Pericoronary adipose tissue attenuation assessed by dual-layer spectral detector computed tomography is a sensitive imaging marker of high-risk plaques

Abstract

Background: The pericoronary fat attenuation index (FAI) derived from conventional polychromatic computed tomography (CT) can capture the presence of coronary inflammation. However, conventional polychromatic CT has limitations in material component differentiation, and spectral CT could have a better ability to discriminate tissue characteristics. Hence, this study sought to assess pericoronary adipose tissue (PCAT) attenuation using spectral CT and explore its association with atherosclerotic plaque characteristics.Methods: We enrolled 104 patients with coronary atherosclerosis who met the inclusion criteria and underwent coronary CT angiography with dual-layer spectral detector computed tomography (SDCT).Plaque anatomical characteristics were measured, and the PCAT attenuation was assessed by polychromatic images (CT poly ), virtual mono-energetic images at 40 keV (CT 40 keV ), the slope of spectral attenuation curve (λ HU ), and the effective atomic number (Z eff ). The association of PCAT attenuation indicators with the presence of high-risk plaques was analyzed, along with the indicators' ability to identify high-risk plaques.Results: PCAT attenuation indicators around high-risk plaques were higher than those around nonhigh-risk plaques, especially CT 40 keV [−153.76±24.97 (non-high-risk plaque) vs. −119.87±22.74 (high-risk plaque), P<0.001]. CT 40 keV was a predictive factor of high-risk plaques, and high CT 40 keV (≥−120.60 HU) could assist in the identification of high-risk plaques, with an area under the curve of 0.883 (95% CI: 0.83-0.94, P<0.05).Conclusions: PCAT surrounding high-risk plaques showed higher attenuation; a finding that has been associated with coronary artery inflammation. The metrics derived from SDCT, especially CT40 keV , showed higher discriminatory power for detecting changes in PCAT attenuation than polychromatic CT. PCAT attenuation assessed by CT 40 keV may provide a novel imaging marker of plaque vulnerability.

Associations between the serum triglyceride-glucose index and pericoronary adipose tissue attenuation and plaque features using dual-layer spectral detector computed tomography: a cross- sectional study

“…This study showed that the FAI obtained by single-energy reconstruction at the low-energy end of the spectrum (40 keV) could better distinguish changes in the PCAT density. This result is consistent with the results of Rodriguez-Granillo et al [24] and our team [19,20]. We also observed similarities between λ HU and FAI 40keV , which may be a marker that re ects the in ammatory state of PCAT when the TyG index is elevated.…”

“…These results may help explain the mechanisms related to plaque progression and instability in patients with insulin resistance.Recently, a study demonstrated that double-layer spectral detector computed tomography (SDCT) is suitable for coronary CTAs [15], especially using virtual monochromatic imaging (VMI) reconstruction at a low-energy level (40 keV), which signi cantly increases the contrast of soft tissue [16,17,18]. Moreover, other studies have shown that SDCT is more sensitive and accurate for quantifying pericoronary adipose tissue (PCAT) than conventional computed tomography (CT) [19,20]. Therefore, we hypothesized that the PCAT index assessed by SDCT might be more helpful for distinguishing PCAT in ammation in patients with IR.Thus, we investigated associations between the pericoronary FAI and plaque features derived from SDCT and the serum TyG index level in patients to explore the possible mechanisms by which the TyG index affects coronary artery in ammation and plaque progression in IR.…”

“…Recently, a study demonstrated that double-layer spectral detector computed tomography (SDCT) is suitable for coronary CTAs [15], especially using virtual monochromatic imaging (VMI) reconstruction at a low-energy level (40 keV), which signi cantly increases the contrast of soft tissue [16,17,18]. Moreover, other studies have shown that SDCT is more sensitive and accurate for quantifying pericoronary adipose tissue (PCAT) than conventional computed tomography (CT) [19,20]. Therefore, we hypothesized that the PCAT index assessed by SDCT might be more helpful for distinguishing PCAT in ammation in patients with IR.…”

Association of Pericoronary Adipose Tissue Quality Determined by Dual-Layer Spectral Detector CT With Severity of Coronary Artery Disease: A Preliminary Study

“…This may suggest that PCAT surrounding the atherosclerotic plaques with non-calcified component has higher metabolically activity. This may be related to the characteristic of highly inflamed atherosclerotic plaque, which has been discussed in detail in another separate work of our research team ( 39 ). Interestingly, the opposite results were obtained in non-CAD cases, which showed that FAI 40keV adjacent to non-calcified plaques was the lowest, although the differences between the groups were not statistically significant.…”

Pre-diabetes is Associated with Attenuation rather than Volume of Epicardial Adipose Tissue on Computed Tomography

“…There is increasing evidence, that EATA is modulated by several factors, not only the regulation of brown adipose tissue-like features, but also local in ammation around the coronary arteries, i.e. in the pericoronary adipose tissue (PCAT) [41][42][43] . Augmented cellularity due to in ammation or an increase in extracellular matrix in brotic (post)in ammatory conditions 29 can increase EATA.…”