Astrid Velroyen, Presenter: Nothing to Disclose

Andre Yaroshenko, Abstract Co-Author: Nothing to Disclose

Arne Tapfer, Abstract Co-Author: Nothing to Disclose

Martin Bech, Abstract Co-Author: Nothing to Disclose

Mark Muller, Abstract Co-Author: Nothing to Disclose

Bart Pauwels, Abstract Co-Author: Nothing to Disclose

Jeroen Hostens, Abstract Co-Author: Nothing to Disclose

Peter Bruyndonckx, Abstract Co-Author: Nothing to Disclose

Xuan Liu, Abstract Co-Author: Nothing to Disclose

Alexander Sasov, Abstract Co-Author: Nothing to Disclose

Franz Pfeiffer, Abstract Co-Author: Nothing to Disclose

In the last years, x-ray phase-contrast and dark-field imaging have been proven to provide superior soft-tissue contrast and complementary information in comparison to conventional attenuation-based imaging, thus great potential for medical imaging is anticipated. As a first step towards clinical implementation, we have developed a grating-based compact preclinical phase-contrast CT scanner with rotating gantry [1], from which we present novel results.

Our preclinical phase-contrast CT scanner is the first one to comprise a laboratory x-ray source, a detector and a three-grating interferometer installed on a rotating gantry. The interferometer is used to transfer minimal, sample-induced directional changes of the x-rays into intensity variations on the detector. From those measurements, the two new contrast modalities, i. e. phase-contrast, which is based on the refraction of x-rays, and dark-field contrast, which indicates microstructured regions that scatter x-rays, are obtained in addition to the attenuation-based image. [2, 3] By acquiring reference CT scans we studied thermal and rotation-induced instabilities that compromise the precise alignment and relative movement of the fine interferometric structures and thus cause image artifacts. Newly developed software tools are presented that allow to regain accurate images despite those instabilities. Also, technological advances that improve visibility and scanner performance in general are shown.  

We show CT scans of several biological samples and phantoms to demonstrate the possibilities of the new system. First planar radiographic images of a living mouse in differential phase, dark-field and attenuation contrast are presented, as well as phase-contrast ex-vivo mouse CT images made possible by the software and hardware improvements introduced to the scanner.

Our measurements clearly show the improved soft-tissue contrast and complementary information that can be obtained by phase and dark-field imaging in comparison to the conventional attenuation image. [1] Tapfer et al. PNAS 2012. [2] Pfeiffer et al. Nat Phys 2006. [3] Pfeiffer et al. Nat Mater 2008.  

By proving the feasibility of phase-sensitive imaging with a compact rotating gantry, this work represents an important milestone in translating phase-contrast from bench to bedside.

Velroyen, A, Yaroshenko, A, Tapfer, A, Bech, M, Muller, M, Pauwels, B, Hostens, J, Bruyndonckx, P, Liu, X, Sasov, A, Pfeiffer, F, Novel Results from a First Preclinical X-ray Phase-contrast CT Scanner.  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13023958.html