(a) Inserting the seed points on different sagittal planes covering the cingulum in order to extract the appropriate ROIs for fiber tracking. (b) Axial views of the automatic segmentation results for the axial cross sections of the cingulum at the processed seed points in superior and inferior parts. (c) Coronal views of the automatic segmentation results for the coronal cross section of the cingulum at the processed seed points in anterior and posterior parts.
The flowchart of the proposed algorithm for extracting ROIs from the initial seed points. tr(.) is the matrix trace and D(r) is the tensor calculated at point r.
Locations of multiple ROIs for the fornix fiber tracking; including three coronal ROIs on the body (labeled by 1, 2, and 3), an axial ROI at the most posterior part (labeled by 4), and a terminating axial ROI at the inferior part (labeled by 5).
The segmentation (top row) and the morphological operation (bottom row) results of the cingulum of a patient pre-RT (left), end-RT (second left), 1-month post-RT (second right), and the shared area between them (right).
The fiber tracking and the segmentation results for one patient with four time samples. The graphs in the middle and the right of the bottom row show the shared, and the majority counted tract between the segmentation results of different time samples, respectively. Note that the majority counted tract is quite smooth, and connected, compared to the shared and the individual segments with some disconnections.
Segmented cingulum, fornix, and corpus callosum of a patient by the proposed methods in different views.
A comparison between the results obtained by our proposed method (right) and the method reported by Wakana (Ref. 14) (left). Note that Wakana's method reconstructed a small number of fibers and thus underestimated the structure cross section. Also, it did not reconstruct the posterior left and right parts.
Comparing percentage changes in the mean FA and MD in end-RT (top) and 1-month post-RT (bottom) with respect to pre-RT in different structures. The numbers 1–5 represent the posterior, superior, and anterior parts of the cingulum, the fornix, and the corpus callosum, respectively. The central marks are the median, the edges of the boxes are the 25th and 75th percentiles, and the whiskers extend to the most extreme data points.
The Dice coefficient of cingulum segments between the test and retest data, the unbiased estimate of within-subject standard deviation (SDw) and the related reproducibility coefficient (RC) for FA and MD in different cingulum segments.
The absolute value of the mean and the estimation standard error for diffusion indices in pre-RT and the percentage changes in the mean, the estimation standard error, and the t-test p-value of the percentage changes in end-RT and 1-month post-RT with respect to pre-RT.
Comparing different structures by t-test p-value on the percentage changes in diffusion indices.
Article metrics loading...
Full text loading...