Reversible mapping (key-vault)
Map Patient IDs to pseudonyms with reversible AES-256 encryption.
Problem
You’re de-identifying DICOM studies for a clinical trial, but the trial sponsor requires the ability to re-identify patients later if a clinically significant incidental finding is discovered. Simply replacing Patient IDs with ANON is irreversible — there’s no way to map back. You need a reversible pseudonymization system: replace real Patient IDs with anonymous pseudonyms, store the mapping in an encrypted vault, and provide a way to revert (decrypt) the pseudonyms back to the original IDs when authorized.
Steps
Pseudonymize
-
Open your DICOM file (⌘O) and switch to Edit mode (⌘3).
-
Set a known Patient ID — double-click the Patient ID tag (0010,0020), enter a value like
PID-12345, and save. -
Switch to Anon mode (⌘2).
-
Enable reversible pseudonymization — toggle the Reversible Pseudonymization switch to ON. This tells the anonymization engine to encrypt (not destroy) the original Patient ID and store the mapping.
-
Apply — click the Apply button.
-
Verify the pseudonym — switch back to Edit mode (⌘3) and check the Patient ID. It should now display
ANON-9999(the fixed demo pseudonym placeholder).
Re-identify
-
Switch to Anon mode (⌘2).
-
Click “Revert Demographics” — this button decrypts the stored mapping and restores the original Patient ID.
-
Verify — switch to Edit mode (⌘3). The Patient ID should be back to
PID-12345.
Expected Result
- After pseudonymization: Patient ID is
ANON-9999. - After revert: Patient ID is restored to its original value (
PID-12345). - The mapping is stored in-memory during the session. In a production deployment, the encryption key would be stored in a secure vault (hardware security module or key management service).
- Non-demographic tags (modality, pixel data, study descriptors) are unaffected.