Investigation of Inward-Outward Ring Permanent Magnet Array for Portable Magnetic Resonance Imaging (MRI)

TL;DR

This paper explores the design, properties, and feasibility of Inward-Outward ring (IO ring) permanent magnet arrays for portable MRI, highlighting their advantages over traditional Halbach arrays in generating homogeneous, longitudinal magnetic fields.

Contribution

It provides a comprehensive analysis of IO ring arrays, compares them with Halbach arrays, and demonstrates their practical feasibility for portable MRI applications.

Findings

IO ring arrays can produce high, homogeneous longitudinal magnetic fields.

They offer flexible design options for different MRI applications.

Feasibility of constructing IO ring arrays in a lab setting is confirmed.

Abstract

Permanent magnet array (PMA) is a popular option to provide the main magnetic field in a dedicated portable magnetic resonance imaging (MRI) system because it does not need power or a cooling system and has a much stronger field strength compared to a resistive magnet. Aside from the popular Halbach array that has a transversal field direction, the Inward-Outward ring (IO ring) array is a promising candidate that offers a longitudinal field direction with various design and engineering possibilities. In this article, a thorough study of IO ring arrays is conducted by examining the relation between the design parameters and its field patterns, its variants that lead to different applications and their properties. A detailed comparison between an IO ring array and Halbach array was conducted and reported. Moreover, the feasibility of building an IO ring array in a lab is demonstrated. The investigations strongly indicate that IO ring is a promising candidate that can offer high and homogeneous fields or a desired field pattern to portable MRI systems. With a longitudinal field direction, an IO ring array opens up opportunities to adopt MRI advanced technology and techniques in a portable system to improve image quality and shorten scan time.