It was well after midnight when Salvatore J. A. Sclafani, MD, finally hit the "send" button. Soon, colleagues would awake to his e-mail, expressing his anguish and shame over the discovery that the tiniest, most vulnerable of all patients — premature babies — had been over-radiated in the department he ran at State University of New York Downstate Medical Center in Brooklyn. A day earlier, Dr. Sclafani noticed that a newborn had been irradiated from head to toe — with no gonadal shielding — even though only a simple chest X-ray had been ordered. "I was mortified," he wrote on July 27, 2007. Worse, technologists had given the same baby about 10 of these whole-body X-rays. "Full, unabashed, total irradiation of a neonate," Dr. Sclafani said, adding, "This poor, defenseless baby."