Diffusion Tensor Imaging Application to Cardiovascular Magnetic Resonance Imaging

The work presented in this thesis concentrates on how to perform in vivo cardiac diffusion tensor imaging (DTI) by using magnetic resonance imaging (MRI). Translation of this technique (DTI) to moving organs such as the beating heart has become feasible, but remains a challenging task, occasionally leading to poor MRI signal intensity and accuracy. The first chapter outlines the anatomy and physiology of the human heart, linking the structure of cardiac muscle fiber to its function during contraction and relaxation. The macroscopic properties of cardiac muscle and structure of the myocardium are further discussed in this chapter. This will provide a deeper understanding of the myocardium architecture.;Chapter 2 describes the fundamental principles behind magnetic resonance imaging (MRI). The basic principles of spin properties, energy state, magnetization, and MR signal acquisition are also described in this chapter. Diffusion tensor MRI can be used to depict the anisotropy of tissue. Chapter 3 discusses the concept of diffusion tensor imaging and associated forms of motion together with their physical signi cance. Measurements of diff usion motion and their interpretation are necessarily tied to a mathematical description. Consequently, a detailed coverage of diff usion mathematical description, and diffusion signal attenuation equation are presented with the MR techniques for quantifying diffusion process.;Chapter 4 explores the feasibility of in vivo DTI of the human heart with the conventional spin echo pulse sequence. Echo planar imaging (EPI) acquisition in combination with parallel imaging method enables the single-shot spin echo diffusion sequence to collect in vivo diffusion-weighted images (DWI) within a single cardiac phase. 1-D navigator technique was used as a respiratory motion compensation to obtain DWIs within an accepted window for reducing the effect of respiration. Cardiac DTI was performed on healthy and well-motivated volunteers to evaluate the technique robustness and potential.;The aim of chapter 5 is to investigate the implementation of in vivo cardiac DTI using accelerated turbo spin echo (TSE) acquisition. DWIs acquired with this method displayed less geometrical variations, susceptibility, and eddy current artifacts across the myocardium of the LV. Consequently, in vivo cardiac DTI with turbo spin echo resulted in improved DWI quality and achieving more reliable quantitative diff usion metrics in myocardium.