What is a VQ Scan? Let's talk about it simply!

As you know, doctors use various tests to find problems inside our bodies. You are probably familiar with things like X-rays and CT scans. Today we are going to talk about a slightly different type of scan that is also used to look in depth at the functioning of our lungs. This is called a VQ scan. Although the name may sound a bit complicated, it is actually quite simple.

Simply put, what is a VQ scan?

A VQ scan is a two-part, non-invasive test that takes pictures of your lungs and measures the airflow and blood flow in them.

The 'V' in the name stands for Ventilation , which is how air moves in and out of your lungs. The 'Q' stands for Perfusion , which is how much blood is flowing to the tiny blood vessels in your lungs. So it's sometimes called a Ventilation-Perfusion scan, lung scan, or lung scintigraphy.

In what situations is this scan used?

Doctors often use a VQ scan to check for a blood clot in your lungs (Pulmonary Embolism, or PE) . This can be life-threatening if not treated properly. It is also used to diagnose CTEPH (Chronic Thromboembolic Pulmonary Hypertension) , a condition that causes high blood pressure in the blood vessels of the lungs.

Not only that, but this scan also helps to check the function of your lungs in several other ways.

• After a lung transplant.
• Before surgery to remove a lung or part of it.
• When diagnosing or treating other lung conditions, such as COPD (Chronic Obstructive Pulmonary Disease) .

What is the difference between a VQ scan and a CT scan?

While both types of scans take pictures of the lungs and help detect problems like blood clots, there are clear differences between the two. Let's take a look at them in a table.

How should I prepare before the scan?

Actually, this scan doesn't require any special preparation. You can eat normally and take your medications. However, you should definitely tell your doctor about the following:

• If you are pregnant or suspect you are pregnant: This scan involves a small amount of radiation, so it is not safe for the unborn baby. In such cases, your doctor may recommend another test.
• If you are a breastfeeding mother: Since the substance used for the scan can pass into breast milk, your doctor will give you special instructions about how to breastfeed your baby for a day or two after the scan.
• If you have difficulty staying still in one position for several minutes: If you move during the scan, the images will not be clear. So it is important to inform us about this in advance.

A chest X-ray is usually ordered within 24 hours of the VQ scan. The information obtained from this will help the doctor understand the results of the VQ scan.

What happens during the scan?

This test takes between 30 and 60 minutes to complete. It has two parts. Some people only have one part done, but most people have both parts done on the same day.

Part One: Ventilation Scan

This involves looking at how air enters your lungs.

1. First, you will be fitted with a mouthpiece or a mask that covers your mouth and nose. You may also need to put a small clip on your nose to ensure that you only breathe through your mouth.

2. Then, through a tube connected to this device, a very small amount of a radioactive substance (tracer) is added to the air you breathe. Think of it like putting a small colored tag on the air you breathe.

3. You will be made to lie down on a special bed and sent inside a machine that looks like a cylinder. Or you will be made to sit in a chair and placed in front of a camera.

4. As you breathe through this mask, a special camera will take pictures of your lungs. You may be turned into different positions to take the necessary pictures.

Part Two: Perfusion Scan

This section is completed as soon as the ventilation scan is completed. This section looks at how blood flows to the lungs.

• This time, the radioactive substance (tracer) is not inhaled. Instead, it is injected into a vein in your arm through an IV .
• Then, using the same camera as before, they take pictures of the blood flowing through your lungs.

How do I get the results after the scan?

You can return to your normal activities after the scan. The radioactive material that was injected into your body will naturally leave your body through your breath, urine, and stool within a few hours or days. You will usually get your results within 24 hours.

If the results report says "Normal" or "Low probability," that means there is no blood clot. If it says something like "Intermediate probability," that means it is unclear, and more tests may be needed. If it says "High probability," that means there is a high chance of a blood clot, and your doctor will talk to you about the treatment you need.

When do you need to see a doctor urgently?

If you have symptoms of a blood clot in your lungs (Pulmonary Embolism) , it is an emergency. Call your doctor immediately, or go to the Emergency Department (ETU) at your nearest hospital. Watch for these symptoms:

• Sudden difficulty breathing.
• Sharp pain in the chest, arm, shoulder, neck, or jaw.
• Coughing with or without blood.
• Pale skin and sticky sweat.
• Blue discoloration of the skin, lips, or fingernails (cyanosis).
• Heart rate increases.
• Excessive sweating.

VQ scan Sinhala, VQ scan, lung scan, blood clots in the lungs, Pulmonary Embolism Sinhala, ventilation perfusion scan, lung scan