Reflection mode photoacoustic/thermoacoustic dual modality imaging based on hollow concave array

Abstract

Photoacoustic (PA) and thermoacoustic (TA) imaging can share a set of data acquisition and data processing system, in addition to different excitation sources. In this paper, a reflection mode PA/TA dual modality imaging based on a hollow concave array is proposed. The PA/TA signals are excited through the holes in the hollow array by using optical fiber and dipole antenna, respectively. The excited light, microwave and received ultrasonic signals are coaxial, forming a PA/TA dual modality imaging mode. Through the compensation and calibration of the transducer crystal phase and amplitude of the hollow part of the array, a 3-mm-diameter plastic tube filled with 0.9 wt.% salt water, safflower oil, human arm, back of hand and instep are successfully imaged, separately. These experimental results show that the spatial resolution of the PA/TA dual modality imaging system is 0.33 mm, and this technology has a potential to provide the optical and microwave absorption distribution of tissues at the same time by using the same hollow concave array, which is helpful in accurately detecting tumor, diabetic foot and other diseases, and has a wide range of clinical application prospects.