Table 4. Significant clusters of MD-related differences between groups and correlations with clinical variables in PVD group.

Test	Cluster Number	Direction of Change	Cluster Size (mL)	COM Position (x, y, z)	Structures
PVD vs. HC	1	Increased	1.037	(27.5, 1, 15.7)	Left putamen, external capsule, superior corona radiata, superior fronto-occipital fasciculus, superior longitudinal fasciculus.
PVD vs. IBS	1	Increased	1.512	(17, 5.9, 0.9)	Left anterior and posterior limb internal capsule, pallidum
Vulvar Pain @ 6 O'clock	1	Positive	6.866	(-32, 53, 13.4)	Right sagittal stratum, posterior thalamic radiation, superior longitudinal fasciculus, splenium corpus callosum, retrolenticular limb internal capsule, tapetum, posterior and superior corona radiata
	2	Positive	2.082	(21.9, 46.9, 47.6)	Posterior and superior corona radiata, superior longitudinal fasciculus Left
	3	Positive	1.013	(29.7, -7.1, 27.4)	Left external capsule, superior corona radiata, superior longitudinal fasciculus
Vaginal Muscle Tenderness Total	1	Positive	3.026	(7.4, 25.2, -8.5)	Left middle and superior cerebellar peduncle, cerebral peduncle Right, cerebral peduncle, thalamus, fornix/stria terminalis, splenium corpus callosum

Statistical tests (both comparisons between groups and correlations with symptom variables) are listed. Clusters reported from largest to smallest. In ‘Direction of Change’, ‘Increased’ and ‘Decreased’ denote higher or lower values in PVD vs other group, respectively, while ‘Positive’ and ‘Negative’ denote increasing or decreasing value with increasing symptom score rating within PVD group only, respectively. Center of Mass (COM) coordinates given for MNI standard space. ‘Structures’ denote overlap of clusters with white matter ROIs from the JHU white matter atlas or subcortical gray matter ROIs from the Harvard-Oxford subcortical atlas, both available through FMRIB Software Library (FSL, https://fsl.fmrib.ox.ac.uk/fsl/fslwiki).

Abbreviations: HC, Healthy Control; IBS, Irritable Bowel Syndrome; PVD, Provoked Vestibulodynia