Repeatability of DTI-based skeletal muscle fiber tracking
Anneriet M Heemskerk1, Tuhin K Sinha, Kevin J Wilson
1Institute of Imaging Science, Vanderbilt University, Nashville, TN 37232-2310, USA. a.m.heemskerk@vanderbilt.edu
NMR in Biomedicine
|January 26, 2010
Summary
Diffusion tensor imaging (DTI) fiber tracking offers repeatable measurements of muscle architecture, including pennation angle and fiber tract length. This technique is feasible for longitudinal studies tracking muscle changes.
Area of Science:
- Biomedical Engineering
- Musculoskeletal Imaging
- Diffusion Tensor Imaging
Background:
- Diffusion tensor imaging (DTI) allows for muscle fiber tracking to measure architectural parameters like pennation angle (theta) and fiber tract length (L(ft)).
- Limited data exists on the repeatability of these DTI-derived muscle architectural measures and underlying diffusion metrics.
Purpose of the Study:
- To assess the repeatability of DTI fiber tracking for measuring muscle architectural parameters (theta and L(ft)).
- To evaluate the repeatability of the diffusion measures themselves.
Main Methods:
- Four DTI acquisitions were conducted on nine healthy subjects over two days.
- Measurements included eigenvalues and fractional anisotropy at the tibialis anterior muscle's maximum cross-sectional area.
- Fiber tracking was performed to calculate theta and L(ft).
Main Results:
- The highest repeatability for both DTI indices and architectural parameters was observed between acquisitions.
- Interclass correlation coefficients (ICC) for theta and L(ft) were > 0.6.
- Repeatability coefficients were < 10.2 degrees for theta and < 50 mm for L(ft).
Conclusions:
- DTI-based fiber tracking demonstrates very good repeatability for diffusion measures and acceptable repeatability for architectural measurements (theta and L(ft)).
- This validates the feasibility of using DTI fiber tracking for longitudinal studies investigating muscle architecture alterations.
