Metastatic pulmonary calcification: ‘crazy paving’ pattern

High-resolution CT scan is sensitive and specific as it is able to depict small amounts of calcification seen compared with conventional chest X-ray. 1 Upper lobes are mainly involved (as in this patient) because of the high ventilation-perfusion ratio, which results in lower capillary pCO2 and a higher pH compared with the lower lobes. 2 It is important to know that despite the term 'metastatic' being used, it is a relatively benign condition with a good long-term prognosis.