Abstract: Systems and methods are provided for CT-based elastography. A CT gantry is rotated while acquiring CT image data at a first frequency while tissue vibration is induced at a second vibrational frequency. The data acquisition frequency and the vibrational frequency are harmonically related and are synchronized such that the vibrational period aligns with the data acquisition period. Displacement of each of a plurality of tissue points are calculated in each of a series of images and a displacement map is generated demonstrating relative tissue stiffness.