This paper analyses the geometry of intra-thoracic organs from CT scans performed on 20 children aged from 4 months to 16 years. The aim is to find the most reliable measurements to characterize the growth of heart and lungs from CT data. Standard measurements available on chest radiographies are compared with original measurements only available on CT scans. These measurements should characterize growth of organs as well as changes in their position relative to the thorax. Measurements were considered as functions of age. Quadratic regression models were fitted to the data. Goodness of fit of the models was then evaluated. Positions of organs relative to thorax have a high variability compared with their changes with age. Heart and lung lengths and volumes as well as thorax diameter well fit the models of growth. It could be interesting to study these measurements with a larger sample size in order to define growth standards. 3D reconstruction, intra-thoracic organs, child, growth standards, lung, heart
