Automated techniques for visualization and mapping of articular cartilage in MR images of the osteoarthritic knee: a base technique for the assessment of microdamage and submicro damage

Abstract

The purpose of this paper is to describe automated techniques for the visualization and mapping of articular cartilage in magnetic resonance (MR) images of the osteoarthritic knee. The MR sequences and analysis software which will be described allow the assessment of cartilage damage using a range of standard scanners. With high field strength systems it would be possible, using these techniques, to assess micro-damage. The specific aim of the paper is to develop and validate software for automated segmentation and thickness mapping of articular cartilage from three-dimensional (3-D) gradient-echo MR images of the knee. The method can also be used for MR-based assessment of tissue engineered grafts. Typical values of cartilage thickness over seven defined regions can be obtained in patients with osteoarthritis (OA) and control subjects without OA. Three groups of patients were studied. The first group comprised patients with moderate OA in the age range 45-73 years. The second group comprised asymptomatic volunteers of 50-65 years; the third group, younger volunteers selected by clinical interview, history and X-ray. In this paper, sagittal 3-D spoiled-gradient steady-state acquisition images were obtained using a 1.5-T GE whole-body scanner with a specialist knee coil. For validation bovine and porcine cadaveric knees were given artificial cartilage lesions and then imaged. The animal validations showed close agreement between direct lesion measurements and those obtained from the MR images. The feasibility of semi-automated segmentation is demonstrated. Regional cartilage thickness values are seen as having practical application for fully automated detection of OA lesions even down to the submicrometer level.

Knee osteoarthritis detection based on the combination of empirical mode decomposition and wavelet analysis

“…On the other hand, the MRI technology can be susceptible to the defection of the articular cartilage surface and soft tissue. The cartilage MRI diagnosis remains dependent on visual assessments, so there is a risk that small early OA lesions may not be detected (Cashman, Kitney, Gariba, & Carter, 2002). Further, arthroscopy is a rod-shaped optical instrument with a diameter of about 5 mm for observing the internal structure of joints.…”

Identification of Knee Cartilage Changing Pattern

“…Some basic strategies include restricting assessments to partial regions of the cartilage or segmenting alternate MR slices [8][9][10]. To automate the procedure of cartilage segmentation for MR images, computer-aided algorithms based on B-splines and active contour models have been utilized [8,9,[11][12][13]. However, these approaches were not accurate enough to be used in clinical research, especially in detecting small cartilage changes [10].…”

Sensitivity of Standing Radiographs to Detect Knee Arthritis: A Systematic Review of Level I Studies

“…Screening tools have been used to identify structural signs of knee osteoarthritis. Numerous studies [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] have examined a range of imaging modalities from radiography to magnetic resonance imaging as screening tools for osteoarthritis. These studies found that the ability to detect structural changes of the articular cartilage in the knee consistent with osteoarthritis is difficult.…”