It is a clinical decision tool that estimates the probability of pulmonary embolism using seven clinical criteria. Scores can be interpreted using a three-tier model (low/moderate/high) or a two-tier model (PE unlikely ≤4, PE likely >4). It guides the choice between D-dimer testing and CT angiography.

Low risk (<2 points): D-dimer — if negative, PE effectively ruled out. Moderate risk (2–6): D-dimer, proceed to CTPA if positive. High risk (>6): proceed directly to CTPA without waiting for D-dimer.

CT Pulmonary Angiography is the gold standard imaging test for diagnosing pulmonary embolism. It uses IV contrast and CT scanning to directly visualize blood clots in the pulmonary arteries. It is fast, widely available, and has high sensitivity and specificity.

They are two separate scoring systems. The Wells DVT score has 10 criteria and evaluates deep vein thrombosis probability. The Wells PE score has 7 criteria and evaluates pulmonary embolism probability. They share some risk factors but are used for different clinical questions.