Overview of SPECT scan
A single-photon emission computerized tomography (SPECT) scan lets your doctor analyze the function of some of your internal organs. A SPECT scan is a type of nuclear imaging test, which means it uses a radioactive substance and a special camera to create 3-D pictures.
While imaging tests such as X-rays can show what the structures inside your body look like, a SPECT scan produces images that show how your organs work. For instance, a SPECT scan can show how blood flows to your heart or what areas of your brain are more active or less active.
Why SPECT did?
The most common uses of SPECT in the diagnosis or monitoring of brain disorders, heart problems, and bone disorders.
Single-photon emission computed tomography (SPECT) helps identify which parts of the brain are affected by:
- Clogged blood vessels
- Head injuries
Since the radioactive tracer highlights areas of the blood flow, SPECT can check for:
- Clogged coronary arteries. If the arteries that feed the heart muscle become narrowed or clogged, the portions of the heart muscle served by these arteries can become damaged or even die.
- Reduced pumping efficiency. SPECT can show how completely your heart chambers empty during contractions.
Areas of bone healing or cancer progression are usually highlighted on SPECT scans, which is why this type of test is increasingly used to help identify hidden bone fractures. SPECT scans can detect and track the progression of cancer that has spread to the bones.
For most people, SPECT scans are safe. If you receive an injection or infusion of radioactive tracer, you may experience:
- Bleeding, pain or swelling where the needle was inserted in your arm.
- Rarely, an allergic reaction to the radioactive tracer.
SPECT scans aren’t safe for women who are pregnant or breast-feeding because the radioactive tracer may be passed to the developing fetus or the nursing baby.
Risks of radiation
Your health care team uses a small amount of radiation to perform a SPECT scan, and the test is not associated with any long-term health risks. Talk to your doctor if you’re concerned about your exposure to radiation during a SPECT scan.
How do you prepare
It depends on your particular situation. Ask your healthcare team if you need to do any special preparations before having your SPECT scanned.
In general, you should:
- Leave the metal jewellery at home.
- Inform technicians if you are pregnant or breastfeeding.
- Make a list of all the medications and supplements you are taking.
What can you expect
During the exam
It involves two steps: X-ray injection (called a tracer) and the use of a SPECT machine to scan a specific area of your body.
Receiving a radioactive substance
You’ll receive a radioactive substance through an intravenous (IV) infusion into a vein in your arm. The tracer dose is very small. You may feel a cold sensation as it enters your body. You may be asked to lie quietly in a room for 20 minutes or more before your scan while your body absorbs the radioactive tracer. In some cases, you may need to wait several hours or, rarely, several days between the injection and your scan.
Your body’s more-active tissues will absorb more of the radioactive substance. For instance, during a seizure, the area of your brain causing the seizure may retain more of the radioactive tracer, which allows doctors to pinpoint the area of your brain causing your seizures.
After the test
Most of the radioactive tracer leaves your body through your urine within a few hours after your scan. Your doctor may instruct you to drink more fluids, such as juice or water, after your scan to help flush the tracer from your body. Your body breaks down the remaining tracer over the next few days.
A radiologist or doctor with advanced training in nuclear medicine will analyze the results of your scan and send them to your doctor. Pictures from your scan may show colours that tell your doctor what areas of your body absorbed more of the radioactive tracer and which areas absorbed less. For instance, a brain image might show a lighter colour where brain cells are less active and darker colours where brains cells are more active. Some scanned images show shades of grey, rather than colours.