Developing a COMputerised Bone Age Tool
Condition: Bone Diseases, Developmental
MeSH terms: Bone Diseases; Bone Diseases, Developmental
Study type: Interventional

Summary: 
      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.
    

Detailed description: 
      This is a small prospective feasibility study to be performed over a 12-month period.

      Children booked for a left hand radiograph for bone age assessment (either in isolation or as
      part of a dysplasia skeletal survey) will be recruited. This will require a purposive sample
      of 2 males and 2 females from each of the following 5 age groups (<5; 5 to 7; 8 to 10; 11 to
      13; 14 to 16 years). There will therefore be a total of 20 children (10 males). Because the
      aim of the study is to compare results of DXA with those of radiographs in corresponding
      children, ethnicity of individual children will not be an issue; in other words the
      investigators are assessing the reliability of DXA not the reliability of G&P or TW3.

      Relevant clinicians will identify patients from appropriate clinics at Sheffield Children's
      Hospital. Only patients having a left hand radiograph for bone age assessment on the basis of
      clinical need will be approached. Age appropriate information sheets will be given to them,
      and the study briefly discussed. When they arrive at the Radiology Department for their left
      hand radiograph, an appropriately certified radiographer will seek informed consent and
      provided the left hand radiograph is actually performed, they will then also have DXA of the
      left hand and those over 6 years old will be asked to complete a brief questionnaire.

      Researcher 1 will anonymise hand radiographs and DXA scans, such that corresponding patient
      images are not identifiable. Researcher 1 will also document patient age and sex, ethnicity
      and body weight and height (no other clinical information is required for the purposes of
      this feasibility study).

      Researchers 2, 3 and 4 will independently assess all images using both G&P and TW3. All
      observers will interpret a random selection of half the images (again independently) on a
      second occasion at least 2 months after the first; on both occasions the Images will be
      interpreted in random and varied order. Images will be read in two batches of 10 radiographs
      and 10 (non-corresponding) DXA scans for the first read and 5 radiographs and 5
      (non-corresponding) DXA scans for the second read.

      Statistical analysis is largely irrelevant for this small feasibility study. The
      investigators' main aim is to assess whether or not G&P and TW3 can be reliably assessed from
      hand DXA images.

      The concordance between 1) independent readings of the three observers for radiographs and
      for DXA (i.e. comparing modalities) and 2) individual observers for both occasions (i.e.
      comparing observer reliability for each modality) will be evaluated using interclass and
      intraclass correlation coefficients. The investigators will calculate the mean and standard
      deviation of the differences between DXA and radiographs and between observers.

      Statistical analyses will be performed using the Statistical Package for the Social Sciences,
      version 21 for Mac (SPSS, Chicago, IL).
    

Intervention name(s): Left hand DXA
Intervention type(s): Radiation
Intervention description(s): All recruited children will have a left hand DXA scan which will be anonymised and from which 3 observers will independently assess bone age according to Greulich and Pyle and TW3 methods on 2 separate occasions at least 4 weeks apart.
Radiographs and DXA will be read in random and varied order.
Other intervention name(s): DXA of left hand and wrist
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Diagnostic
Keywords: Bone age; Greulich & Pyle; TW3; Radiography; Dual energy x-ray absorptiometry