Session S81.4

An Automated Approach to Quantify Volumetric Coronary Plaque Composition by Multi-Slice Computed Tomography: An Ex-Vivo Feasibility Study

N Bruining*, S Verheye, M Knaapen, P Somers, E Regar, J Ligthart, F Cademartiri,
S de Winter, G van Langenhove, PW Serruys, PJ de Feijter, R Hamers

Erasmus Medical Center
Rotterdam, Netherlands

Objectives: To explore the application of the Hounsfield unit (HU) distribution for quantitative coronary plaque tissue composition by multi-slice computed tomography (MSCT).
Background: Non-invasive quantitative coronary plaque compositional imaging would be a major advantage to study coronary artery disease.
Methods and Results: Ten human coronary left anterior descending (LAD) specimens were excised during autopsy and imaged by MSCT and optical coherence tomography (OCT), for later image registration to histopathology. The LAD’s were imaged with different concentrations of contrast in an olive oil bath, to simulate epicardial fat. Based on histopathology of each LAD performed at 5 mm intervals, a specimen showing a heterogeneous plaque composition was selected for comparative volumetric analysis between MSCT and histology. Seventy-five histological sections were taken within 5 sub-segments of 1.5mm length each at 5mm interspersed intervals. Quantitative volumetric plaque compositional analysis of MSCT data acquired with saline and medium contrast strength (300 HU) was compared to volumetric histopathology. MSCT plaque composition was defined as “soft”, “hard” and “calcium” based on the HU distribution and compared to histopathology-derived tissue components: smooth muscle cells (SMC), collagen and calcium, respectively. The saline scan showed as result: SMC’s vs. “soft”, 57.9% vs. 47.9%; collagen vs. “hard”: 37.2% vs. 33.1% and calcium vs. calcium 4.9% vs. 2.3%. With medium contrast strength the results were: 45.9%, 35.4% and 2.5, respectively.
Conclusion: The proposed method of quantitative volumetric plaque tissue composition by MSCT showed encouraging results in an ex-vivo setting.

(Abstract Control Number: 285)