An ultrasound scan probe and support mechanism are provided for use in a multi-modality mammography imaging system, such as a combined tomosynthesis and ultrasound imaging system. In one embodiment, the ultrasound components may be positioned and configured so as not to interfere with the tomosynthesis imaging operation, such as to remain out of the X-ray beam path. Further, the ultrasound probe and associated components may be configured to as to move and scan the breast tissue under compression, such as under the compression provided by one or more paddles used in the tomosynthesis imaging operation.