Bone mineral content (BMC)was measured by the cortical thickness of clavicle from the chest radiographs of 1200 normal adults and 4000 patients The combined cortical thickness (CCT) of the clavical was tabulated according to sex, age and health.

• 对1200例正常人及4000例患者的标准后前位胸片进行锁骨皮质厚度测量。