Development of proton magnetic resonance spectroscopy in human heart at 3 Tesla

Thesis

Cardiovascular magnetic resonance imaging (MRI) is a well established technique in clinical cardiology. Different MRI sequences are routinely used to assess cardiac anatomy, function, viability and other parameters that aid diagnosing cardiac disease. Conversely, cardiac magnetic resonance spectroscopy (MRS), the only available method for a non-invasive study of human cardiac metabolism, has not evolved into a clinical tool yet. The combination of both techniques holds great potential to gain insight into the causality of cardiomyopathy diseases or other medical conditions with high cardiovascular risk profile, like diabetes or obesity and improve the clinical management of cardiac diseases.

Nowadays, high field clinical MR systems have the great potential of improving the low spatial and temporal resolution and reproducibility of MRS. The aim of this thesis was to develop and implement a cardiac 1H-MRS method at 3 T that can be applied in clinical routine for the assessment of creatine and lipid levels in the human myocardium. The methodological developments to advance cardiac MRS are presented first. A robust 1H-MRS method comprising an optimized single-voxel technique, phased-array coil combination routine, optimized water suppression, breath-hold averaging and post-processing methods were developed. First, reproducibility and feasibility of the method were validated in vivo by acquiring 1H-MRS of the liver in almost one hundred healthy subjects. Subsequently, myocardial lipids levels were obtained in healthy volunteers by single breath-hold 1H-MRS triggered to mid-diastole, showing good reproducibility in an acquisition time less than 12 s. The good spectral resolution achieved using this method was demonstrated by the ability to differentiate for the first time two pools of myocardial lipids in spectra from the septum of patients with suspected myocardial lipid excess. Finally, creatine levels for healthy volunteers were investigated using multiple breath-hold acquisitions. Thus, this study shows the practicality and feasibility to incorporate this rapid cardiac 1H-MRS method into clinical studies of the human myocardium.

Authors: Rial Franco, B; Belen Rial Franco

• Publication date: 2010
• DOI: 10.5287/ora-0089b0r67
• Type of award: DPhil
• Level of award: Doctoral
• Awarding institution: Oxford University, UK
• Language: English
• Keywords: creatine; cardiac magnetic resonace spectroscopy; lipid; quantification; 3 Tesla
• Subjects: NMR spectroscopy; Medical sciences; Cardiovascular disease