Utility of MRI for Characterizing Articular Cartilage Pathology in Dogs with Medial Coronoid Process Disease.

Abstract

OBJECTIVE: To determine whether assessment of morphological MRI sequences or delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) would have strong correlations with arthroscopic assessment of cartilage pathology in dogs with naturally occurring medial compartment pathology of the elbow. METHODS: Dogs tentatively diagnosed with medial coronoid disease had evaluation of their affected elbows using radiography, morphological MRI sequences, and dGEMRIC MRI evaluation prior to arthroscopy. Elbow radiographs were graded 0-6 for severity of changes. Cartilage of the medial coronoid process (MCP) and humeral trochlea (HT) were scored on a 0-3 scale using anatomical MRI sequences. The T1 relaxation times for the MCP and trochlea were quantified using dGEMRIC. Cartilage pathology was graded arthroscopically using a modified Outerbridge score (MOS) by a surgeon blinded to MRI assessment. Correlations between radiography and MOS, and between MRI and MOS, were quantified. RESULTS: Twenty-six elbows in 14 dogs were evaluated. There were statistically significant (&#x2009;<&#x2009;0.05) moderate correlations between radiographic scores and MOS for the MCP (&#x2009;=&#x2009;0.71) and HT (0.57). There was a statistically significant moderate correlation between morphological MRI scoring and MOS for the HT (&#x2009;=&#x2009;0.54;&#x2009;<&#x2009;0.05), but not for the MCP (&#x2009;>&#x2009;0.05). There was a weak, but significant correlation, between the dGEMRIC value and MOS of the MCP (&#x2009;=&#x2009;0.41;&#x2009;<&#x2009;0.05), but no correlation between the dGEMRIC values and MOS for the HT (&#x2009;>&#x2009;0.05). CLINICAL RELEVANCE: Statistically significant correlations to MOS were identified for both radiography and MRI but neither diagnostic modality provided sufficiently strong correlations to serve as a substitute for arthroscopic evaluation of the articular cartilage.