Please use this identifier to cite or link to this item: http://hdl.handle.net/10397/2524
Title: Effects of optical beam angle on quantitative optical coherence tomography (OCT) in normal and surface degenerated bovine articular cartilage
Authors: Huang, Yan-Ping
Saarakkala, Simo
Toyras, Juha
Wang, Li-Ke
Jurvelin, Jukka S.
Zheng, Yong-Ping
Subjects: Optics, quantum optics and lasers
Biological physics
Medical physics
Issue Date: 21-Jan-2011
Publisher: IOP Publishing
Source: Physics in medicine and biology, 21 Jan. 2011, v. 56, no. 2, p. 491-509.
Abstract: Quantitative measurement of articular cartilage using optical coherence tomography (OCT) is a potential approach for diagnosing the early degeneration of cartilage and assessing the quality of its repair. However, a non-perpendicular angle of the incident optical beam with respect to the tissue surface may cause uncertainty to the quantitative analysis, and therefore, significantly affect the reliability of measurement. This non-perpendicularity was systematically investigated in the current study using bovine articular cartilage with and without mechanical degradation. Ten fresh osteochondral disks were quantitatively measured before and after artificially induced surface degradation by mechanical grinding. The following quantitative OCT parameters were determined with a precise control of the surface inclination up to an angle of 10° using a step of 2°: optical reflection coefficient (ORC), variation of surface reflection (VSR) along the surface profile, optical roughness index (ORI) and optical backscattering (OBS). It was found that non-perpendicularity caused systematic changes to all of the parameters. ORC was the most sensitive and OBS the most insensitive to the inclination angle. At the optimal perpendicular angle, all parameters could detect significant changes after surface degradation (p < 0.01), except OBS (p > 0.05). Nonsignificant change of OBS after surface degradation was expected since OBS reflected properties of the internal cartilage tissue and was not affected by the superficial mechanical degradation. As a conclusion, quantitative OCT parameters are diagnostically potential for characterizing the cartilage degeneration. However, efforts through a better controlled operation or corrections based on computational compensation mechanism should be made to minimize the effects of non-perpendicularity of the incident optical beam when clinical use of quantitative OCT is considered for assessing the articular cartilage.
Rights: © 2011 Institute of Physics and Engineering in Medicine. The online abstract of the journal is located at: http://iopscience.iop.org/0031-9155/56/2/013
Type: Journal/Magazine Article
URI: http://hdl.handle.net/10397/2524
DOI: 10.1088/0031-9155/56/2/013
ISSN: 0031-9155
Appears in Collections:HTI Journal/Magazine Articles

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