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Imaging of subchondral bone by optical coherence tomography upon optical clearing of articular cartilage |
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| Authors: | Alexander Bykov Tapio Hautala Matti Kinnunen Alexey Popov Sakari Karhula Simo Saarakkala Miika T Nieminen Valery Tuchin Igor Meglinski |
| Institution: | 1. Optoelectronics and Measurement Techniques Laboratory, University of Oulu, Oulu, Finland;2. ITMO University, Saint‐Petersburg, Russia;3. Interdisciplinary Laboratory of Biophotonics, Tomsk State University, Tomsk, Russia;4. Department of Medical Technology, Institute of Biomedicine, University of Oulu, Oulu, Finland;5. Medical Research Center, University of Oulu and Oulu University Hospital, Oulu, Finland;6. Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland;7. Department of Radiology, University of Oulu, Oulu, Finland;8. Research‐Educational Institute of Optics and Biophotonics, Saratov State University, Saratov, Russia;9. Institute of Precise Mechanics and Control of Russian Academy of Sciences, Russian Academy of Sciences, Saratov, Russia |
| Abstract: | Optical clearing is an effective method to reduce light scattering of biological tissues that provides significant enhancement of light penetration into the biological tissues making non‐invasive diagnosis more feasible. In current report Optical Coherence Tomography (OCT) in conjunction with optical clearing is applied for assessment of deep cartilage layers and cartilage‐bone interface. The solution of Iohexol in water has been used as an optical clearing agent. The cartilage‐bone boundary becomes visible after 15 min of optical clearing that enabling non‐invasive estimation of its roughness: Sa = 10 ± 1 µm. The results show that for 0.9 mm thick cartilage optical clearing is stopped after 50 min with an increase of refractive index from 1.386 ± 0.008 to 1.510 ± 0.009. Current approach enables more reliable detection of arthroscopically inaccessible regions, including cartilage‐bone boundary and subchondral bone, and potentially improves accuracy of the osteoarthritis diagnosis.  |
| Keywords: | Optical Coherence Tomography (OCT) optical clearing articular cartilage subchondral bone osteoarthritis |