Semi-automated International Cartilage Repair Society scoring of equine articular cartilage lesions in optical coherence tomography images.
BACKGROUND
Arthroscopic optical coherence tomography (OCT) is a promising tool for the detailed evaluation of articular cartilage injuries. However, OCT-based articular cartilage scoring still relies on the operator's visual estimation.


OBJECTIVE
To test the hypothesis that semi-automated International Cartilage Repair Society (ICRS) scoring of chondral lesions seen in OCT images could enhance intra- and interobserver agreement of scoring and its accuracy.


METHODS
Validation study using equine cadaver tissue.


METHODS
Osteochondral samples (n = 99) were prepared from 18 equine metacarpophalangeal joints and imaged using OCT. Custom-made software was developed for semi-automated ICRS scoring of cartilage lesions on OCT images. Scoring was performed visually and semi-automatically by five observers, and levels of inter- and intraobserver agreement were calculated. Subsequently, OCT-based scores were compared with ICRS scores based on light microscopy images of the histological sections of matching locations (n = 82).


RESULTS
When semi-automated scoring of the OCT images was performed by multiple observers, mean levels of intraobserver and interobserver agreement were higher than those achieved with visual OCT scoring (83% vs. 77% and 74% vs. 33%, respectively). Histology-based scores from matching regions of interest agreed better with visual OCT-based scoring than with semi-automated OCT scoring; however, the accuracy of the software was improved by optimising the threshold combinations used to determine the ICRS score.


CONCLUSIONS
Images were obtained from cadavers.


CONCLUSIONS
Semi-automated scoring software improved the reproducibility of ICRS scoring of chondral lesions in OCT images and made scoring less observer-dependent. The image analysis and segmentation techniques adopted in this study warrant further optimisation to achieve better accuracy with semi-automated ICRS scoring. In addition, studies on in vivo applications are required.
Department of Equine Sciences, Utrecht University, Utrecht, the Netherlands.
N C R
NCR
Te Moller
Department of Applied Physics, University of Eastern Finland, Kuopio, Finland.
M
M
Pitkänen
Department of Applied Physics, University of Eastern Finland, Kuopio, Finland.|Diagnostic Imaging Centre, Kuopio University Hospital, Kuopio, Finland.
J K
JK
Sarin
Department of Applied Physics, University of Eastern Finland, Kuopio, Finland.|Diagnostic Imaging Centre, Kuopio University Hospital, Kuopio, Finland.
S
S
Väänänen
Department of Applied Physics, University of Eastern Finland, Kuopio, Finland.
J
J
Liukkonen
Department of Electrical and Computer Engineering, Elizade University, Ondo, Nigeria.
I O
IO
Afara
Department of Applied Physics, University of Eastern Finland, Kuopio, Finland.|Diagnostic Imaging Centre, Kuopio University Hospital, Kuopio, Finland.
P H
PH
Puhakka
Department of Equine Sciences, Utrecht University, Utrecht, the Netherlands.
H
H
Brommer
Department of Equine and Small Animal Medicine, University of Helsinki, Helsinki, Finland.
T
T
Niemelä
Department of Equine and Small Animal Medicine, University of Helsinki, Helsinki, Finland.
R-M
RM
Tulamo
Department of Equine and Small Animal Medicine, University of Helsinki, Helsinki, Finland.
D
D
Argüelles Capilla
Department of Applied Physics, University of Eastern Finland, Kuopio, Finland.|Diagnostic Imaging Centre, Kuopio University Hospital, Kuopio, Finland.
J
J
Töyräs
D000818:Animals; D002357:Cartilage Diseases / Q000473:pathology / Q000662:veterinary*; D002358:Cartilage, Articular / Q000473:pathology*; D006734:Horse Diseases / Q000473:pathology*; D006736:Horses; D015203:Reproducibility of Results; D041623:Tomography, Optical Coherence / Q000379:methods / Q000662:veterinary*
arthroscopy; chondral defect; horse; interobserver agreement