CENTRAL PULMONARY-EMBOLISM WITH NORMAL VENTILATION PERFUSION SCAN-DIAGNOSIS BY NUCLEAR PULMONARY-ARTERY FLOW STUDIES

Pulmonary embolism, although uncommon in children, occurs in as many as 104 per 100,000 pediatric patients. Undiagnosed and untreated pulmonary embolism has a high mortality rate; thus, a high index of clinical suspicion and reliable diagnostic modalities are necessary to ensure prompt and accurate diagnosis. We report the case of a patient with severe central pulmonary embolism with a normal ventilation-perfusion scan. The embolus was identified by a nuclear pulmonary flow study using dynamic imaging, which obviated the need for contrast pulmonary angiography. The traditional ventilation-perfusion scan may appear normal despite severe central pulmonary embolism. In this situation, early dynamic imaging is necessary to detect severe obstruction of the central pulmonary arteries. This approach may obviate the need for contrast pulmonary angiography in hemodynamically stable patients.