This note presents a superconducting joint technique for the development of MgB magnetic resonance imaging (MRI) magnets. The MgB superconducting joint was fabricated by a powder processing method using Mg and B powders to establish a wire-bulk-wire connection. The joint resistance measured using a field-decay method was <10 Ω, demonstrating that the proposed joint technique could be employed for developing "next-generation" MgB MRI magnets operating in the persistent current mode.