Nuclear medicine is a division of radiology that uses small amounts of radioactive material to evaluate, diagnose and treat disease conditions. Nuclear medicine examinations and imaging tests use radioactive substances to create uniquely detailed images that enable physicians to examine both the anatomy and function of various regions of the body.
Benefits of Nuclear Medicine
Because the human body is opaque, and because exploratory surgery is painful and complicated, noninvasive diagnostic tests have been very important medical advances. Nuclear medicine goes beyond X-rays, CT scans and ultrasound to identify molecular and cellular activity within the body, helping doctors to diagnose diseases at their earliest stages. Just a minute amount of radioactive material is necessary to determine how well the body is functioning in terms of chemical and biological processes.
The primary benefits of nuclear medicine are that:
- It provides information otherwise only available through biopsy or surgery
- It provides more precise images than other diagnostic imaging tests
- It is safe, painless, and noninvasive
- It identifies diseases before symptoms appear, when they are most treatable
By using special cameras that interface with computers, nuclear medicine enables medical professionals to diagnose and treat diseases with fewer complications.
Types of Nuclear Medicine Imaging Techniques
There are several types of nuclear medicine imaging techniques, including:
- Bone scan
- Cardiovascular imaging
- Positron emission tomography (PET scan)
- Single photon emission computed tomography (SPECT scan)
The main difference between nuclear medicine imaging techniques and other imaging tests is that nuclear imaging techniques show the physiological function of the tissue or organs, while traditional imaging systems only show the anatomy or structure.
Uses of Nuclear Medicine Imaging Techniques
Nuclear medicine imaging techniques are used to detect many diseases and abnormalities. These include:
- Bone disorders
- Brain disorders
- Gastrointestinal disorders
- Heart and vascular disorders
They may also be used to detect dysfunction within the thyroid glands and within organs such as the lungs and kidneys.
Nuclear Medicine Procedures
Nuclear medicine obtains images of internal organs and body functions by having the patient ingest, inhale, or be injected with a radioactive substance prior to the test. These substances are known as radiopharmaceuticals or radiotracers. Images are created by the energy emitted by these radioactive substances. Sometimes nuclear scans are performed in conjunction with other types of imaging tests, such as CT or MRI scans, a process known as image fusion.
Nuclear medicine offers therapeutic procedures as well as diagnostic ones. A common form of nuclear treatment is one that uses radioactive iodine to treat thyroid cancer and other medical conditions of the thyroid gland. Patients with non-Hodgkin's lymphoma whose disease does not respond well to chemotherapy may also undergo a nuclear therapeutic procedure known as radioimmunotherapy (RIT).
Risks of Nuclear Medicine
Tests using radioactive substances are not recommended for pregnant women because of potential damage to the fetus. For most others, the benefits of nuclear medicine procedures outweigh any risks involved, though the patient should always discuss benefits and risks with their physicians in order to make informed decisions. Generally speaking, the risk level is low, but risks to be considered include:
- Adverse reaction to contrast dye
- Radiation injuries (burns) to skin and underlying tissue
- Radiation-induced hair loss or cataracts
- Radiation-induced cancers, which may occur later in life
The risks of nuclear medicine procedures vary widely according to the precautions taken by the facility in which they are administered. It is strongly recommended that patients carefully check the safety record of such facilities before undergoing any procedures involving nuclear medicine.