Table 2.

ADC measures compared by breast density (extremely dense vs. others).

	Extremely Dense (BI-RADS category 4)	Other (BI-RADS categories 1–3)	Mann-Whitney U Test p value
Tumor ADC*	1.59±0.19×10−3 mm2/s	1.60±0.31×10−3 mm2/s	0.89
Normal ADC*	1.95±0.22×10−3 mm2/s	1.97±0.25×10−3 mm2/s	0.73
Tumor ΔADC	13±16%	31±16%	0.032
Normal ΔADC	28±11%	43±12%	0.046
CNR*	2.19±1.77	1.91±1.27	0.55

^*calculated with fat-suppression

Abbreviations: ADC=apparent diffusion coefficient, ΔADC = difference between fat-suppressed and non-fat-suppressed ADC, CNR=contrast-to-noise ratio