Low dose Chest CT scan is the standard for lung cancer in the health check center in China. Quantitative computed tomography (QCT) is utilizing the CT raw data to measure the bone mineral density (BMD), the visceral fat (VAT) and liver fat content in human, which can be widely used in the diagnosis of osteoporosis, the assessment of obesity and liver steatosis. In this nationwide multi center study the investigators combine the low dose chest CT scan data with QCT technology, to measure the BMD of spine, VAT and liver fat in the health check subjects. This study is to evaluate the performance of QCT in the health check field, and further to evaluate the prevalence of osteoporosis, obesity and liver steatosis in health check population across China.
