In last week’s post we talked about how BoneStation automatically generates an assessment. A couple of sample sets of rules were provided for BMD. This week we’ll extend those rules to include fractures.
As a review, BoneStation’s rules engine takes inputs from three sources: BMD scan data, patient data, and online questionnaire. It generates output, which is an assessment.
When adding fractures an additional input is needed: the VFA scan. More specifically, vertebral fractures as noted by the reading physician (using BoneStation) are used.
Here is an updated diagram depicting the rules engine.

Before we show the updated rules for VFA, it is important to note:
- In BoneStation there are four choices for indicating the presence of a fracture on VFA: Yes, Maybe, No, and Indeterminate.
- Fractures may be indicated on the questionnaire – as patient reported. See sample questionnaires below for examples of how fractures may appear in questionnaire form.
Only the rules for normal bone density (T-score ≥1.0) are displayed below. Showing all the assessment categories will be too lengthy. The rules for the other categories would be similar.

The original BMD rules used these inputs:
- Age
- T-score
- Z-score
For fractures we added:
- QN Fx = Fracture indicated on the questionnaire
- VFA Performed = Yes/No – if a VFA was performed
- VFA FX = Fracture indicated on VFA
The sample rules above represent one way to automate the assessment of bone density scans. There are many variations.
BoneStation’s rules engine is very flexible. Rules, questionnaire, and output (assessment) text may all be customized.
Here are some sample questionnaires.