A lung gallium scan is a type of nuclear scan that uses radioactive gallium to identify swelling (inflammation) in the lungs.
A lung scan is an imaging test to look at your lungs and help diagnose certain lung problems. A lung scan may also be used to see how well treatment is working. A lung scan is a type of nuclear imaging test. This means that a tiny amount of radioactive matter is used during the scan.
How the Test is Performed
Gallium is injected into a vein. The scan will be taken 6 to 24 hours after the gallium is injected. (Test time depends on whether your condition is acute or chronic)
During the test, you lie on a table that moves underneath a scanner called a gamma camera. The camera detects the radiation produced by the gallium. Images are displayed on a computer screen.
During the scan, it is important that you keep still to get a clear image. The technician can help make you comfortable before the scan begins. The test takes about 30 to 60 minutes.
How to Prepare for the Test
Several hours to 1 day before the scan, you will get an injection of gallium at the place where the testing will be done.
Just before the scan, remove jewelry, dentures, or other metal objects that can affect the scan. Take off the clothing on the upper half of your body and put on a hospital gown.
How the Test will Feel
The injection of gallium will sting, and the puncture site may hurt for several hours or days when touched.
The scan is painless, but you must stay still. This may cause discomfort for some people.
Why the Test is Performed
This test is usually done when you have signs of inflammation in the lungs. This is most often due to sarcoidosis or a certain type of pneumonia.
Normal Results
The lungs should appear of normal size and texture and should take up very little gallium.
What Abnormal Results Mean
If a large amount of gallium is seen in the lungs, it may mean any of the following problems:
- Sarcoidosis (disease in which inflammation occurs in the lungs and other tissues of the body)
- Other respiratory infections, most often a type of pneumonia caused by the fungus Pneumocystis jirovecii
Risks
There is some risk to children or unborn babies. Because a pregnant or nursing woman may pass on radiation, special precautions will be made.
For women who are not pregnant or nursing and for men, there is very little risk from the radiation in gallium, because the amount is very small. There are increased risks if you are exposed to radiation (such as x-rays, and scans) many times. Discuss any concerns you have about radiation with the health care provider who recommends the test.
The risk from the radioactive tracer is very low. The amount used in the test is very small. You may feel some slight discomfort when the tracer is injected. Allergic reactions to the tracer are rare, but they may happen.
Lying on the scanning table during the procedure may cause some discomfort or pain for certain people.
Tell your healthcare provider if you:
- Are allergic to or sensitive to medicines, contrast dyes, or latex
- Are pregnant or think that you might be pregnant since the scan may not be safe for the unborn baby
- Are breastfeeding since the tracer may contaminate your breast milk
You may have other risks that are unique to you. Let your healthcare provider know about all your medical conditions.
Make a list of questions you have about the procedure. Be sure to discuss these questions and any concerns with your healthcare provider prior to the procedure. Consider bringing a family member or trusted friend to the medical appointment to help you remember your questions and concerns.
Certain things can make a lung scan less accurate. These include:
- Having radioactive tracer in your body from another recent nuclear medicine test
- Pneumonia or obstructive lung disease
- Structural problem in your chest
- Ventilation scan mask that is loose or does not fit well
How do I prepare for a lung scan?
- PRECAUTIONS: If you are pregnant or think you may be pregnant, please check with your doctor before scheduling the exam. We will discuss other options with you and your doctor.
- BREASTFEEDING: If you are breastfeeding, you should notify your health care provider due to the risk of contaminating breast milk with the tracer.
- CLOTHING: You may be asked to change into a patient gown. A gown will be provided for you. Lockers are provided to secure your personal belongings. Please remove all piercings and leave all jewelry and valuables at home.
- EAT /DRINK: Generally, no prior preparation, such as fasting or sedation, is required prior to a lung scan.
- ALLERGIES: Notify the radiologist or technologist if you are allergic to or sensitive to medications, contrast dyes, or iodine. The injection of the radiotracer may cause some slight discomfort. Allergic reactions to the radiotracer are rare but may occur.
- CHEST X-RAY: A chest X-ray may be performed prior to the procedure if one has not already been obtained in the previous 24 to 48 hours.
Based on your medical condition, your doctor may request other specific preparation.
What happens during a lung scan?
You may have a lung scan as an outpatient or as part of your stay in a hospital. The way the test is done may vary depending on your condition and your healthcare provider’s practices.
You may have either a perfusion scan or a ventilation scan. Or you may have both scans. If you have both scans, one will be done right after the other.
Generally, a lung scan follows this process:
- You will be asked to remove any clothing, jewelry, or other objects that may get in the way of the scan.
- You may be asked to remove clothing. If so, you will be given a gown to wear.
- For a perfusion lung scan, an IV line will be started in a hand or arm so that you can be given the radioactive tracer.
