A heating system including a submersible aquarium heater, an air vortex heater, and a thermostat was employed to achieve an ambient temperature of approximately 36◦C, to keep the mouse from losing body
temperature during anesthesia. After the in vivo imaging with hfMAT-MI, the 64-channel ultrasound system was used to conduct SA scans for the mouse in the plastic holder at a series of layers with increments of 1.5 mm along the z direction,i.e.,z=1.5 mm. Then, the mouse was taken out from the plastic holder, wiped dry and placed on a heater pad.