Multispectral Optoacoustic Tomography Enables In Vivo Anatomical and Functional Assessment of Human Tendons

• Published in: Advanced science 2024-05, Vol.11 (18), p.e2308336-n/a
• Main Authors: Ivankovic, Ivana, Lin, Hsiao‐Chun Amy, Özbek, Ali, Orive, Ana, Deán‐Ben, Xosé Luís, Razansky, Daniel
• Format: Article
• Language: English
• Subjects: Adult; Female; Hemoglobin; human tendon imaging; Humans; Injuries; Magnetic resonance imaging; Male; Morphology; multispectral optoacoustic tomography; noninvasive imaging; Photoacoustic Techniques - methods; tendon function; Tendon Injuries - diagnostic imaging; tendon vascularity; Tendons; Tendons - diagnostic imaging; Tomography; Tomography - methods; Ultrasonic imaging; Veins & arteries
• ISSN: 2198-3844; 2198-3844
• DOI: 10.1002/advs.202308336

Tendon injuries resulting from accidents and aging are increasing globally. However, key tendon functional parameters such as microvascularity and oxygen perfusion remain inaccessible via the currently available clinical diagnostic tools, resulting in disagreements on optimal treatment options. Here, a new noninvasive method for anatomical and functional characterization of human tendons based on multispectral optoacoustic tomography (MSOT) is reported. Healthy subjects are investigated using a hand‐held scanner delivering real‐time volumetric images. Tendons in the wrist, ankle, and lower leg are imaged in the near‐infrared optical spectrum to utilize endogenous contrast from Type I collagen. Morphology of the flexor carpi ulnaris, carpi radialis, palmaris longus, and Achilles tendons are reconstructed in full. The functional roles of the flexor digitorium longus, hallicus longus, and the tibialis posterior tendons have been visualized by dynamic tracking during toe extension‐flexion motion. Furthermore, major vessels and microvasculature near the Achilles tendon are localized, and the global increase in oxygen saturation in response to targeted exercise is confirmed by perfusion studies. MSOT is shown to be a versatile tool capable of anatomical and functional tendon assessments. Future studies including abnormal subjects can validate the method as a viable noninvasive clinical tool for tendinopathy management and healing monitoring. Hand‐held multispectral optoacoustic tomography imaging of healthy tendons in human subjects demonstrates the potential for noninvasive, label‐free anatomical visualization and functional motion tracking. Furthermore, various vasculature groups in and around the Achilles tendon can be localized. Blood perfusion studies reveal a diversity of oxygenation dynamics in response to targeted exercise, providing insights into the contentious topic of tendon healing.