- The radiologist will slowly inject the tracer into your vein while you are lying flat on the test table.
- The tracer will collect in the blood vessels of your lungs. The radiologist will use the scanner to take images of the lungs. You will be helped into several different positions during the test. This will let the radiologist take images of the lungs from different angles.
- For a ventilation scan, you will breathe in a gas with the tracer in it through a face mask or a tracer may be injected.
- You will then be asked to hold your breath for a short time. The radiologist will use the scanner to take images of your lungs while you are holding your breath. He or she will continue to take images while you breathe in the tracer for a few more minutes. Be careful not to swallow the tracer. Swallowing the tracer could affect the quality of the images.
- After the tracer gas has collected in your lungs, the radiologist will remove the face mask. As you breathe normally, the tracer will gradually leave your lungs.
- Once the scan is done, the IV line will be removed.
The lung scan is not painful. But you may have some discomfort or pain from lying still during the test. This may because of recent surgery or a joint injury. The technologist will use all possible comfort measures and do the scan as quickly as possible to minimize any discomfort or pain.
What happens after a lung scan?
You may be watched for a short while after the test for any signs that mean you are allergic to the tracer.
You should move slowly when getting up from the scanner table to avoid any dizziness or lightheadedness.
You may be told to drink plenty of fluids and empty your bladder often for 1 to 2 days after the scan. This will help flush the radioactive tracer from your body.
The medical staff will check the IV site for any signs of redness or swelling. Tell your healthcare provider if you see any pain, redness, or swelling at the IV site after you go home. These may be signs of infection or another type of reaction.
You should not have any other nuclear medicine tests for the next 24 to 48 hours after your lung scan.
You may go back to your usual diet and activities as directed by your healthcare provider.
FAQ
What is the best scan for lungs?
- The only recommended screening test for lung cancer is low-dose computed tomography (also called a low-dose CT scan, or LDCT). During an LDCT scan, you lie on a table and an X-ray machine uses a low dose (amount) of radiation to make detailed images of your lungs. The scan only takes a few minutes and is not painful.
Why would a doctor order a CT scan of the lungs?
- Many times, a CT scan is ordered by a doctor after noticing something abnormal in an X-ray. Although the CT scan cannot give a definitive diagnosis, it is helpful in the evaluation of lung diseases and conditions such as pneumonia, cancer, blood clots or damage caused by smoking.
How do they perform a lung scan?
- A radioactive tracer is injected into a vein in your arm. It travels through your blood and into the lungs. Pictures from this scan can show areas of the lungs that aren’t getting enough blood. If both scans are done, the test is called a V/Q scan.
Which is better a lung CT scan or MRI?
- In general, CT is superior to MRI as an all-around tool for imaging the wide range of thoracic abnormalities that can be present in patients with lung cancer. Limited availability and longer examination time of MRI compared with CT have restricted the use of thoracic MRI.
Can a CT scan detect a lung infection?
- A CT scan of the chest can help find problems such as infection, lung cancer, blocked blood flow in the lung (pulmonary embolism), and other lung problems. It also can be used to see if cancer has spread into the chest from another area of the body. A low-dose CT scan is a different type of chest CT scan.
How do you prepare for a lung CT scan?
- You don’t need to do anything to prepare for a chest CT scan, and you can eat and drink as usual before the test. Before the scan begins, you will need to remove all jewelry as this can interfere with the images. You will need to wear a hospital gown during the scan.
Are our heart and lung scans worth it?
- Heart scans are considered most useful for those with a known “moderate” risk of heart disease or for those whose risk is uncertain. Your risk for heart disease can be calculated based on your age, sex, blood pressure, cholesterol levels, and tobacco use.
What does an abnormal lung CT scan mean?
- An abnormal report means that your doctor saw something in the image of your lungs that needs to be looked at further. Sometimes small spots, called pulmonary (lung) nodules, are seen on the CT scan image of your lungs. These are very common and are almost always not cancer (benign).
Why do I need a lung scan?
- Lung scans are most often used to diagnose and find blood clots or other small masses called emboli in the lungs. But your healthcare provider may also use the scan to help diagnose other lung conditions.
How long is a lung scan?
- An initial set of pictures (images) will be taken of your lungs using a special nuclear medicine camera. The camera does not produce any radiation, it simply detects and records the distribution of the radioactive material in your lungs. This part of the test will take about 15 to 20 minutes.
What can a CT scan miss?
- CT scans can be misread or misinterpreted. Imaging tests usually can’t tell if a change has been caused by cancer. CT scans can produce false negatives and false positives. CT scan can miss cancer or miss tumors in other areas of the body.
What can be diagnosed from a lung CT?
Chest CT can demonstrate various lung disorders, such as:
