Author/Authors :
PUHAKKA, Pia H Department of Applied Physics - University of Eastern Finland, Kuopio , MOLLER, Nikae C R te Department of Equine Sciences - Utrecht University, Utrecht, the Netherlands , TANSKA, Petri Department of Applied Physics - University of Eastern Finland, Kuopio , SAARAKKALA, Simo Department of Applied Physics - University of Eastern Finland, Kuopio , TIITU, Virpi School of Medicine - Institute of Biomedicine, Anatomy - University of Eastern Finland, Kuopio; , KORHONEN, Rami K Department of Applied Physics - University of Eastern Finland, Kuopio , BROMMER, Harold Department of Equine Sciences - Utrecht University, Utrecht, the Netherlands , VIRÉN, Tuomas Cancer Center - Kuopio University Hospital, Kuopio, Finland , JURVELIN, Jukka S Department of Applied Physics - University of Eastern Finland, Kuopio , TÖYRÄS, Juha Department of Applied Physics - University of Eastern Finland, Kuopio
Abstract :
Background and purpose — Arthroscopic estimation of articular
cartilage thickness is important for scoring of lesion severity, and
measurement of cartilage speed of sound (SOS)—a sensitive index
of changes in cartilage composition. We investigated the accuracy
of optical coherence tomography (OCT) in measurements of car-
tilage thickness and determined SOS by combining OCT thick-
ness and ultrasound (US) time-of-fl ight (TOF) measurements.
Material and methods — Cartilage thickness measurements
from OCT and microscopy images of 94 equine osteochondral
samples were compared. Then, SOS in cartilage was determined
using simultaneous OCT thickness and US TOF measurements.
SOS was then compared with the compositional, structural, and
mechanical properties of cartilage.
Results — Measurements of non-calcifi ed cartilage thickness
using OCT and microscopy were signifi cantly correlated (ρ = 0.92;
p < 0.001). With calcifi ed cartilage included, the correlation was
ρ = 0.85 (p < 0.001). The mean cartilage SOS (1,636 m/s) was in
agreement with the literature. However, SOS and the other prop-
erties of cartilage lacked any statistically signifi cant correlation.
Interpretation — OCT can give an accurate measurement of
articular cartilage thickness. Although SOS measurements lacked
accuracy in thin equine cartilage, the concept of SOS measure-
ment using OCT appears promising.
