Standard "millimeter-wave" or "backscatter" body scanners used for general security are primarily designed to detect objects hidden under clothing, not items inside the body. However, if security has a specific suspicion that someone is a "drug mule," they can utilize full-body X-ray machines (often called body cavity scanners) or refer the person to a hospital for a medical X-ray. These medical-grade scans can clearly detect foreign packages, pellets, or balloons swallowed or inserted into the body. While the general TSA-style scanners see organic materials as a colored blur on a monitor, they are not high-resolution enough to peer through skin and bone; thus, specialized, higher-radiation equipment or physical signs are required for internal detection.