Fatty acid composition MRI of epicardial adipose tissue: methods and detection of proinflammatory biomarkers in ST-segment elevation myocardial infarction patients

Abstract

Purpose: To develop a method for quantifying the fatty acid composition (FAC) of human epicardial adipose tissue (EAT) using accelerated MRI and identify its potential for detecting proinflammatory biomarkers in patients with ST‐segment elevation myocardial infarction (STEMI). Methods: A multi‐echo radial gradient‐echo sequence was developed for accelerated imaging during a breath hold using a locally low‐rank denoising technique to reconstruct undersampled images. FAC mapping was achieved by fitting the multi‐echo images to a multi‐resonance complex signal model based on triglyceride characterization. Validation of the method was assessed using a phantom comprised of multiple oils. In vivo imaging was performed in STEMI patients (n = 21; 14 males/seven females). FAC was quantified in EAT, subcutaneous AT, and abdominal visceral AT. Results: Phantom validation demonstrated strong correlations (r > 0.97) and statistical significance (p < 0.0001) between measured and reference proton density fat fraction and FAC values. In vivo imaging of STEMI patients revealed a distinct EAT FAC profile compared to subcutaneous AT and abdominal visceral AT. EAT FAC parameters had significant correlations with left ventricular (LV) end‐diastolic volume index (p < 0.05), LV end‐systolic volume index (p < 0.05), and LV mass index (p < 0.05). Conclusions: Accelerated MRI enabled accurate quantification of human EAT FAC. The relationships between the EAT FAC profile and LV structure and function in STEMI patients suggest the potential of EAT FAC MRI as a biomarker for adipose tissue quality and inflammatory status in cardiovascular disease.