Automated segmentation and T2-mapping of the posterior cruciate ligament from MRI of the knee : Data from the osteoarthritis initiative

Segmentation and quantitative tissue evaluation of the posterior cruciate ligament (PCL) from MRI will facilitate analyses into the morphological and biochemical changes associated with various knee injuries and conditions such as osteoarthritis(OA). In this paper, we validate a multi-scale patch-based method for automated segmentation of the PCL from multiecho spin-echo T2-map MRI of the knee acquired from 26 asymptomatic volunteers. Volume, length and T2-relaxation properties of the PCL were then estimated and validation was performed against manual segmentations of the T2-map images. We apply the method to an MR dataset of 88 patients from the osteoarthritis initiative to investigate differences in T2-properties of the PCL between knees at different stages of OA. A mean Dice's similarity coefficient of 74.4±4.2% was obtained for the PCL segmentation. Moderate and strong correlations were noted between automated and manual volume, length and median T2-values (rV=0.67, rL=0.88, rT2=0.78). Wilcoxon rank-sum tests showed no significant differences in length and median T2-values of the PCL between patients at variable stages of knee OA.