3T-MRH1 spectroscopy for quantification of myocardial steatosis: relationship to metabolic profile and global myocardial function

Abstract

Methods A research protocol was applied on 90 subjects, using a Siemens Verio 70 cm bore 3T-MRI scanner. All subjects were not known to have cardiac disease. MR spectroscopy was performed with water suppressed ECG gated point resolved spectroscopy (PRESS), TR/TE =1R-R/ 30ms. PRESS voxel was located in the septum at isovolumic phase of diastole. Short axis and 4-chamber Steady State Free Precession (SSFP) cine images were obtained to prescribe the PRESS voxel location, and saturation slabs across subcutaneous and pericardial fat were used. A breathing navigator was set on the dome of the diaphragm on a free breathing scout to reduce the breathing effects. B0 shimming parameters were optimized with a (breath-hold) rapid B0 mapping method. Fat content was quantified with Amares/MRUI and related to water in unsuppressed spectra. SSFP images were used for evaluation of global myocardial function (ejection fraction, end diastolic volume, end systolic volume, stroke volume and cardiac output). Variables were indexed to BSA. All subjects had same day metabolic profile evaluation, included insulin sensitivity, fasting glucose level, resting energy expenditure, maximum VO2, regional fat percentage and waist circumference. Lipid profile including serum cholesterol, HDL, LDL and serum triglycerides was obtained within one month of the scan.