Abstract 682: Characterization of Coronary Atherosclerotic Plaque by Dual-Source Computed Tomography: Comparison with Optical Coherence Tomography
Background: Dual-source computed tomography (DSCT) is able to non-invasively visualize coronary artery with a high temporal and spatial resolution, and is expected to assess the tissue characters of the coronary atherosclerotic plaque (ASP). Optical coherence tomography (OCT) is a newly developed intravascular imaging modality with the highest spatial resolution of 10μm among clinically available modalities, and it can differentiate the pathohistological changes occurring in coronary ASP, including rupture-prone vulnerable plaque. Objective: To investigated the ability of DSCT for the assessment of the coronary ASP characteristics in the comparison with OCT.
Methods: In 7 patients with acute coronary syndrome, both DSCT and OCT were performed within 2 weeks after successful PCI. A total of 75 non-stenotic regions in non-culprit coronary arteries were classified by OCT findings as normal arterial wall (n=12), fibrous ASP (n=15), lipid-rich ASP with thick fibrous cap (ThCFA, n=23), lipid-rich ASP with thin fibrous cap (TCFA, n=19), and calcified ASP (n=6). For each region assessed by OCT, tissue characters of reconstructed DSCT images was classified into 4 groups, as normal arterial wall (wall thickness < 0.5mm), fibrous ASP (wall thickness > 0.5mm and CT value of 50–200 HU), lipid-rich ASP (0–50 HU) and calcified ASP (>500 HU).
Results: The CT values (HU) within fibrous, lipid-rich and calcified ASP classified by OCT were 64.7±14.6, 32.3±30.9, and 583.4±87.5, respectively. Based on the OCT diagnosis, sensitivity of DSCT on tissue characterization was 100% (12 of 12) for normal arterial wall, 66.7% (10 of 15) for fibrous ASP, 57.1% (24 of 42) for total lipid-rich ASP, and 83.3% (5 of 6) calcified ASP. For the detection of total lipid-rich ASP, specificity, positive predictive value, and negative predictive value of DSCT were 73.1%, 63.2%, and 67.9%, respectively. DSCT was not able to differentiate the lipid-rich ASP with TCFA from ThCFA based on CT value (34.6±28.3 vs. 29.2±35.2, p = 0.64).
Conclusion: DSCT is helpful for the noninvasive detection and characterization of atherosclerotic coronary plaque. However, further improvement of image quality should be necessary, especially for the detection of vulnerable coronary plaque.