Abstract: A novel, integrated dual-modal breast imaging system that requires minimal or no movement of the breast between scans. A static receptacle holds the breast or other target object still. An acoustic imaging fixture with acoustic transducers, and an electromagnetic imaging chamber with electromagnetic antennae, each perform imaging of the target object when occupying a respective working position of surrounding relationship to the receptacle, and at least one thereof is movable relative to said static receptacle into and out of the respective working position, without repositioning of the static receptacle. Acoustic imaging is performed, and prior information extracted from the sound-speed image is incorporated into the electromagnetic inversion algorithm, whereby low-resolution sound-speed reconstructions are used to improve tumour detection via electromagnetic imaging.