Metastatic pulmonary calcification in renal failure mimicking pulmonary embolism on lung scan

Metastatic pulmonary calcification (MPC) characterized by diffuse calcium deposition in the lungs is known to occur in patients with chronic renal failure. However, MPC with pulmonary artery calcification is uncommon and has only been detected in a few patients with severe disorders. A 48-year-old man with chronic renal failure had cough and progressive dyspnea. Ventilation-perfusion (V/Q) lung scans showed multiple large-sized mismatched V/Q defects in the left middle and lower zones of lungs, which was consistent with a high probability of pulmonary embolism (PE). The findings of pulmonary scintigraphy resulted from MPC with pulmonary artery calcification, revealed by simultaneous technetium-99m MDP scintigraphy, low-dose computed tomography, and high-resolution computed tomography (HRCT) of the chest.