It takes 24-48 hours for the bone scan contrast agent to decay completely and be excreted from the body. Bone scan is the injection of radioactive contrast agent into the body for a period of time, the contrast agent is redistributed in the body, and the bones are photographed using X-ray to understand the distribution of the contrast agent in the bones, which can be used for the diagnosis of primary tumors, secondary tumors, abnormal bone metabolism and other diseases. After the bone scan, a small amount of radioactive material remains in the patient’s body and it takes 24-48 hours to be completely metabolized and excreted from the body. During this time, pregnant women, children and people who are allergic to the contrast agent should be kept away. Drinking plenty of water can facilitate the excretion of radioactive material. After the bone scan, patients should take rest and avoid overexertion; give light, easy-to-digest food and eat more vitamin-rich vegetables and fruits.