Pulmonary ventilation/perfusion scan

Alternative names:

scan - lung ventilation/perfusion; V/Q scan

Normal values:

A ventilation and perfusion scan should be correlated with a chest X-ray. There should be uniform uptake of radioisotope in all portions of the lungs with equal distribution in both lungs.

What abnormal results mean:

A decreased uptake of radioisotope during a perfusion scan indicates a problem with blood flow, including occlusion of the pulmonary arteries. A localized decreased in perfusion scan uptake (particularly when ventilation scan is normal) may indicate pulmonary embolus. Larger areas of decreased perfusion scan uptake may indicate a condition such as pneumonitis.

A decreased uptake of radioisotope during a ventilation scan may indicate reduced breathing and ventilation ability or airway obstruction. A decreased ventilation uptake (plus X-ray evidence of consolidation) may indicate pneumonia. Larger areas of poor uptake may indicate chronic smoking or COPD.