Large field-of-view non-contrast-enhanced MR angiography

Peripheral arterial disease (PAD) is associated with systemic atherosclerotic disease, thereby requiring systemic angiographic study to ensure successful diagnosis and treatment. The obstacles in conventional X-ray angiography and contrast-enhanced (CE) magnetic resonance angiography (MRA) are well documented. In addition to the physical limitations of CE MRA, recent publications have shown a significant link between gadolinium-based MR contrast agents and nephrogenic systemic fibrosis (NSF), particularly in patients with decreased renal function. Patients with PAD are at increased risk of renal artery stenosis (RAS), which can result in decreased kidney function. All of these issues have motivated non-contrast-enhanced (NCE) MRA techniques for this patient population. The purpose of the research presented in this doctoral dissertation is the combination of a novel fat-water separation technique, called the balanced steady-state free precession (bSSFP) Dixon method, with the continuously moving table technique for large field-of-view (FOV) NCE MRA. This technique was first successfully tested in the legs and renal arteries in healthy volunteers in the absence of table motion. Following this successful proof-of-concept work, the diagnostic quality of the technique was compared to CE MRA, considered the "clinical best practice", in the renal vasculature in patients suspected of having RAS. Finally, following rigorous testing through simulation, the bSSFP Dixon method was tested on healthy volunteers using the continuously moving table technique. The successful results of this combination represent a world-first attempt in large FOV NCE MRA.