Developing Real-time MRI Using Simultaneous Multislice Acceleration and Compressed Sensing

Real-time MRI (rtMRI) is an imaging method which allows motion to be recorded at high temporal and spatial resolutions without the need for synchronization equipment or assumptions regarding periodicity of motion. This has a wide range of applications such as studying the dynamics of speech, swallowing and joint movement. To achieve a high temporal resolution, rtMRI methods typically employ fast imaging sequences combined with highly undersampled non-Cartesian k-space sampling. The need for fast data acquisition prevents multiple slices from being acquired without loss of temporal resolution, limiting the anatomical coverage of rtMRI.

This thesis describes the development of an rtMRI sequence which uses radial sampling and simultaneous multislice (SMS) excitation to rapidly image multiple slices simultaneously. Thus, overcoming the single-slice limitation of standard rtMRI methods. This SMS rtMRI sequence is capable of recording movement at a temporal resolution of up to 37.5ms and spatial resolution of 2.2mm2 in multiple (1-7) locations simultaneously. A compressed sensing image reconstruction pipeline is implemented and is shown to have improved performance, at the cost of increased reconstruction time, compared to standard (gridding and CG-SENSE) reconstruction methods.