Exercise-Induced Changes in Knee Cartilage In Vivo: Comparing MRI Sequences.

Area of Science:

• Radiology
• Biomedical Engineering
• Orthopedics

Background:

• Knee osteoarthritis (OA) is a degenerative joint disease characterized by cartilage breakdown.
• Accurate assessment of cartilage changes after loading is crucial for understanding OA progression.
• Current MRI techniques often require multiple sequences, increasing scan time and complexity.

Purpose of the Study:

• To compare a single-sequence quantitative double-echo in steady-state (qDESS) MRI approach with a multi-sequence approach for assessing acute changes in knee cartilage thickness and composition after loading in patients with knee OA.
• To evaluate the agreement between the two MRI acquisition strategies in measuring cartilage changes.

Main Methods:

• Twenty adults with clinical knee OA underwent 3T MRI scans before and immediately after a 25-minute treadmill walk.
• Cartilage thickness and T2 relaxation times were assessed using a single-sequence qDESS and a multi-sequence approach (FSPGR or qDESS combined with MESE).
• Concordant correlation coefficients were used to assess agreement between the methods.

Main Results:

• Strong agreement was observed in pre-activity cartilage thickness measurements between qDESS and FSPGR (CCC 0.842-0.935).
• qDESS detected significant changes in cartilage thickness in the medial femur, lateral tibia, and trochlea after loading.
• qDESS detected T2 changes in all cartilage regions, while multi-sequence approaches detected changes primarily in the patella.

Conclusions:

• The single-sequence qDESS MRI approach demonstrates good agreement with multi-sequence methods for assessing baseline cartilage thickness.
• qDESS is capable of detecting transient changes in knee cartilage thickness and composition following loading in patients with knee OA.
• This suggests qDESS may offer a more efficient method for evaluating acute cartilage responses in knee OA.