ABSTRACT
Photoacoustic tomography (PAT), based on high-sensitivity optical signals, provides a potentially powerful tool for the laboratory study of inflammatory arthritis by presenting both morphological and physiological characteristics of joint tissues. As PAT is nonionizing, noninvasive, and with an imaging depth in the near-infrared (NIR) region up to several centimeters, enabling penetration of human fingers and toes, the transition from laboratory prototypical device for animals to clinical instrument for humans is very promising. In both two-dimensional (2D) and three-dimensional (3D) imaging of joints, PAT visualizes the relative optical absorption in biological tissues that is contributed by various tissue constituents, including oxy- and deoxy-hemoglobin, lipid, and mineral. A unique feature of PAT is its ability to be readily combined with more established ultrasound imaging technologies. Rat tail joints provide good samples to study the performance of PAT of human finger or toe joints, considering their morphological similarity.
