What the standard acquisition looks like
The standard examination for bone age is a single posteroanterior (PA) radiograph of the left hand and wrist. The patient places the hand flat on the detector, palm down, fingers slightly separated and extended, with the thumb in a natural position at roughly 30 degrees.
The beam is usually centred on the third metacarpal head. Coverage matters: the field should start at the fingertips and include the wrist joint and the distal radius and ulna. If the wrist is excluded, some of the most informative maturity indicators are lost.
Common mistakes
The problems below degrade assessment for radiologist and AI model alike. Some of them make the result wrong without any visible sign in the image — which is why they must be caught at acquisition:
- Wrist outside the field of view or cropped
- Overlapping, flexed or partly clenched fingers
- Hand rotated obliquely, causing bones to superimpose
- Motion blur, especially in young children
- Wrong exposure: too dark or too bright, with lost contrast
- Burned-in patient details, arrows or markers covering bony structures
- Obstructing material such as casts, splints, rings or bracelets
- Radiographing the right hand by mistake and reporting it against the left-hand standard
Preparing the image for AI analysis
You can upload DICOM (.dcm) files as well as JPG, PNG and BMP images. Prefer DICOM where possible: it carries the original greyscale data with no loss compared with a screenshot.
If you must photograph a screen, shoot square-on, avoid reflections, and keep the whole hand in frame. Do not leave the bone age report or patient name inside the frame — it shares personal data unnecessarily, and text overlaid on the image can distract the model.
Radiation and paediatric patients
A hand-wrist radiograph is one of the lowest-dose examinations in medical imaging, and the hand is far from radiosensitive organs. Nonetheless the ALARA principle applies in children: avoiding an unnecessary repeat acquisition is the single most effective dose reduction.
That is precisely why positioning matters so much — a failed acquisition usually means a second acquisition, and therefore a second dose.