A magnet assembly for a portable magnetic resonance imaging (MRI) system includes a former having a plurality of slots and a plurality of magnet blocks configured to create a single-sided permanent magnet. Each of the plurality of magnet blocks are positioned in one of the plurality of slots of the former. The arrangement of the plurality of magnet blocks is configured to optimize homogeneity over a target field of view for brain imaging and to form a cap-shaped configuration to be positioned on a head of a subject.
