Abstract: X-ray absorption of breast cancers and surrounding healthy tissue can be very similar, a situation that sometimes leads to missed cancers or false-positive diagnoses. To increase the accuracy of tomosynthesis and cancer diagnosis, dynamic X-ray elastography using a novel pulsed X-ray source synchronized to shear waves generated in a sample is described in the present disclosure. This imaging modality provides both absorption and mechanical properties of the imaged sample. A vibration source is used to vibrate the sample while a synchronously pulsed cold cathode X-ray source images the mechanical deformation. The generated stroboscopic images are further used to derive stiffness maps of the sample in addition to the conventional X-ray image.