label: Pulmonary perfusion defect
label_lc: pulmonary perfusion defect
description: "Lack of blood perfusion in a specific area of the lung. Pulmonary ventilation (V) and Perfusion (Q) scan, also known as lung V/Q scan, is a nuclear test that uses the perfusion scan to delineate the blood flow distribution and the ventilation scan to measure airflow distribution in the lungs."