Holger Hetterich MD, Presenter: Nothing to Disclose

Marian Willner, Abstract Co-Author: Nothing to Disclose

Julia Herzen, Abstract Co-Author: Nothing to Disclose

Sandra Fill, 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

Franz Pfeiffer, Abstract Co-Author: Nothing to Disclose

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

X-ray imaging of vascular pathology relies on X-ray absorption as the source of tissue contrast. However, X-rays are also subject to other physical phenomena including phase-shift, which holds promise to provide substantially improved contrast in low-absorbing materials like biological soft tissue. Techniques for plaque characterization and classification in both in-vivo and ex-vivo imaging have been a major focus in cardiovascular research in the last decade. This study aims to provide evidence for the potential of phase contrast computed tomography (PCT) for tissue characterization and plaque classification in human carotid arteries

Human carotid artery specimens were examined at an experimental set-up consisting of X-ray tube (35kV) grating interferometer and detector. Histopathology served as standard of reference. In PCT important plaque components including fibrous (FIB), lipid-rich (LIP) and calcified (CAL) tissue were identified and plaques were classified according to modified AHA criteria as normal intima/type I-II, III, IV/V, VI, VII or VIII by reviewers blinded to histopathology data. Diagnostic accuracies for the detection and differentiation of plaque components and types were evaluated.

In total 81 corresponding PCT/histopathology sections were evaluated. FIB, LIP and CAL were detected with sensitivity, specificity and accuracy of ≥0.91. In histopathology normal intima/type I-II was present in 23 (28.4%), type III in 8 (9.9%), type IV/V in 12 (14.8%), VI in 10 (12.3%), type VII in 20 (24.6%) and type VIII in 8 (9.9%) of all cross-sections. Sensitivity, specificity and accuracy were high for all analyzed plaque types (all >0.88) with a good level of agreement (κ=0.81). Inter-observer variability was excellent with an intraclass correlation coefficient of 0.91 (κ=0.85).

Carotid atherosclerotic plaques can accurately be evaluated by PCT in an ex-vivo setting. Future studies will have to evaluate its potential in-vivo.

Phase-contrast computed tomography holds promise for improved, comprehensive assessment of cardiovascular disease including atherosclerotic plaque characterization.

Hetterich, H, Willner, M, Herzen, J, Fill, S, Bamberg, F, Saam, T, Pfeiffer, F, Reiser, M, X-ray Phase-contrast Computed Tomography: Characterization and Classification of Human Carotid Atherosclerosis.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14017276.html