A medical imaging system including a microwave antenna array having a transmitting antenna and a plurality of receiving antennae, wherein the transmitting antenna is configured to transmit microwave signals so as to illuminate a body part of a patient and the receiving antennae are configured to receive the microwave signals following scattering within the body part； a processor configured to process the scattered microwave signals and generate an output indicative of the internal structure of the body part to identify a region of interest within the body part； and a biopsy device comprising a biopsy needle movable relative to the microwave antenna array； wherein the receiving antennae are further configured to receive microwave signals scattered or emitted by the biopsy needle and the processor is further configured to monitor a position of the biopsy needle and to guide the biopsy needle to the identified region of interest within the body part.
