We investigate the use of ultrasound images as prior structural information (also known as ultrasound spatial priors) to guide microwave breast imaging so as to enhance its achievable complex permittivity images. In the main approach considered herein, the edges within the discretized
ultrasound compressibility image are fed as spatial priors
into a microwave imaging algorithm. It is shown that this
method requires minimal post-processing of the ultrasound
image and can enhance the achievable microwave image
accuracy. It is also demonstrated that small tumours can
still go undetected in microwave breast imaging using this
method if their edges are missing from the spatial priors.