An Objective Computational Method to Quantify Ankle Osteoarthritis From Low-Dose Weightbearing Computed Tomography

Area of Science:

• Radiology
• Orthopedics
• Biomedical Engineering

Background:

• Ankle osteoarthritis (OA) diagnosis relies on subjective radiographic grading with poor reliability.
• Objective quantification of OA is needed for accurate staging and treatment planning.

Purpose of the Study:

• To develop and describe computational methods for objective assessment of ankle OA.
• To quantify radiographic changes on low-dose weightbearing CT (WBCT).

Main Methods:

• Analyzed WBCT scans of ankles with OA and healthy controls.
• Calculated joint space width (JSW) and Hounsfield unit (HU) contrast from image intensity profiles.
• Used 4 projections for detailed quadrant-specific analysis.

Main Results:

• Demonstrated decreased JSW and HU contrast with increasing OA severity (KL grades).
• Average JSW: 3.89 mm (control), 3.06 mm (mild OA), 1.57 mm (severe OA).
• Average HU contrast: 72.31 (control), 62.69 (mild OA), 33.98 (severe OA).

Conclusions:

• A novel methodology for objective, quantitative assessment of ankle OA using JSW and HU contrast was developed.
• This software-based approach offers improved reliability over subjective evaluations.
• Potential to enhance OA classification systems and understanding of OA pathogenesis.