Dual-Frequency Microwave-Induced Thermoacoustic Tomography: An Application in Joint Imaging

The conventional microwave-induced thermoacoustic tomography (TAT) projects the three-dimensional information of a section thickness onto a two-dimensional plane. For joint imaging, the signals of the thin tissue and surrounding bone can be superimposed and projected onto a transducer's scanning plane. Due to the low microwave absorption of the bone, the TAT image of the joint appears dark mottled, resulting in the difficulty of clear and complete reconstruction of some joint tissues. To alleviate this problem, a dual-frequency TAT method was proposed to image the rabbit knee joint and to detect meniscal injury. Compared with the traditional single-frequency TAI images, the corresponding dual-frequency TAI images can more clearly and completely reconstruct various joint tissues and detect joint injury, showing more accurate tissue size and signal trend. Therefore, this method can improve the ability of TAT to image joint tissues, promote the progress of related applications, and also provide a reference for other imaging techniques that are needed to alleviate negative effects of bone.