Multi-parametric Algorithm for Epicardial Adipose Tissue Quantification in Patients with Non-Ischemic Heart Disease

Summary

Here, we present a protocol to quantify epicardial adipose tissue using non-contrast CT, providing a rapid, cost-effective, and contrast-free alternative to cardiac magnetic resonance for clinical and research applications.

Abstract

Epicardial adipose tissue (EAT), an active endocrine and paracrine organ, contributes to cardiovascular pathogenesis. While cardiac magnetic resonance (CMR) is the reference standard for quantifying EAT volume (EATV), its clinical utility is limited. Non-contrast chest CT (NCCT), widely used in radiology, offers a potential alternative. Although coronary CT angiography (CCTA) improves EAT-myocardial border delineation, its use is restricted by contrast allergy risks and increased radiation exposure. This study investigates the feasibility of NCCT for EATV assessment compared to CMR. We enrolled 120 non-ischemic heart disease patients undergoing both NCCT and CMR during a single hospitalization. EATV was measured using CMR-based volumetric analysis and NCCT-based grayscale threshold segmentation. EAT thickness was quantified at six anatomical sites (left/right atrioventricular grooves, anterior/posterior/superior interventricular grooves, and right ventricular free wall) on both modalities. Statistical analysis compared volume and thickness measurements. EATV derived from NCCT threshold segmentation showed no significant difference compared to CMR volumetry (P > 0.05). Similarly, EAT thickness measurements across all six sites demonstrated no significant differences between NCCT and CMR (all P > 0.05). NCCT-based grayscale threshold segmentation provides EATV measurements comparable to the CMR reference standard. This validates NCCT as a rapid, cost-effective, and clinically feasible alternative for accurate EAT quantification.

Introduction

Symptoms and signs in patients with non-ischemic heart disease are diverse and frequently misdiagnosed as non-cardiac conditions. Among patients undergoing invasive angiography for suspected ischemia, a substantial proportion (up to 70%) do not have obstructive coronary artery disease. Many of these patients exhibit symptoms consistent with ischemic presentations despite the absence of significant stenosis, falling under a broader spectrum of non-ischemic heart disease¹. In the Women's Ischemia Syndrome Evaluation-Coronary Vascular Dysfunction (WISE) study, which involved 883 female patients, approximately two-thirds (62%) lacked significan....

Protocol

Ethical approval for this study was granted by the Ethics Committee of Chengdu Medical College,with a waiver of informed consent. The study protocol ensured adherence to the ethical principles of the Declaration of Helsinki.

1. Patient selection

1. Use the following inclusion criteria:
   1. Include patients with non-ischemic heart disease (NIHD).
      NOTE: One hundred and twenty (120) patients with NIHD, who were treated at the First Affiliated Hospital of Chengdu Medical College between 2017 and 2024, were selected for this study.
   2. Ensure that all patients underwent both NCCT and CMR examinati....

Results

Table 1 presents the comparative analysis of EAT measurements between CT and MR modalities across all anatomical sites. Overall, the paired t-test demonstrated no significant differences (P > 0.05), supporting the equivalence of both methods. The mean differences (MR-CT) ranged from -0.10 mm (inferior interventricular groove) to +0.29 mm (left atrioventricular groove), with 95% confidence intervals consistently crossing zero. Volume measurements showed the smallest mean differen.......

Discussion

This finding demonstrates that, consistent with prior studies²³, the right atrioventricular groove (RAVG) exhibits the thickest epicardial adipose tissue (EAT) among the six measured anatomical sites. This may be attributed to hemodynamic differences between the right and left cardiac systems. The right ventricle pumps blood into the low-resistance pulmonary circulation, while the left ventricle must overcome high-resistance systemic vasculature, generating significantly higher pressures. Chronic .......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
640-slice CT scanner	United Imaging	uCT 960+	Established whole-organ volumetric CT with sub-millimeter isotropic resolution, enabling motion-free cardiac imaging and ultra-low dose tissue characterization.
3.0 T MRI scanner	United Imaging	uMR 960+	Advanced wide-bore platform delivering exceptional soft-tissue contrast for quantitative cardiac phenotyping and multi-parametric body composition analysis.
3D Slicer	Open-source community	https://www.slicer.org/	Free, open-source software for medical image analysis (segmentation, registration, 3D visualization). Supported by NIH.
PyTorch	Meta Platforms, Inc.	https://pytorch.org/	Open-source deep learning framework with dynamic computation graphs, widely used for AI research and model deployment. Supports GPU acceleration.