Detecting Articular Cartilage and Meniscus Deformation Effects Using Magnetization Transfer Ultrashort Echo Time...

Area of Science:

• Biomedical Engineering
• Radiology
• Orthopedics

Background:

• Ultrashort echo time (UTE) MRI sequences enhance imaging of musculoskeletal (MSK) tissues with short T2 relaxation times.
• UTE MRI combined with magnetization transfer modeling (UTE-MT) provides robust assessment of MSK tissues.

Purpose of the Study:

• To investigate the variation of UTE-MT measures in tibiofemoral cartilage and meniscus under mechanical loading in cadaveric knee joints.
• To assess the impact of mechanical loading on UTE-MT parameters in young versus elderly knee joints.

Main Methods:

• Fourteen cadaveric knee joints (8 young, 6 elderly) were scanned using UTE-MT sequences at 3-T under three loading conditions (0 N, 300 N, 500 N).
• Macromolecular proton fraction (MMF) was calculated from UTE-MT modeling for various knee regions (meniscus, articular cartilage).
• Statistical analysis (Wilcoxon rank sum test) was performed to compare MRI data between loading conditions and age groups.

Main Results:

• In young donors, MMF increased significantly in the meniscus and loaded articular cartilage regions with increased load (300 N to 500 N).
• MMF decreased significantly in unloaded articular cartilage regions in young donors.
• Elderly donors showed no significant changes in MMF across loading conditions.

Conclusions:

• UTE-MT modeling combined with knee loading can differentiate between normal and potentially abnormal knee joints.
• Tissue deformation effects under load appear more pronounced and uniform in younger knee joints compared to elderly ones.