Centroid of Fascicular Groups in Micro-CT Image of Peripheral Nerves

Objective: To conduct mathematical expression of the law of internal fascicular groups of peripheral nerves in spatial extension, so as to reveal the universal law of fascicular groups during the process of spatial extension. Methods: The centroid of each fascicular group shown on each Micro-CT image of the peripheral nerves was extracted, and these centroids were connected to form the centroid space curve of each fascicular group respectively based on preliminary studies. Results: The mean value of relative offset of fascicular groups in space was 3.7 mu m while its maximum was: when a distance of 5 mu m was extended, the fascicular groups centroid would have an offset of 21.4 The accuracy of fitting of the centroid spatial curve of the fascicular groups using the 4th-order Fourier model could be up to 98%. Each parameter in the model obeyed the t distribution with position/dimension parameters. The dimension of parameters in the 1st-order component was obviously greater than that of the components of the other orders, indicating that the probability density function of harmonic component parameter showed an obvious peak shape. Conclusions: The centroid space curve of the Fascicular groups could express the extension of fascicular groups in space truly and exactly. The extension process of fascicular groups in space could be expressed accurately by the 4th-order Fourier model. The reason for using the 4th-order model was that a better balance could be obtained in model complexity and accuracy of fitting.