Developing a COMputerised Bone Age Tool

The Greulich and Pyle technique (G\&P) is that most commonly used to assess bone age in children, particularly in the context of suspected skeletal dysplasia. However it has been shown not to be applicable to children of Asian and African ethnicity and may not be applicable to United Kingdom (UK) Caucasian children, who are now relatively more mature and larger than children of the mid 1930's (when G\&P was developed). It is generally agreed that updated standards are required for rapid and reliable bone age assessment. The development of such standards requires irradiation of normal children. To do this ethically, radiation exposure must be kept as low as possible. Two recent studies suggest that bone age assessment can be reliably achieved from dual-energy x-ray absorptiometry (DXA) scans. As far as the investigators are aware, the Tanner \& Whitehouse (TW3) method, which is preferred by some (e.g. endocrinologists and nutritionists), has not been assessed from dual-energy x-ray absorptiometry (DXA) scans - although not the main focus of this study, because of its popularity amongst certain specialties, the investigators shall be assessing the TW3 method also. Modern techniques should not only be available as textbooks, but should also be available in digital (on-line) format and where possible integrated with hospital PACS systems. The investigators believe that their team has the required experience and expertise to successfully carry out such a project. Before conducting the required large cross-sectional study, the investigators must first confirm that DXA can in fact replace radiographs for bone age assessment in children; which is the objective of this current study.