Renal uptake on lung perfusion scintigraphy in a patient with primary pulmonary hypertension.

An 18-year-old woman presented with primary pulmonary hypertension (PPH) and was hospitalized because of hemoptysis and was referred to our department for a differential diagnosis pulmonary thromboembolism. Doppler ultrasonography of the lower extremities was normal. Echocardiography and cardiac catheterization showed right ventricular dilatation and increased pulmonary artery pressure without anatomic (intracardiac) shunt. The mean pulmonary arterial pressure was 110 mm Hg. Tc-99m MAA lung perfusion scans showed nonsegmental patchy defects. Extrapulmonary renal uptake and increased systemic deposition of radiotracer were seen in the MAA scintigraphy. It could be related to a functional intrapulmonary shunt resulting in increasing pressure in the pulmonary artery in PPH.