Module: bundle/stats

Compile statistics on bundle profiles. Uses the data after segmenting the tractogram into different bundles, which in turn are segmented into different sections. This module allows you to perform statistical analysis on bundles using metrics maps. You can choose from several types of statistics. ----------- Available statistics ----------- volume:

  • volume_info: volume, volume_endpoints
  • streamlines_info: streamlines_count, avg_length (in mm or in number of point), average step size, min_length, max_length.
  • shape_info: span, curl, diameter, elongation, surface area, irregularity, end surface area, radius, end surface irregularity, mean_curvature, fractal dimension. ** The diameter, here, is a simple estimation using volume / length.

length: number of streamlines, and mean / min / max / std of :

  • length in number of points
  • length in mm
  • step size.

endpoints: Computes the endpoint map of a bundle. The endpoint map is simply a count of the number of streamlines that start or end in each voxel. Then, Compute the statistics (mean, std) of scalar maps, which can represent diffusion metrics, in endpoint map.

mean std:

  • mean and std for each metric.

streamline count:

  • number of streamlines in a tractogram. (as this information is given by the volume stat you can choose to want only the streamlines count by deactivating volume and activating streamlines count.)

volume per labels:

  • bundle volume per label in mm3. This script supports anisotropic voxels resolution. Volume is estimated by counting the number of voxel occupied by each label and multiplying it by the volume of a single voxel.

mean std per labels:

  • mean and std for each metric along the bundle for each point(labels).

**To create label_map and distance_map, see scil_bundle_label_map.py

Inputs

TypeDescriptionPattern
metamapGroovy Map containing sample information e.g. [ id:'sample1', single_end:false ]
bundlesfileFiber bundle file to compute statistics on.*.trk
labels_mapfilelabel map of the corresponding fiber bundle. this file must have the same dimension than bundle file and have datatype in int. If you have multiple bundes, it must have the same numbers of sections.*.nii.gz
metricsfileNifti file to compute statistics on. Probably some tractometry measure(s) such as FA, MD, RD, … The metrics has to follow a specific naming convention.*{bundle_name}{metric_name}.nii.gz
lesionsfileNifti lesion volume to compute statistics on. The lesion mask must be a binary mask.*.nii.gz

Outputs

TypeDescriptionPattern
metamapGroovy Map containing sample information e.g. [ id:'sample1', single_end:false ]
lengthfileInformation on a tractogram, number of streamlines, mean / min / max / std of length in number of points, length in mm and step size.*__length_stats.json
endpoints_rawfileEstimation of the cortical area affected by the bundle (assuming streamlines start/end in the cortex).*__endpoints_map_raw.json
endpoints_metric_statsfileCompute the statistics of metrics at the bundle endpoint map.*__endpoints_metric_stats.json
mean_stdfileAverage the metric values of all voxels occupied by the bundle.*__mean_std.json
volumefileEvaluate basic measurements of bundle(s).*__volume.json
volume_lesionsfileCompute bundle volume in each lesions in mm3.*__volume_lesion.json
streamline_countfileReturn the number of streamlines in a tractogram.*__streamline_count.json
streamline_count_lesionsfileReturn the number of streamlines in each lesions.*__streamline_count_lesions.json
volume_per_labelsfileCompute bundle volume per label in mm3. This script supports anisotropic voxels resolution. Volume is estimated by counting the number of voxel occupied by each label and multiplying it by the volume of a single voxel.*__volume_per_label.json
volume_per_labels_lesionsfileCompute bundle volume per label in each lesions in mm3.*__volume_per_label_lesions.json
mean_std_per_pointfileAverage the metric values of all voxels occupied by the bundle per label.*__mean_std_per_point.json
lesion_statsfileFile of the lesion-wise volume measure.*_lesion_stats.json
endpoints_headfileEndpoint head map of bundle. The endpoint head map is simply a count of the number of streamlines that start in each voxel.*.nii.gz
endpoints_tailfileEndpoint tail map of bundle. The endpoint tail map is simply a count of the number of streamlines that end in each voxel.*.nii.gz
lesion_mapfileNifti files of labelized lesion(s) map for each bundles.*.nii.gz
versionsfileFile containing software versionsversions.yml

Tools

DescriptionHomepageDOI
scilpyThe Sherbrooke Connectivity Imaging Lab (SCIL) Python dMRI processing toolbox.https://github.com/scilus/scilpy.git

Keywords

Bundle
Labels
Statistic
Volume
Length
Endpoint
Mean std
Streamlines count
json

Authors

@ThoumyreStanislas

Maintainers

@ThoumyreStanislas