Question about a VQ Scan (lung scan)?

Question

I just had a lung scan done. I could see on the black screen that all these tiny white dots made up an image of one of my lungs. Directly beside that though, only part of the other lung was shown by the little white dots. I am assuming this is showing the lung's function? The o2 being taken in. Is this correct?

If it helps, I am in my 20s, born with congenital heart disease.

Details...

Ok, born with Transposition. Had 3 surgeries for this including a 2 part switch. Then had aortic valve replacement 5 years ago and now have a metal valve. Lately the docs have been paying attention to the narrowing of my pulmonary artery or left ventricle...I don't know which, because I don't know what either of these are and I forget what the doctor said...they just sound familiar. What makes more sense for it to be??

Answer 1

The V stands for Ventilation and the Q for Perfussion so the scan measures the air flow in the lungs and compares that with the blood flow. The left lung should appear to have a deficit due to the fact that the heart takes up the middle lower portion of the left chest. Congenital heart disease itself should not be a reason to do a VQ scan unless you have clinical symptoms of heart failure. Even in that circumstance I can think of many better and far more informative tests. The primary reason for a VQ scan is to identify deficits in blood flow due to blood clots such as pulmonary embolism which is not likely to be your circumstance. If you provide more details perhaps I will be able to give you a better answer.

Answer 2

V is ventilation
Q is blood flow

They are cheching to see if you have blood flow that matches the air exchange in your lungs.

"The ventilation-perfusion scan is a nuclear scan so named because it studies both airflow (ventilation) and blood flow (perfusion) in the lungs. The initials V-Q are used in mathematical equations that calculate airflow and blood flow. The purpose of this test is to look for evidence of a blood clot in the lungs, called a pulmonary embolus, that lowers oxygen levels, causes shortness of breath, and sometimes is fatal."