A white blood cell scan is performed across two sessions. A technician will take a blood sample from you. Your white blood cells are then linked to indium, a radioactive substance (takes about 2-3 hours). Following this, your blood will be re-injected into you via a vein in your arm. This procedure is called autologous transfusion. The radioactivity of your blood cells is measured with a scanner. The first session takes place about 24 hours after you were injected with the indium. The second session takes place between 7 and 14 days later. The first session is done as a whole body scan while the second one is focused on the lungs. Indium has been used in nuclear medicine since 1958. It is also known as radium 223 or radium X. The element was originally discovered by Frédéric Joliot in 1911. It is obtained from uranium ore. Indium is used in small quantities in most nuclear facilities because it can be used as a tracer for research or treatment purposes. It is also found in some consumer products such as fluorescent lights, metal alloys, and computer chips. In conclusion, a white blood cell scan is used to look at the activity of your immune system. Cancer cells produce antibodies too. Thus, detecting these antibodies can help diagnose cancer. Further, scans using this method have helped doctors find tumors that may not be apparent otherwise.