How much radiation is in a nuclear medicine scan?

Very small quantities are used for imaging scans. Nuclear medicine imaging uses small amounts of radioactive drugs and images of how those drugs move around the body. This helps doctors see how the body works. In contrast, x-rays or CT scans show what your body looks like (that is, early diagnosis is often possible with nuclear medicine, since changes in function often occur before changes in the Unlike computed tomography or x-ray devices, nuclear medicine imaging devices do not emit radiation.

The nuclear medicine pharmaceuticals used emit “gamma rays” that allow tracking the progress of radioactive pharmaceuticals within the body. Keep in mind that the radioactive material used disappears (breaks down) in a short time. If a procedure offers useful information that is likely to help your doctor decide your treatment, the benefits of nuclear medicine imaging will outweigh your small potential risk. While there is no direct evidence that the low amount of radiation used in nuclear medicine produces such effects, it is prudent to assume that every exposure to ionizing radiation carries some risk.

Nuclear medicine scans are especially useful for cancer because they show tumors and track whether they spread within the body. A nuclear medicine scan uses small amounts of radiation to create images of tissues, bones, and organs inside the body. At this time, there is no formal mechanism to record and track a patient's cumulative radiation exposure, as is the case with staff. A radiologist or doctor specializing in nuclear medicine interprets the images and sends a report to the doctor.

But if there is any reason to believe that an x-ray, CT scan, or nuclear medicine scan (such as positron emission tomography) is the best way to detect cancer or other diseases, the person will most likely receive more help than the small dose of radiation can harm. The steps needed to prepare for a nuclear medicine scan depend on the type of test and the tissue being studied. Nuclear medicine scans (also known as nuclear imaging, radionuclide imaging, and nuclear scans) can help doctors find tumors and see how much cancer has spread in the body (called the cancer stage). Even so, be sure to tell your doctor about any allergies and if you have had problems with nuclear medicine scans in the past.

The amount of radiation exposure from an imaging test depends on the imaging test being used and the part of the body being tested. In general, the amount of radiation from nuclear medicine procedures is similar to that of other radiological procedures and natural background radiation. However, the doctor will need more focused images (x-rays, CT scans, MRI) of those areas and look for smaller tumors that may not appear on the nuclear scan.