Answer
It checks for nephrocalcinosis, a build-up of mineral deposits within the kidneys.
Sources for this answer
- CRYSVITA 10 mg solution for injection in pre-filled syringe — Current selected SmPCemc · Summary of Product Characteristics
- Crysvita solution for subcutaneous injection — Current selected SmPCemc · Summary of Product Characteristics
General medicine information. Follow the instructions for your own medicine and speak to a pharmacist or clinician about your individual circumstances.