Time-Resolved Contrast-Enhanced MR Angiography:
Rapid Imaging Techniques for Evaluation of the Peripheral Vasculature with MRI

Casey Johnson
Doctoral Candidate, Biomedical Engineering
Mayo Graduate School, Mayo Clinic, Rochester, MN

Magnetic resonance imaging (MRI) is a powerful method to see the interior of the human body.  Applications are broad, ranging from imaging the anatomical structure of the knee to the dynamics of blood oxygenation in the brain.  However, all MRI applications are based on the same key physical principles discovered by Nobel Prize-winning physicists in the mid-1900s.  Since the advent of MRI in 1973, researchers have delved into all aspects of the MRI experiment, making progress toward understanding the underlying physics, enhancing the hardware apparatus, designing novel ways to acquire data, and building algorithms to turn the raw data into images.  Advancements have been partly driven by the technical challenges of MR angiography (imaging of blood vessels).  These include the development of rapid imaging techniques such as time-resolved imaging, real-time imaging, and parallel imaging as well as hardware improvements such as higher field strengths, faster gradient coils, and receiver coil arrays.  This talk will be divided into two parts.  In the first part, I will provide an overview of the physics of MRI and describe how images are formed.  In the second part, I will focus on my recent work to image the vasculature of the legs with both high spatial and high temporal resolution using rapid imaging methods.