Dr Berg is professor of radiology at the University of Pittsburgh School of Medicine and Magee-Womens Hospital of UPMC and is chief scientific advisor to www.DenseBreast-info.org. Dr Berg led the ACRIN 6666 trial of screening US and MRI in women with dense breasts, led a study of MRI versus positron emission mammography, analyzed the international BE1 study of elastography, and is leading additional prospective trials of US versus tomosynthesis and of contrast-enhanced mammography.