Abstract: A microwave imaging system and method are disclosed for generating a 3-D map of a body. The system comprises a source of coherent microwave radiation for irradiating the body, at least one microwave detector for detecting at a plurality of locations around the body the amplitude and phase of radiation that has passed through, or has been reflected by, the body, an analyser connected to receive signals from the or each detector and from the source and operative to produce a holographic image indicative at each detection location the phase of the received radiation relative to the phase of radiation received directly from the source at the same location, and a processor for processing the holographic image to calculate in three dimensions the positions of localized physical parameters within the body.