Quantifying the Fascicular Changes in Recovered Achilles Tendon Patients Using Diffusion Magnetic Resonance Imaging...

Area of Science:

• Orthopedics
• Musculoskeletal imaging
• Biomedical engineering

Background:

• Achilles tendon rupture (ATR) often leads to persistent calf muscle deficits, impacting long-term recovery.
• Current research primarily focuses on morphological changes, neglecting crucial fascicular alterations within muscles.
• Diffusion tensor imaging (DTI) offers advanced insights into tissue microstructure and properties.

Purpose of the Study:

• To investigate fascicular changes in the soleus muscle of ATR patients post-recovery using DTI.
• To compare DTI-derived indices and fiber tractography between injured and healthy legs.
• To establish DTI's feasibility in quantifying microstructural alterations after ATR.

Main Methods:

• Employed DTI to derive mean diffusivity (MD), fractional anisotropy (FA), and eigenvalues (λ1, λ2, λ3).
• Utilized fiber tractography to analyze fascicular structure and fiber length distribution.
• Compared DTI parameters and tractography findings between the injured and healthy legs of ATR patients.

Main Results:

• Standard deviations of FA, MD, and eigenvalues in the soleus muscle were more sensitive predictors of ATR-related changes than volumetric region of interest (ROI) comparisons.
• Fiber tractography revealed smaller fascicular tracts in the injured leg compared to the healthy leg in 80% of participants.
• DTI and fiber tractography successfully quantified fascicular changes in recovered ATR patients.

Conclusions:

• DTI-derived indices, particularly their standard deviations, effectively predict soleus muscle changes post-ATR.
• Fiber tractography demonstrates reduced fascicular size in injured limbs, indicating persistent microstructural alterations.
• DTI and fiber tractography are feasible and valuable tools for assessing fascicular changes following Achilles tendon rupture.