V/Q Scan

Ventilation and perfusion are normally coupled through regional physiology. Gravity, airway caliber, pulmonary vascular tone, and lung volume all affect distribution, but a healthy region should still receive enough air and blood to participate in gas exchange. Pulmonary embolism disrupts perfusion by obstructing arterial flow. Distal lung tissue can remain ventilated while blood cannot reach it, producing dead-space physiology and possible hypoxemia. V/Q imaging visualizes this relationship. Matched defects often point toward parenchymal disease, airway disease, prior surgery, effusion, or other non-embolic explanations. Mismatched segmental perfusion defects raise concern for PE. Modern reporting may use probability language, binary PE present/absent systems, SPECT or SPECT/CT interpretation, or local structured reporting. The NP should avoid treating the report phrase in isolation; management depends on clinical probability, hemodynamic stability, bleeding risk, competing diagnoses, and whether further testing is needed. For NP certification preparation (United States), items rarely announce the topic in the first sentence. Anchor to objective data, trajectory, and the safest next step for the role named in the stem before distractors compete. Presenting picture Clients with concerns related to NP certification...