Using two successive pairs of specialized CT scans, a team of Johns Hopkins and Dutch radiologists has produced real-time images of liver tumors dying from direct injection of anticancer drugs into the tumors and their surrounding blood vessels. Within a minute, the images showed whether the targeted chemotherapy did or did not choke off the tumors’ blood supply and saved patients a month of worry about whether the treatment, known as chemoembolization, was working or not, and whether repeat or more powerful treatments were needed.