Automatic Quantification of Congruity from Knee MRI - Computational Biomechanics for Medicine - page 46

Automatic Quantification of Congruity
from Knee MRI

Sudhakar Tummala, Erik B. Dam, and Mads Nielsen

Abstract Biomechanical factors may play a critical role in the initiation and
progression of Osteoarthritis (OA). We present a method to quantify the medial
tibiofemoral (MTF) congruity from low-field magnetic resonance imaging (MRI).
Firstly, the MTF cartilage compartments were segmented fully automatically using
a voxel quantification approach. Further, the contact area (CA) was computed using
the Euclidian distance transformation by setting the voxel width as threshold.
Eventually, the congruity index (CI) was computed point-by-point over CA as the
inverse distance between the local normal vectors scaled by the local normal
curvatures along the local direction of principal knee motion. The ability of the
CI quantification method was cross-validated for various tasks of diagnosis of OA.
Healthy knees were more congruent than knees with OA. These quantification
methods might be suitable to help explain the onset and diagnosis of OA.

1 Introduction

Musculoskeletal disorders are the most prevalent form of chronic disabilities
worldwide [ 1 ]. They limit the individuals work ability causing pain and limited
range of motion. Osteoarthritis (OA) is the most common type of arthritis, and a

S. Tummala
eScience Center, University of Copenhagen, 2100 Copenhagen, Denmark
e-mail: [e-mail]
E.B. Dam ( * )
BiomedIQ A/S, Copenhagen, Denmark
e-mail: [e-mail]
M. Nielsen
eScience Center, University of Copenhagen, 2100 Copenhagen, Denmark
BiomedIQ A/S, Copenhagen, Denmark