The Correlation Between Pennation Angle and the Image Quality of Skeletal Muscle Fiber Tractography Using the Deterministic Diffusion Tensor Imaging

Yoshikazu Okamoto¹, Toru Okamoto², Yuka Kujiraoka²

Fourteen volunteers were scanned using deterministic diffusion tensor imaging (DTI), and six fiber tractographs were constructed from a unilateral calf of each volunteer and the gfiber densityh was calculated in each of the tractographs. The average pennation angle (AVPA) and angle variation (SDPA) were also measured for each muscle by ultrasonography (US) in the same region as the MRI scan. For all eighty-four tractography images, the correlation coefficient between the fiber density and AVPA or SDPA were well correlated (R= 0,715 and -0.472, respectively). Our data suggest that a larger, more variable pennation angle resulted in worse skeletal muscle tractography.