CEST MRI reveals a correlation between visceral fat mass and reduced myocardial creatine in obese individuals despite preserved ventricular structure and function

Abstract

Systolic cardiac function is typically preserved in obese adults, potentially masking underlying declines in cardiomyocyte metabolism that may contribute to heart failure. We used chemical exchange saturation transfer (CEST) MRI, a sensitive method for measurement of myocardial creatine, to examine whether myocardial creatine levels correlate with cardiac structure, contractile function, or visceral fat mass in obese adults. In this study, obese (body mass index, BMI > 30, n = 20) and healthy (BMI < 25, n = 11) adults were examined with dual‐energy x‐ray absorptiometry to quantify fat masses. Cine MRI and myocardial tagging were performed at 1.5 T to measure ventricular structure and global function. CEST imaging with offsets in the range of ±10 parts per million (ppm) were performed in one mid‐ventricular slice, where creatine CEST contrast was calculated at 1.8 ppm following field homogeneity correction. Ventricular structure, global function (ejection fraction 69.4 ± 4.3% healthy versus 69.6 ± 9.3% obese, NS), and circumferential strain (−17.0 ± 2.3% healthy versus −16.5 ± 1.5% obese, NS) and strain rate were preserved in obese adults. However, creatine CEST contrast was significantly reduced in obese adults (6.8 ± 1.3% healthy versus 4.1 ± 2.7% obese, p = 0.001). Creatine CEST contrast was inversely correlated with total body fat% (ρ = −0.45, p = 0.011), visceral fat mass (ρ = −0.58, p = 0.001), and septal wall thickness (ρ = −0.44, p = 0.013), but uncorrelated to ventricular function or contractile function. In conclusion, creatine CEST‐MRI reveals a strong correlation between heightened body and visceral fat masses and reduced myocardial metabolic function that is independent of ventricular structure and global function in obese adults.

Quantifying the fractional concentrations and exchange rates of small‐linewidth CEST agents using the QUCESOP method under multi‐solute conditions in MRI signals

“…CEST technique may be helpful in the diagnosis and evaluation of the muscle diseases. Recently, some preliminary studies have shown the potential of the CEST technique on muscle diseases by creatine‐weighted CEST imaging 32,33,59‐62 . It is probably worthy and feasible to measure the local creatine and/or phosphocreatine concentration in muscle tissue by applying the QUCESOP method.…”

“…Recently, some preliminary studies have shown the potential of the CEST technique on muscle diseases by creatine-weighted CEST imaging. 32,33,[59][60][61][62] It is probably worthy and feasible to measure the local creatine and/ or phosphocreatine concentration in muscle tissue by applying the QUCESOP method. In addition, the k b of creatine and/or phosphocreatine may act as a good indicator of the local pH.…”

Demonstration of fast and equilibrium human muscle creatine CEST imaging at 3 T

“…Chemical exchange saturation transfer (CEST) MRI has been demonstrated as a promising technique to image endogenous metabolites/compounds and pH changes in disorders like brain tumors, epilepsy, and acute stroke 1–4 . Notably, there have been emerging applications of creatine CEST (CrCEST) MRI by detecting creatine guanidinium proton exchange at 1.8 ppm from the bulk water resonance 5–14 . However, the CEST measurement is highly variable, depending on both tissue properties and scan parameters 15,16 .…”

“…[1][2][3][4] Notably, there have been emerging applications of creatine CEST (CrCEST) MRI by detecting creatine guanidinium proton exchange at 1.8 ppm from the bulk water resonance. [5][6][7][8][9][10][11][12][13][14] However, the CEST measurement is highly variable, depending on both tissue properties and scan parameters. 15,16 Furthermore, although the RF irradiation amplitude has been long studied, it is necessary to note that RF saturation time (Ts) and the relaxation delay (Td) also affect the CEST measurements.…”

Nonenhanced Chemical Exchange Saturation Transfer Cardiac Magnetic Resonance Imaging in Patients With Amyloid Light‐Chain Amyloidosis

“…11,12 Chemical exchange saturation transfer (CEST) is an emerging metabolic technique to map creatine distribution in the myocardium. [13][14][15][16] A preliminary study has presented a clinically translatable contrast-free CEST technique validated in an animal model and in patients with chronic myocardial infarction. 17 Thus, the aim of this study was to investigate the feasibility of this CEST imaging technique in AL amyloidosis patients.…”