Molecular imaging (formerly nuclear medicine) is a branch of medical imaging that uses small amounts of radioactive material to diagnose or treat a variety of diseases, including many types of cancers, heart disease and certain other abnormalities within the body.
Molecular imaging or radionuclide imaging procedures are noninvasive and usually painless medical tests that help physicians diagnose medical conditions. These imaging scans use radioactive materials called radiopharmaceuticals or radiotracers.
Depending on the type of molecular imaging exam you are undergoing, the radiotracer is either injected into a vein, swallowed or inhaled as a gas and eventually accumulates in the organ or area of your body being examined, where it gives off energy in the form of gamma rays. This energy is detected by a device called a gamma camera, a (positron emission tomography) PET scanner and/or probe.
These devices work together with a computer to measure the amount of radiotracer absorbed by your body and to produce special pictures offering details on both the structure and function of organs and tissues.
Molecular imaging also offers therapeutic procedures such as radioactive iodine (I-131) therapy that uses radioactive material to treat cancer and other medical conditions affecting the thyroid gland.
Why is this procedure conducted?
Physicians use radionuclide imaging procedures to visualize the structure and function of an organ, tissue, bone or system of the body.
Molecular imaging scans are performed to:
- Analyze kidney function
- Visualize heart blood flow and function (such as a myocardial perfusion scan)
- Scan lungs for respiratory and blood flow problems
- Identify inflammation in the gallbladder
- Evaluate bones for fractures, infection, arthritis and tumors
- Determine the presence or spread of cancer in various parts of the body
- Identify bleeding into the bowel
- Locate the presence of infection
- Measure thyroid function to detect an overactive or underactive thyroid
- Investigate abnormalities in the brain, such as seizures, memory loss and abnormalities in blood flow
- Localize the lymph nodes before surgery in patients with breast cancer or melanoma
Molecular imaging therapies include:
- Radioactive iodine (I-131) therapy used to treat hyperthyroidism (overactive thyroid gland, for example, Graves' disease) and thyroid cancer
- Radioactive antibodies used to treat certain forms of lymphoma (cancer of the lymphatic system)
- Radioactive phosphorus (P-32) used to treat certain blood disorders
- Radioactive materials used to treat painful tumor metastases to the bones
How do I prepare for the exam?
You may be asked to wear a gown during the exam or you may be allowed to wear your own clothing.
Women should always inform their physician or technologist if there is any possibility that they are pregnant or if they are breastfeeding their baby.
You should inform your physician and the technologist performing your exam of any medications you are taking, including vitamins and herbal supplements. You should also inform them if you have any allergies and about recent illnesses or other medical conditions.
Jewelry and other metallic accessories should be left at home if possible, or removed prior to the exam because they may interfere with the procedure.
You will receive specific instructions based on the type of scan you are undergoing. For more information, please read about your scheduled procedure using the links on the left.