating Talbot-Lau interferometer into the beam. However, it has been questioned weather this approach is applicable for in vivo CT scans, where interferometer stability, image acquisition speed and patient dose have to be taken into account.

The dark-field CT reveals information about structures below the resolution limit of the system. Thus, dark-field can visualize the alveolar network of the lung. The regions affected by pulmonary emphysema could be clearly visualized and a substantial difference in the signal was observed compared to the healthy animal. Thus, dark-field CT offers additional diagnostic value for pulmonary imaging.

An in vivo CT of the thorax region of a healthy 10-week-old C57BL/6N mouse was acquired. Subsequently, a mouse with pulmonary emphysema was imaged. To induce a phenotype of human-like emphysema, a solution of pancreatic elastase was applied orotracheally (80 U per kilogram of body weight) to the mouse. During image acquisition the mice were breathing freely. The measurements were performed with a compact preclinical small-animal CT scanner. The scanner acquires conventional x-ray absorption simultaneously with phase-contrast and dark-field images. The reconstructed tomography results were evaluated with respect to the diagnostic value and compared to histological findings. The scan dose was estimated using a phantom.

Yaroshenko, A, Velroyen, A, Hellbach, K, Bech, M, Meinel, F, Nikolaou, K, Reiser, M, Eickelberg, O, Yildirim, A, Pfeiffer, F, In vivo X-ray Phase-contrast and Dark-field Small-animal CT Imaging.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14011034.html