A scintigraphy is a nuclear medicine test that generates images of parts of the body that will help the physician visualize the functioning of organs. A small amount of mildly radioactive tracer material is swallowed or injected into a vein. The material concentrates in the part of the body to be studied. A device called gamma camera captures the signal emitted by the radioactive material and converts it into an image. This image is called a scintiscan. Scintigraphy can be static (where the device is stationary) or dynamic (where the device scans over the part of the body being examined).

Many organs, including the brain, the thyroid gland, the lungs, the heart, the liver, the kidneys, the spleen as well as the bones can be observed through scintigraphy. The amount of radiation absorbed during this test is low. Furthermore, the swallowed or injected radioactive material is rapidly flushed through the body by the kidneys.

Objective

The objective of this test is to provoke cardiac stress through physical exercise (walking or running on a treadmill). The imaging technique is used to watch the change in blood flow due to exercise. When the heart is working hard, its blood vessels fill with blood to supply it with additional oxygen. The test allows us to see how this blood is distributed throughout the heart muscle. The radioactive substance that is injected into the body enables us to monitor its flow.

Pictures are taken before and after patients exert themselves on the treadmill. The physician then compares the results to provide information on the patient's condition.

Contraindications

People with certain heart problems (e.g., severe arrhythmia, recent heart attack) or who are unable to take this type of test (e.g., physical disability).

Preparation

• It is important that you bring an up-to-date list of your various medications on the day of the exam.
• Wear comfortable footwear.
• It is generally recommended to fast for at least 3 hours before the examination. However, recommendations may vary depending on the centre and the person's health condition.
• You may be asked not to have coffee and certain medications before the examination. In doubt, do not hesitate to contact the centre where the examination will take place to clarify any unclear situation.

Duration

Generally, each imaging session can last between 30 and 60 minutes. The total duration of the examination may vary depending on the number of images to be taken and the waiting time required between each of them.

Side effects

Because this test requires a great deal of physical effort, some people experience chest pain afterwards.

Objective

The objective of this test is to provoke cardiac stress by injecting the patient with Persantine (dipyridamole). The imaging technique is used to watch the change in blood flow caused by the drug. When the heart is working hard, its blood vessels fill with blood to supply it with additional oxygen. The test allows us to see how this blood is distributed throughout the heart muscle. The radioactive substance that is injected into the body enables us to monitor its flow. Persantine tests are administered to those who are unable to run on a treadmill.

Images are taken before and after the Persantine injection. The physician then compares the results to provide information on the patient's condition.

Contraindications

This test is associated with several contraindications, including:

• Allergy to Persantine or theophylline
• Severe asthma
• Angina (unstable angina) or heart attack within the last 96 hours
• Hypotension
• Recent stroke

Preparation

• It is generally recommended to fast for at least 3 hours before the examination. However, recommendations may vary depending on the centre and the person's health condition.
• Avoid any products that may contain caffeine 24 to 48 hours before the test.
• Continue taking medication as usual on the day of the test. Some physicians may ask their patients to stop taking their heart medication on the day of the procedure. Once again, it is very important that you follow the specific recommendations issued by the centre where you will be going for your test.
• It is important that you bring a list of your medications on the day of this exam.

Procedure

An intravenous catheter is inserted into the patient's forearm. A radioactive tracer material is then injected and images are taken. Afterwards, Persantine is administered to the patient and the radioactive material is injected once again. A second set of pictures is then taken.

Duration

Generally, each imaging session can last between 30 and 60 minutes. The total duration of the examination may vary depending on the number of images to be taken and the waiting time required between each of them.

Side effects

Persantine causes a great deal of stress on the heart. Some people experience chest pain afterwards. Headache, nausea, hot flushes and dizziness have been reported.

Objective

The objective of this test is to assess the balance between the bone formation and destruction (bone metabolism). It can highlight areas of inflammation on the bones as well as lesions that are not always painful or visible on other tests. Bone scintigraphy helps identify metastases, fractures and osteoarthritis, among others.

Preparation

No specific preparation is required before the examination.

Procedure

Bone scintigraphy is simple and painless but is quite lengthy. A radioactive agent is injected into a vein. Images may be taken as the radioactive agent is making its way to the bones. The patient must then wait a few hours. During this time, one can eat and drink. Drinking plenty of fluids during this time is highly recommended as it improves the distribution of the product and also helps flush it out after the test. Patients are asked to urinate right before the images are taken.

Duration

This test takes 4 to 6 hours to complete.

Side effects

It is possible to experience pain or inflammation at the injection site.

Objective

This test is used to assess the shape, size and position of the thyroid gland.

Preparation

No specific preparation is required before the examination.

However, it is important to inform the centre where the examination will take place if you have had a radiological examination involving iodine within the past 4 to 8 weeks. It is also necessary to mention to the centre if you are taking medication for the thyroid gland (e.g., levothyroxine (Synthroid), liothyronine (Cytomel), propylthiouracil (PTU)) or natural products containing iodine, as you may be asked to stop taking them for a few days to a few weeks before the examination.

Procedure

The patient is injected with a radioactive agent and is then asked to wait 15 to 20 minutes. After the waiting period is over, images are taken. This examination is usually performed along with other tests. Other thyroid tests are generally ordered (thyroid uptake).

Duration

This test generally takes 45 to 60 minutes to complete.

Side effects

It is possible to experience pain or inflammation at the injection site.