Table 4.

Correlations of Mammographic Subregion Density Measures with UST Density Measures

	Mammographic Dense Area (cm2)	Mammographic Non- Dense Area (cm2)	Total Mammographic Breast Area (cm2)
K-Means Mean Dense Sound Speed (m/s)	0.367	−0.323	−0.194 (0.012)
K-Means Mean Non-Dense Sound Speed (m/s)	0.584	−0.381	−0.212 (0.006)
K-Means Dense Volume (cm3)	0.198 (0.011)	0.408	0.501
K-Means Non-Dense Volume (cm3)	−0.168 (0.031)	0.764	0.764
K-Means Percent Density (%)	0.412	−0.542	−0.451
Threshold Mean Dense Sound Speed (m/s)	0.178 (0.022)	−0.277	−0.196 (0.012)
Threshold Mean Non-Dense Sound Speed (m/s)	0.579	−0.292	−0.135 (0.084)
Threshold Dense Volume (cm3)	0.466	0.153 (0.050)	0.326
Threshold Non-Dense Volume (cm3)	−0.233	0.780	0.748
Threshold Percent Density (%)	0.569	−0.577	−0.428
Total Breast Volume (cm3)	−0.082 (0.296)	0.720	0.745

Each cell contains Spearman correlation coefficient with p-value shown in brackets. For entries without bracket, p-value was p < 0.001.