A bone scan is a nuclear medicine test. This means that the procedure uses a very small amount of a radioactive substance, called a tracer. The tracer is injected into a vein. There are two parts to a nuclear medicine bone scan. In the first part, you receive an injection into a vein in your arm that usually takes 15–30 minutes. This includes time to explain the procedure and take any 'early' images, if required. In the second part, you return after 1–4 hours to have 'delayed' images taken It's a small amount of radiation. You might have a test scan immediately after the injection. You wait for about 3 hours while the radioactive tracer travels through the blood and collects in your bones. The liquid tends to collect more in areas where the bone is breaking down and repairing itself. A bone scan carries no greater risk than conventional xrays. The tracers in the radioactive substance used in a bone scan produce very little radiation exposure. The risk of having an allergic reaction to the tracers is extremely low. The appointment: First appointment is to have an intravenous injection of a radioisotope tracer. This is done using a small IV cannula which is just in your arm for the first part of the procedure. You will have to lay on the table for this and they will take a series of test scans to compare with the ultimate scan. After that you can go home or anywhere and return for the second part about 4 hours later. Second appointment, you return and get back on the table again. You will be asked to remove any jewellery or other metallic objects. If a bone in your leg is being scanned, then only your legs will be under the scanner. The machine is in two parts: the usual doughnut type and two scanners that are opposite one another that rotate gently around your legs. These are the boxes that say "Siemens" on the side. When these are used, YOU don't move, just these scanners shunt around as indicated by the red arrows. You will be laying feet towards the doughnut scanner (which isn't used). In the monitor above you, there is a stop watch displayed and the entire scan should take about 40-60 minutes. You start off on your back and then are asked to move over on to your side. You might feel stiff and a bit giddy when you're allowed to get up but otherwise, no issues.