Holger Hetterich MD, Presenter: Nothing to Disclose

Marian Willner, Abstract Co-Author: Nothing to Disclose

Julia Herzen, Abstract Co-Author: Nothing to Disclose

Christopher Habbel, Abstract Co-Author: Nothing to Disclose

Alexander Christian Hipp, Abstract Co-Author: Nothing to Disclose

Fabian Bamberg MD, MPH, Abstract Co-Author: Speakers Bureau, Bayer AG Speakers Bureau, Siemens AG Research Grant, Bayer AG Research Grant, Siemens AG

Tobias Saam MD, Abstract Co-Author: Research Grant, Diamed Medizintechnik GmbH Research Grant, Bayer AG

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

Franz Pfeiffer, Abstract Co-Author: Nothing to Disclose

Current clinical X-ray imaging technologies rely on absorption information only despite other contrast mechanisms that may provide complementary information. X-ray phase-contrast computed tomography (PCT) has demonstrated superior contrast in low absorbing materials like biological soft tissue. We hypothesized that PCT has the potential for comprehensive, improved assessment and characterization of coronary plaque in an experimental ex-vivo setting examining human coronary artery specimens using histopathology as standard of reference.

Experiments were carried out at a laboratory-based set up consisting of X-ray tube (35kV), grating-interferometer and detector. Tomographic absorption and phase-shift images were reconstructed with an effective pixel size of 100 µm. PCT data was evaluated by reviewers blinded to histopathology. Sensitivity, specificity and accuracy for the detection of fibrous (FIB), lipid-rich (LIP) and calcified (CAL) tissue as well as signal intensities quantified by phase-contrast Hounsfield units (HUp) were determined. Lumen, plaque and vessel area were obtained and compared to histopathology measurements.

Fifteen coronary arteries with 316 corresponding PCT and histopathology cross-sections were evaluated. Histopathology showed LIP in 30.7%, FIB in 82.9% and CAL in 56.0% segments. Plaque components were detected with a sensitivity of ≥95.9%, specificity of ≥94.5%, positive and negative predictive value of ≥88.6% and ≥94.7%, respectively. Inter-rater agreement was high with к≥0.91. HUp were significantly different for all tissue types with 39.9±16.8 for LIP, 61.7 ± 54.6 for FIB and 447.3 ± 437.9 for CAL (p.0.001). Receiver operating characteristic curves for the differentiation of FIB and LIP demonstrated an area under the curve of 0.87 for HUp and 0.77 for conventional HU (p<0.001). PCT showed a good correlation with histopathology in lumen, vessel and plaque area measurements with a Pearson’s R of ≥0.86.

PCT allows comprehensive and accurate assessment of coronary atherosclerosis in an ex-vivo setting. Future studies will determine its feasibility for in-vivo applications.

Currently PCT might serve as a non-destructive method for accurate ex-vivo assessment of coronary plaque in cardiovascular research.

Hetterich, H, Willner, M, Herzen, J, Habbel, C, Hipp, A, Bamberg, F, Saam, T, Reiser, M, Pfeiffer, F, Comprehensive Assessment of Coronary Artery Disease by X-ray Phase-Contrast Computed Tomography.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14017189.html