By making body tissues "dance" to sound, two University of Rochester scientists have developed a new variation of diagnostic ultrasound that could help doctors find cancer tumors of the prostate, breast, liver and spleen they might otherwise miss.

Their method, adapted from a technology used in police radar guns, distinguishes between hardness and softness of tissue. This is important in cancer diagnosis since most malignant tumors are hard while most healthy tissue is soft. Ultrasound alone doesn't always "see" these differences."We use sound to jiggle the tissue and ultrasound to see the motion," said Robert Lerner, who invented the Doppler-vibration imaging technique along with Kevin Parker.