Nuclear Medicine General
Nuclear Medicine Menu
General | Cardiac
- What is General Nuclear Medicine?
- What are some common uses of the procedure?
- How should I prepare for the procedure?
- What does the equipment look like?
- How does the procedure work?
- How is the procedure performed?
- What will I experience during the procedure?
- Who interprets the results and how do I get them?
- What are the benefits vs. risks?
- What are the limitations of General Nuclear Medicine?
- Which Health Diagnostics facilities offer this service?

What is General Nuclear
Medicine?
Nuclear medicine is a subspecialty within
the field of radiology. It comprises diagnostic examinations
that result in images of body anatomy and function.
The images are developed based on the detection of
energy emitted from a radioactive substance given
to the patient, either intravenously or by mouth.
Generally, radiation to the patient is similar to
that resulting from standard x-ray examinations.
What are some common
uses of the procedure?
Nuclear medicine images can assist the physician
in diagnosing diseases. Tumors, infection and other
disorders can be detected by evaluating organ function.
Specifically, nuclear medicine can be used to:
- Analyze kidney function
- Image blood flow and function of the heart
- Scan lungs for respiratory and blood-flow problems
- Identify blockage of the gallbladder
- Evaluate bones for fracture, infection, arthritis or tumor
- Determine the presence or spread of cancer
- Identify bleeding into the bowel
- Locate the presence of infection
- Measure thyroid function to detect an overactive or underactive thyroid
How should I prepare for the
procedure?
No preparation is required for bone, hepatic hemongioma
and gallium scans. The following preparation is required:
Renal- Drink two 8-ounce glasses of water
during the 2 hours prior to the exam.
Captopril Renal- Do not eat or drink anything
except water 4 hours prior to the exam. Discontinue ace inhibitors,
calcium antagonists and diuretic medications 48 hours prior
to your exam.
Gallbladder- Do not eat or drink anything
except water 4 hours prior to exam.
Gastric Empty or Meckels- Do not eat or drink
anything except water 12 hours prior to exam. Call for other
special instructions.
Thyroid- Do not take thyroid medication 4-6
weeks prior to exam. You should not receive any x-ray dye for
2 weeks prior to exam. No solid food past midnight prior to
exam. Do not take PTU/Tapazole 1 week prior to exam. Pregnant
or nursing patients are prohibited from taking this exam.
What does the equipment
look like?
During most nuclear medicine examinations,
you will lie down on a scanning table. Consequently,
the only piece of equipment you may notice is the
specialized nuclear imaging camera used during
the procedure. It is enclosed in metallic housing
designed to facilitate imaging of specific parts
of the body. It can look like a large round metallic
apparatus suspended from a tall, moveable post
or a sleek one-piece metal arm that hangs over
the examination table. The camera can also be located
within a large, doughnut-shaped structure similar
in appearance to a computed
tomography (CT) scanner. Sometimes, the camera
is beneath the table out of view.
A nearby computer console, possibly in another room,
processes the data from the procedure.
How does the procedure
work?
You are given a small dose of radioactive material,
usually intravenously but sometimes orally, that
localizes in specific body organ systems. This compound,
called a radiopharmaceutical agent or tracer, eventually
collects in the organ and gives off energy as gamma
rays. The gamma camera detects the rays and works
with a computer to produce images and measurements
of organs and tissues.
How is the procedure
performed?
A radiopharmaceutical agent is usually administered
into a vein. Depending on which type of scan is being
performed, the imaging will be done either immediately,
a few hours later, or even several days after the
injection. Imaging time varies, generally ranging
from 20 to 45 minutes.
The radiopharmaceutical that is used is determined
by what part of the body is under study, since some
compounds collect in specific organs better than
others. Depending on the type of scan, it may take
several seconds to several days for the substance
to travel through the body and accumulate in the
organ under study, thus the wide range in scanning
times.
While the images are being obtained, you must remain
as still as possible. This is especially true when
a series of images is obtained to show how an organ
functions over time.
After the procedure, a physician with specialized
training in nuclear medicine checks the quality of
the images to ensure that an optimal diagnostic study
has been performed.
What will I experience
during the procedure?
Some minor discomfort during a nuclear medicine
procedure may arise from the intravenous injection,
usually done with a small needle. With some special
studies, a catheter may be placed into the bladder,
which may cause temporary discomfort. Lying still
on the examining table may be uncomfortable for some
patients.
Most of the radioactivity passes out of your body
in urine or stool. The rest simply disappears through
natural loss of radioactivity over time.
Who interprets the
results and how do I get them?
Most patients undergo a nuclear medicine examination
because their primary care physician has recommended
it. A physician who has specialized training in nuclear
medicine will interpret the images and forward a
report to your physician. It usually takes a day
or so to interpret, report and deliver the results.
What are the benefits vs. risks?
Benefits
- The functional information provided by nuclear medicine examinations is unique and currently unattainable by using other imaging procedures. For many diseases, nuclear medicine studies yield the most useful information needed to make a diagnosis and to determine appropriate treatment, if any.
- Nuclear medicine is much less traumatic than exploratory surgery, and allergic reaction to the radiopharmaceutical material is extremely rare.
Risks
- Because the doses of radiopharmaceutical administered are very small, nuclear medicine procedures result in exposure to a small dose of radiation. Nuclear medicine has been used for more than five decades, and there are no known long-term adverse effects from such low-dose studies.
- As with all radiologic procedures, be sure to inform your physician if you are pregnant. In general, exposure to radiation during pregnancy should be kept to a minimum.
- Allergic reactions to the radiopharmaceutical can occur, but are extremely rare.
What are the limitations
of General Nuclear Medicine?
Nuclear medicine procedures are time-consuming.
They involve administration of a radiopharmaceutical,
acquisition of images and interpretation of the results.
It can take hours to days for the radiopharmaceutical
to accumulate in the part of the body under study.
Imaging can take up to three hours to perform, though
new equipment is available that can substantially
shorten the procedure time.
Which Health Diagnostics facilities offer this service?

