Department of Radiological Sciences, University of California, Irvine, Orange, CA 92868-3298, USA.
Acad Radiol. 2011 Aug;18(8):977-83. doi: 10.1016/j.acra.2011.03.011. Epub 2011 Jun 11.
Epicardial adipose tissue (EAT) is an important structure both as an active secretor of hormones and cytokines that play a role in the development of atherosclerosis, as well as its potential as a cardiac risk marker. The purpose of this article was to determine an easy but accurate quantification of EAT for routine clinical use.
We randomly selected coronary computed tomography angiographies of 60 patients (20 lean, 20 overweight, and 20 obese) derived from a larger study. Systolic and diastolic surface areas (SAs) were measured at two axial levels: a) fat pocket (FP) between right atrium and right ventricular outflow tract at origin of right coronary artery (RCA-FP) and b) FP anterior to right ventricular free wall (RVFW-FP) at coronary sinus ostium level. Maximum RVFW-FP thickness and total diastolic EAT volume were measured. EAT SA and thickness measurements were correlated to EAT volume and compared. Both interobserver and intraobserver reliability were assessed for SA and thickness with the intraclass correlation coefficient (ICC) as well as mean relative difference ± standard deviation (SD). Differences between systolic and diastolic SA measurements were also evaluated. Diastolic RCA-FP showed the highest SA correlation with volume (ρ = 0.92) and compared to the correlation of EAT thickness with volume (ρ=0.59) demonstrated the largest difference in correlation (+ 0.33, P < .0001). Systolic RCA-FP, systolic RVFW-FP, and diastolic RVFW-FP correlations to volume were less than diastolic RCA-FP (ρ = 0.84, ρ = 0.82, ρ = 0.86 respectively), but all correlations were statistically significantly higher than EAT thickness with volume. Values of systolic SA were mildly higher than diastolic SA for the RCA-FP (relative difference ± SD = 1.8 ± 21%, P = .8), but significantly higher for the RVFW-FP (relative difference ± SD = 17 ± 35%, P < .0001). Both systolic and diastolic SA measurements showed excellent reproducibility (ICC >0.95). However, for EAT thickness, the inter-observer reliability was comparatively low (ICC = 0.66).
Diastolic RCA-FP SA is a quick, reproducible estimate of total EAT and compared to EAT thickness demonstrates a significantly better correlation with EAT volume.
心外膜脂肪组织（EAT）是一种重要的结构，它既是激素和细胞因子的活性分泌者，这些物质在动脉粥样硬化的发展中发挥作用，又是心脏风险标志物的潜在来源。本文的目的是确定一种简单但准确的 EAT 定量方法，以便于常规临床使用。
我们从一项更大的研究中随机选择了 60 例冠状动脉计算机断层血管造影术（CTA）患者（20 例瘦、20 例超重和 20 例肥胖）。在两个轴向水平测量收缩期和舒张期表面积（SA）：a）右心房和右心室流出道之间的脂肪袋（FP），在右冠状动脉（RCA）起源处（RCA-FP），b）冠状窦开口水平右心室游离壁（RVFW）前的 FP（RVFW-FP）。测量最大 RVFW-FP 厚度和总舒张期 EAT 体积。比较 EAT SA 和厚度测量值与 EAT 体积的相关性。采用组内相关系数（ICC）和平均相对差异±标准差（SD）评估 SA 和厚度的观察者间和观察者内可靠性。还评估了收缩期和舒张期 SA 测量之间的差异。舒张期 RCA-FP 与体积的相关性最高（ρ=0.92），与 EAT 厚度与体积的相关性相比（ρ=0.59），差异最大（+0.33，P<.0001）。收缩期 RCA-FP、收缩期 RVFW-FP 和舒张期 RVFW-FP 与体积的相关性均低于舒张期 RCA-FP（ρ=0.84、ρ=0.82、ρ=0.86），但所有相关性均明显高于 EAT 厚度与体积的相关性。对于 RCA-FP，收缩期 SA 值略高于舒张期 SA 值（相对差异±SD=1.8±21%，P=.8），但对于 RVFW-FP，差异显著（相对差异±SD=17±35%，P<.0001）。收缩期和舒张期 SA 测量均具有极好的可重复性（ICC>0.95）。然而，对于 EAT 厚度，观察者间可靠性相对较低（ICC=0.66）。
舒张期 RCA-FP SA 是 EAT 的一种快速、可重复的估计值，与 EAT 厚度相比，与 EAT 体积具有更好的相关性。
