Inter-subject comparison of MRI knee cartilage thickness

Abstract

In this paper, we present the development and application of current image processing techniques to perform MRI inter-subject comparison of knee cartilage thickness based on the registration of bone structures. Each point in the bone surface which is part of the bone-cartilage interface is assigned a cartilage thickness value. Cartilage and corresponding bone structures are segmented and their shapes interpolated to create isotropic voxels. Cartilage thicknesses are computed for each point in the bone-cartilage interfaces and transferred to the bone surfaces. Corresponding anatomic points are then computed for bone surfaces based on shape matching using 3D shape descriptors called shape contexts to register bones with affine and elastic transformations, and then perform a point to point comparison of cartilage thickness values. An alternative technique for cartilage shape interpolation using a morphing technique is also presented. The cartilage segmentation and morphing were validated visually, based on volumetric measurements of porcine knee images which cartilage volumes were measured using a water displacement method, and based on digital thickness values computed with an established technique. Shape matching using 3D shape contexts was validated visually and against manual shape matching performed by a radiologist. The reproducibility of intra- and inter-subject cartilage thickness comparisons was established, as well as the feasibility of using the proposed technique to build a mean femoral shape, cartilage thickness map, and cartilage coverage map. Results showed that the proposed technique is robust, accurate, and reproducible to perform point to point inter-subject comparison of knee cartilage thickness values.

Are There Sex Differences in Knee Cartilage Composition and Walking Mechanics in Healthy and Osteoarthritis Populations?

“…Medial femoral condyle (MF), medial tibia (MT), lateral femoral condyle (LF), lateral tibia (LT), patella (P), Trochlea (TrF), medial meniscus, and lateral meniscus cartilage compartments were segmented semiautomatically (automated edge detection and manual correction) on multiple slices using in-house software program developed with Matlab (Mathworks, Natick, MA, USA) based on edge detection and Bezier splines [6]. T 1q relaxation time maps were constructed by two-parameter fitting of the image intensity (voxel-by-voxel) for four T 1q -weighted images using a Levenberg-Marquardt monoexponential fitting algorithm developed in-house: S(TSL) = S 0 exp(ÀTSL/T 1q ), where TSL is the spin lock time and S 0 is the signal intensity when TSL = 0 ms; S(TE) = S 0 exp(ÀTE/T 2 ).…”

In vivo tibiofemoral cartilage‐to‐cartilage contact area of females with medial osteoarthritis under acute loading using MRI

“…To measure tibiofemoral contact area, the area of the femoral cartilage and the tibial cartilage in contact was visually inspected and semiautomatically segmented using Bezier-splines implemented with software developed in MatLab (MathWorks, Natick, MA) (24). During segmentation the evaluator was blinded to KL status and loading conditions.…”

An Atlas-Based Approach to Study Morphological Differences in Human Femoral Cartilage Between Subjects from Incidence and Progression Cohorts: MRI Data from Osteoarthritis Initiative

“…Extending the previous work of Cohen et al and Carballido-Gamio et al (Cohen et al, 2003;Carballido-Gamio et al, 2008), the focus of this study was to create a femoral cartilage atlas from high-resolution 3D MR images made available by the OAI through version 0.A.1. The atlas-based approach to study localized morphological changes has been well established for brain and we extend this to study localized changes in cartilage morphology in osteoarthritis.…”

“…Cohen et al generated templates of cartilage of the patellofemoral joint and demonstrated the potential of using the standard thickness maps by comparing it with thickness maps generated for individual patients to identify regions with maximum loss of cartilage in patients with Osteoarthritis (Cohen et al, 2003). Recently, Carballido-Gamio et al performed inter-subject comparison of knee cartilage thickness after registration to a common reference space (Carballido-Gamio et al, 2008). They measured the thickness at each point on the bone-cartilage interface and used affine and elastic registration techniques for point-wise comparison of cartilage thickness.…”