Nuclear Medicine

Advanced metabolic imaging in San Diego

Nuclear medicine technologies specialize in the imaging of an organ’s metabolic functions. This helps doctors diagnose certain diseases and identify various medical conditions.


During a nuclear medicine procedure, an intravenous (IV) catheter is usually inserted into a vein in your arm or hand. Through this IV, a radioactive tracer is injected. A special camera called a gamma camera photographs the organ or body part. The resulting film shows normal absorption or dark and light spots, relative to how the organ is functioning. A PET scan is a common type of nuclear medicine.


Nuclear medicine imaging can evaluate a wide range of conditions and is often used to:


  • Evaluate kidney function
  • Measure thyroid function
  • Visualize blood flow to the heart
  • Scan lungs for respiratory and blood flow problems
  • Identify inflammation in the gallbladder
  • Evaluate bones for fractures and infections
  • Determine whether cancer is present or has spread in certain parts of the body
  • Investigate conditions that involve the brain, such as seizures or memory loss

Types of nuclear medicine tests

Nuclear medicine can localize cancer in the bone, identify blood clots in the lungs and scan the gallbladder and other organs for abnormalities. Learn more about common types of nuclear medicine tests below.

A thyroid scan is used to gather information about the structure and function of the thyroid. The procedure uses a radioactive tracer and a special camera to measure how much of the tracer is absorbed from the bloodstream by the thyroid gland.


A thyroid scan can show the size, shape and location of the thyroid gland. The test can also locate spots in the thyroid gland that are overactive or underactive. The camera takes pictures of the thyroid gland from three different angles.


Thyroid scans are used to:


  • Determine if the gland is working properly
  • Diagnose problems, such as an overactive thyroid gland
  • Assess the nature of a nodule discovered in the gland
  • Detect areas of abnormality, such as lumps or inflammation
  • Determine whether thyroid cancer has spread beyond the thyroid gland
  • Evaluate changes in the gland following surgery, radiotherapy or chemotherapy


In performing a thyroid test, a radiotracer is usually administered 30 minutes before the test begins. The radioactivity of this tracer is very low, and there are no side effects. The test may be performed over a two-day period, or completed in one 60-minute appointment depending on how your doctor ordered the test.

A bone scan is used to evaluate damage to the bones or to monitor conditions that affect the bones, such as trauma and infection. Bone scans can often detect problems well in advance of regular X-ray scans.


A nuclear medicine bone scan is not the same as a bone density test, which is used to detect osteoporosis and bone loss.


In a bone scan, a radioactive tracer is injected into the arm. The tracer travels through the bloodstream and into the bones. A special camera takes pictures to show cell activity and function in the bones. Areas that absorb little or no amount of tracer appear as dark or “cold” spots, which might indicate a lack of blood supply to the bone or the presence of certain types of cancer. Areas of rapid bone growth absorb increased amounts of the tracer and show up as bright spots in the pictures, possibly indicating the presence of a tumor, a fracture or an infection.


Bone scans are prescribed to:


  • Determine whether cancer from another area has spread to the bone
  • Help determine the cause or location of unexplained bone pain, such as chronic lower back pain
  • Identify arthritis or osteoporosis
  • Diagnose broken bones, such as a hip fracture or stress fracture
  • Detect damage to the bones caused by infection or other conditions


The radioactivity of the tracer used in a bone scan is very low, and there are no side effects. The scan is performed two to three hours after the injection of the radioactive tracer.

Also called a nuclear stress test, myocardial perfusion imaging is used to evaluate blood flow through the coronary arteries to the heart. These tests can help determine if a person has coronary artery disease.


Someone with mild or moderate coronary artery disease might not experience any symptoms during normal activities. If that person becomes physically or emotionally stressed, however, the heart might demand more blood than the arteries are able to supply. This state can lead to chest pain, shortness of breath and other symptoms.


Myocardial perfusion stress tests consist of a rest and exercise portion. Images of the heart at rest are captured first by injecting a tracer and completing the first set of images in approximately 30 minutes.


Next, exercise is performed on a treadmill or a drug is injected that simulates the effects of exercise. Once the heart reaches a certain level, a second tracer is administered, and after allowing 15 to 30 minutes for circulation, a second set of images is captured. The entire test can take up to three hours to complete.

A gallbladder scan is used to evaluate gallbladder function. This scan can locate blockages in the tubes that lead from the liver to the gallbladder and small intestine.


This procedure involves the injection of a small amount of radioactive tracer into the body. The radioactive tracer accumulates in the gallbladder, and images are collected based on how the radioactive tracer travels through the system and how the radiation is absorbed by the tissues.


Gallbladder scans are also performed to:


  • Help determine the cause of pain in the upper right side of the abdomen
  • Evaluate the function of the gallbladder
  • Help determine the cause of jaundice


A gallbladder scan typically takes about one to two hours to perform, but can last up to four hours.

Nuclear medicine locations

Scripps Health offers nuclear medicine services at the following locations in San Diego County.