 What is this lesion acting like? Is it soft? Is it hard? Does it transmit sound quickly or does it not? And as a result of that, it can decrease the number of unnecessary breast biopsies. Ultrasound in the past has helped doctors find roughly twice the number of invasive cancers in dense breasts than with mammograms alone. But it wasn't good at differentiating which lesions were benign, like scars from cosmetic or medical surgeries.