General Nuclear Medicine

Nuclear medicine is a type of medical imaging that uses extremely small amounts of radioactive material to diagnose or treat a variety of conditions. Nuclear medicine has numerous applications, which include:

  • Providing information on how well an organ is functioning
  • Determining blood flow
  • Detecting tumors
  • Delivering radiation treatment

UC San Diego Health System is a leader in the field of advanced nuclear medicine diagnostics and treatments, offering a full spectrum of procedures. We are one of the few medical centers in the region to be certified in BEXXAR® therapy, an innovative radio-immunotherapy for non-Hodgkin’s lymphoma.

As an academic medical center, our range and quality of services makes us a preferred referral center for many other hospitals as well as for numerous specialty physicians. Our services are available at both our Hillcrest and La Jolla - Thornton locations.

How it Works

In most nuclear medicine procedures, small amounts of radioactive materials, called radiopharmaceuticals, are given by mouth or injected. Depending on the type of radiopharmaceutical, it then accumulates in a specific organ or tissues. Due to the small amount of actual physical material injected, there is no pharmacologic effect or toxicity associated with these radiopharmaceuticals, which are also known as radiotracers.

For diagnostic nuclear medicine procedures, the location of the accumulation is then imaged by special cameras or scanners to generate nuclear medicine images of the body's distribution of the radiotracer.

  • Unlike other types of imaging such as x-rays, nuclear medicine diagnostic procedures provide information about the function of nearly every human organ.
  • For even more detail, nuclear medicine scans can be superimposed with CT or MRI, a process known as PET/CT or SPECT/CT (SPECT scan).
  • PET is Positron Emission Tomography and SPECT is Single Photon Emission Computed Tomography

For nuclear medicine treatment procedures, the radiopharmaceuticals bind to or target specific cells or tissues in the body, for example, detecting and destroying cancer cells.

  • Nuclear medicine treatments can be used to provide stronger, more targeted, more effective radiation therapy than conventional external radiation techniques, especially when there are many lesions in the body.


We employ a variety of sophisticated nuclear medicine diagnostic procedures, including:

  • Myocardial perfusion imaging for coronary artery and heart disease
  • Thyroid function imaging for evaluation of thyroid disorders
  • Lung perfusion and ventilation function imaging
  • Gastric emptying study to evaluate gastric emptying time
  • Liver, gallbladder and spleen functional imaging
  • Renal function testing for kidney disease
  • Blood volume measurements for diagnosis of heart failure and other conditions
  • Gastrointestinal bleed study to detect internal bleeding
  • Cerebral blood flow study for detection of stroke and prediction of imminent stroke
  • Scans to detect infection, tumors or fractures


Some of the cutting-edge nuclear medicine treatments performed at UC San Diego Health System include:

Targeted antibody internal radiation therapy:
Used for the treatment of non-Hodgkin’s lymphoma, this intravenous therapy is composed of the antibody and the radioisotope Iodine-131 or Yittrium-90. The antibody identifies and sticks to the cancer cells and the radioisotope gives off radiation to destroy the cells. This treatment is FDA approved for patients who have already received chemotherapy or Rituxun or a combination of both, whose disease has not responded to the therapy or has returned.

Selective Internal Radiation Therapy (SIRT):
Used for palliative treatment for inoperable liver cancer, this treatment is administered through the artery that carries blood to the liver. SIRT uses microscopic beads containing radiative material to deliver concentrated radiation to liver tumors. It enables a radiation level around the tumors of up to 50 times the dosage that could be safely delivered by conventional external radiation treatment.

  • Although not regarded as a cure, SIRT can increase patients’ life expectancy and improve quality of life.


To learn more about our services, to make an appointment or to refer a patient, please call 858-657-7000.