MRI and CT findings of metastatic pulmonary calcification.

Metastatic pulmonary calcification is a consequence of calcium deposition in the normal pulmonary parenchyma, secondary to abnormal calcium metabolism. The most characteristic radiological manifestation is poorly defined nodular opacities that are mainly seen in the upper lung zone. The aim of this report is to describe the CT and MRI findings observed in two patients with metastatic pulmonary calcification. The disease may present in CT as consolidations with calcification, and with a high lesion/muscle signal intensity ratio on T(1) weighted imaging without contrast in MRI. The high signal on T(1) weighted imaging probably occurs because the low calcium concentration of the lesion changes the surface effects of diamagnetic calcium particles, causing T(1) shortening of water protons. MRI is a good option for characterising calcium accumulation caused by a metabolic disorder.