Nuclear Medicine Overview

Nuclear medicine involves using radioactive substances to diagnose and treat certain medical conditions. The field of nuclear medicine is a radiology subspecialty that includes nuclear medicine technologists and nuclear medicine physicians.

Nuclear medicine technologists and nuclear medicine physicians work closely with each other to perform and interpret the results of nuclear medicine tests. Nuclear medicine tests include bone scans, lung scans, positron emission tomography (PET) scans, and single photon emission computed tomography (SPECT).

Diagnostic nuclear tests usually are painless and noninvasive and often allow for earlier detection than standard radiology procedures (e.g., x-ray, CT scan, MRI scan). They can be used to examine the gastrointestinal (GI) tract (e.g., small intestines, colon), brain, heart, gallbladder, kidneys, thyroid, and bones.

Nuclear medicine tests often are used to locate infections and blockages, detect abnormal bleeding, and evaluate blood flow and organ function. They also can be used to detect bone fractures, arthritis, tumors, and other injuries and disorders.

In nuclear medicine tests, a small amount of a radioactive substance (i.e., radionuclide, radiopharmaceutical) is injected into a vein, inhaled, or administered orally. This substance collects in different amounts in tissues throughout the body and gives off gamma rays (high energy x-rays).

A special device (e.g., scanner, probe) is used to detect and measure radiation levels in areas of the body that are being examined and a computer uses this information to create images. These images indicate abnormal changes in metabolism (e.g., as a result of injury or disease) as higher-than-expected or lower-than-expected concentrations of radiation. Nuclear medicine physicians study the images to obtain important information about certain medical conditions.

In addition to diagnostic tests, nuclear medicine specialists also perform treatments, such as radioactive iodine therapy. In this treatment, radioactive iodine (I-131) is swallowed, absorbed by the thyroid gland, and destroys abnormal thyroid tissue. Radioactive iodine therapy is used to treat a number of thyroid disorders, including overactive thyroid (hyperthyroidism), Graves' disease, goiters, thyroid nodules, and thyroid cancer.

Nuclear medicine specialists work in clinical settings, such as hospitals, outpatient imaging centers, and private practices, or in research institutions. Nuclear medicine technologists also may work in sales (e.g., selling medical equipment used in nuclear medicine), in training other health care providers in the use of nuclear medicine equipment, or in radiation safety.

Nuclear medicine specialists use a number of safety precautions to reduce the risk for radiation exposure, which is low in most cases. Precautions include wearing a device that continuously measures radiation levels, using protective devices (e.g., syringes, containers, and bins shielded using leaded glass) and wearing gloves.

Nuclear Medicine Physicians

Nuclear medicine physicians are radiologists who have completed additional training. After graduating from an accredited medical school, radiologists must pass a licensing examination and complete at least four years of graduate medical education (called a residency). Radiologists often are board certified by the American Board of Radiology or the American Osteopathic Board of Radiology.

To specialize in nuclear medicine, radiologists must complete one year of clinical residency, followed by two years of additional training in nuclear medicine. Nuclear medicine physicians who have attained the highest levels of education and training may be certified through the American Board of Nuclear Medicine.

Nuclear Medicine Technologists

Nuclear medicine physicians work closely with technologists. A career as a nuclear medicine technologist requires a strong background in mathematics, anatomy and physiology, chemistry, and physics. In many cases, nuclear medicine technologists have received training in standard radiological procedures (e.g., x-rays, CT scan, MRI scan).

To specialize in nuclear medicine, radiology technologists must complete a one-year program to attain a certificate, a two-year program to attain an associate's degree, or a four-year program to attain a bachelor's degree. Nuclear medicine programs emphasize physical sciences; effects of radiation exposure; and radiation procedures, techniques, and safety. These programs may accredited by the Joint Review Committee on Education Programs in Nuclear Medicine Technology.

Following successful completion of a one-year nuclear medicine technology program, technologists take examinations administered by the American Registry of Radiologic Technologists (ARRT) and the Nuclear Medicine Technologist Certification Board (NMTCB). After passing these exams, the technologist is a certified nuclear medicine technologist.

Certified nuclear medicine technologists may continue their education in an associate's, bachelor's, or master's program. After attaining an advanced degree, the technologist may become a supervisor, instructor, director, or administrator.

Nuclear medicine technologists may complete additional education and training to subspecialize in areas such as nuclear cardiology or computer analysis. Some states also require technologists to be licensed to practice nuclear medicine.

Publication Review By: Stanley J. Swierzewski, III, M.D.

Published: 28 Feb 2008

Last Modified: 13 Oct 2015