Table 1.

Quantitative overview of the voxels identified by graph clustering, and comparison to segmentation of SWI.

	Minimum	1st Quartile	Median	Mean	3rd Quartile	Maximum
Correlation threshold	0.63	0.72	0.75	0.79	0.88	0.95
Voxels in brain mask	142,800	148,900	154,400	157,600	167,100	172,300
Voxels in clustering mask	10,470	13,600	18,400	17,730	20,940	26,760
Idem, in % of brain mask	6.5%	9.4%	11.1%	11.3%	12.4%	17.9%
Overlap with SWI veins	58.8%	63.7%	68.4%	67.1%	70.8%	72.5 %
Overlap with SWI veins or brain edge	64.5%	72.9%	78.3%	76.6%	79.7 %	87.6%

The minimum, first quartile, median, mean, third quartile, and maximum across all subjects is given for the correlation threshold obtained for the binarization of the correlation matrix to a graph adjacency matrix, the absolute numbers of voxels within the brain mask and within the graph clustering mask, the percentage of voxels of the brain mask that were within the clustering mask, as well as for the percentage of voxels of the graph clustering map that lie within the mask generated from SWI segmentation (which can be interpreted as a measure of specificity), without and with the additional inclusion of brain edge voxels.