Focal pericoronary adipose tissue attenuation is related to plaque presence, plaque type, and stenosis severity in coronary CTA

OBJECTIVES: To investigate the association of pericoronary adipose tissue mean attenuation (PCAT(MA)) with coronary artery disease (CAD) characteristics on coronary computed tomography angiography (CCTA). METHODS: We retrospectively investigated 165 symptomatic patients who underwent third-generation dual-source CCTA at 70kVp: 93 with and 72 without CAD (204 arteries with plaque, 291 without plaque). CCTA was evaluated for presence and characteristics of CAD per artery. PCAT(MA) was measured proximally and across the most severe stenosis. Patient-level, proximal PCAT(MA) was defined as the mean of the proximal PCAT(MA) of the three main coronary arteries. Analyses were performed on patient and vessel level. RESULTS: Mean proximal PCAT(MA) was −96.2 ± 7.1 HU and −95.6 ± 7.8HU for patients with and without CAD (p = 0.644). In arteries with plaque, proximal and lesion-specific PCAT(MA) was similar (−96.1 ± 9.6 HU, −95.9 ± 11.2 HU, p = 0.608). Lesion-specific PCAT(MA) of arteries with plaque (−94.7 HU) differed from proximal PCAT(MA) of arteries without plaque (−97.2 HU, p = 0.015). Minimal stenosis showed higher lesion-specific PCAT(MA) (−94.0 HU) than severe stenosis (−98.5 HU, p = 0.030). Lesion-specific PCAT(MA) of non-calcified, mixed, and calcified plaque was −96.5 HU, −94.6 HU, and −89.9 HU (p = 0.004). Vessel-based total plaque, lipid-rich necrotic core, and calcified plaque burden showed a very weak to moderate correlation with proximal PCAT(MA). CONCLUSIONS: Lesion-specific PCAT(MA) was higher in arteries with plaque than proximal PCAT(MA) in arteries without plaque. Lesion-specific PCAT(MA) was higher in non-calcified and mixed plaques compared to calcified plaques, and in minimal stenosis compared to severe; proximal PCAT(MA) did not show these relationships. This suggests that lesion-specific PCAT(MA) is related to plaque development and vulnerability. KEY POINTS: • In symptomatic patients undergoing CCTA at 70 kVp, PCAT(MA) was higher in coronary arteries with plaque than those without plaque. • PCAT(MA) was higher for non-calcified and mixed plaques compared to calcified plaques, and for minimal stenosis compared to severe stenosis. • In contrast to PCAT(MA) measurement of the proximal vessels, lesion-specific PCAT(MA) showed clear relationships with plaque presence and stenosis degree. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00330-021-07882-1.