what is vq scan
From Wikipedia, the free encyclopedia. A ventilation/perfusion lung scan, also called a V/Q lung scan, is a type of medical imaging using scintigraphy and medical isotopes to evaluate the circulation of air and blood within a patient's lungs, in order to determine the ventilation/perfusion ratio.he ventilation and perfusion phases of a V/Q lung scan are performed together and may include a chest x-ray for comparison or to look for other causes of lung disease. A defect in the perfusion images requires a mismatched ventilation defect to indicate pulmonary embolism.