Computational design and fabrication of portable MRI systems

Abstract

In this work, I have developed techniques for designing portable MRI scanners and have applied them to three portable systems for brain imaging. I first describe the procedue for designing a portable, low-field MRI scanner - in particular, how the constraints of compactness and portability affect the design of all system components (magnets, coils, sequences, RF pulses, and reconstruction schemes). I then describe the design of the principal hardware components of a portable MRI system: the B₀ magnet, the magnet shim array, the gradient coils, and the RF coils. This work makes novel use of numerical and computational tools for both sub-system design and physical construction. I next apply this paradigm to the design of gradient coils and a shim magnet array for portable whole-brain MRI scanner and demonstrate in vivo adult brain images. Finally, I describe two novel MRI scanners designed ab ovo using the approach described herein. The former is the "MR Cap", a single-sided MRI device designed for imaging over a reduced 8 x 8 x 3cm³ region of the adult brain; the latter is the "Helmet MRI", a whole-brain scanner optimized specifically for the head geometry.