To identify which healthy-looking people are headed toward serious heart disease, most physicians classify patients using standard risk factors. These include high blood pressure, smoking, low HDL ("good") cholesterol, family history of heart disease, diabetes, obesity, and age. But cardiac experts have been searching for more precise diagnostic tools. One potential risk-assessment tool is an imaging study called a coronary calcium computed tomography (CT) scan, which has been around since the late 1980s. "It was initially promoted as an assessment tool for anyone, but without data [to prove its effectiveness]," says Milind Desai, MD, a staff cardiologist at Cleveland Clinic and assistant professor of medicine at Cleveland Clinic Lerner College of Medicine. "Data have emerged in the last few years showing that it has a role for predicting risk for heart disease in rightly selected individuals."