Man With Progressive Dyspnea

Diagnosis 

Acute pulmonary embolism. The chest radiograph revealed enlargement of the right pulmonary trunk (long black arrow), oligemia distal to the engorged pulmonary trunk (area between white arrows), and compensatory hyperemia (area between short black arrows) (Westermark's sign1) (Figure 1). The contrast-enhanced chest CT demonstrated a filling defect in the right main pulmonary artery (black arrow), almost total occlusion (Figure 2). The non–contrast-enhanced CT demonstrated oligemia (area between white arrows) and compensatory hyperemia (area between black arrows) (Figure 3), compatible with the chest radiographic findings. The patient began receiving anticoagulation therapy, with a combination of heparin and warfarin, and his symptoms subsided gradually.

Up to two thirds of all ED patients have undetected pulmonary embolism.2 If not diagnosed early, it will cause critical morbidity and mortality. Westermark's sign is not usually observed on the chest radiography of acute pulmonary embolism. However, when it is detected, this lethal disease should be highly suspected. Chest CT could detect the embolus in the pulmonary artery and uneven distribution of vascularity. These CT findings confirm the diagnosis of pulmonary embolism.