Photoacoustic tomography for human musculoskeletal imaging and inflammatory arthritis detection.

With the capability of assessing high resolution optical contrast in soft tissues, photoacoustic imaging (PAI) can offer valuable structural and functional information of human joints, and hold potential for diagnosis and treatment monitoring of inflammatory arthritis. Recent studies have demonstrated that PAI can map 2D and 3D morphology of the cartilage, synovium, vascularity, and bone tissue in human peripheral joints. Initial trials with patients affected by inflammatory arthritis have also suggested that PAI can detect the hemodynamic properties in articular tissues as well as their changes due to active inflammation. This review focuses on the recent progress in technical development of PAI for human musculoskeletal imaging and inflammation detection. PAI can provide non-invasive and non-ionizing serial measurements for monitoring of therapeutic interventions with the potential for higher sensitivity than existing imaging modalities such as ultrasound. However, further investigation is needed to validate the value of PAI in rheumatology clinical settings.