Each medical image is stored in standard DICOM format. In addition to the pixel data (image) the DICOM header stores meta-data in fields that are known as “tags” which contain a large amount of information including patient identifiable information. In order to preserve the confidentiality of the patients, all header data is de-identified following the guidelines provided by DICOM Supplement 142 Annex A1. This supplement is an international standard for de-identification of data in medical image files.
In total 222 DICOM tags are “nulled” (removed or obfuscated according to DICOM specifications), in some instances obfuscating is necessary in order to preserve the integrity of the DICOM file. A full list of all tags nulled can be found here.
DICOM tag | Description |
---|---|
0008,0020 | StudyDate |
0008,0021 | SeriesDate |
0008,0022 | AcquisitionDate |
0008,0023 | ContentDate |
0008,0050 | AccessionNumber |
0008,0090 | ReferringPhysicianName |
0008,1010 | StationName |
0008,1070 | OperatorsName |
0020,0010 | StudyID |
0020,4000 | ImageComments |
0040,0244 | PerformedProcedureStepStartDate |
0018,700a | DetectorID |
0018,700c | DateOfLastDetectorCalibration |
0400,0100 | Digital Signature UID |
0020,000E | SeriesInstanceUID |
0040,A124 | UID |
0000,1000 | Affected SOP Instance UID |
0020,9161 | Concatenation UID |
0008,010D | Context Group Extension Creator UID |
0008,9123 | Creator Version UID |
0018,1002 | Device UID |
0020,9164 | Dimension Organization UID |
300A,0013 | Dose Reference UID |
0070,031A | Fiducial UID |
0020,0052 | Frame Of Reference UID |
0008,0014 | Instance Creator UID |
0008,3010 | Irradiation Event UID |
0028,1214 | Large Palette Color Lookup Table UID |
0002,0003 | Media Storage SOP Instance UID |
0028,1199 | Palette Color Lookup Table UID |
3006,0024 | Referenced Frame Of Reference UID |
0040,4023 | Referenced General Purpose Scheduled Procedure Step Transaction UID |
0008,1155 | Referenced SOP Instance UID |
0004,1511 | Referenced SOP Instance UID In File |
3006,00C2 | Related Frame Of Reference UID |
0000,1001 | Requested SOP Instance UID |
0008,0018 | SOP Instance UID |
0088,0140 | Storage Media File Set UID |
0020,000D | Study Instance UID |
0020,0200 | Synchronization Frame Of Reference UID |
0040,DB0D | Template Extension Creator UID |
0040,DB0C | Template Extension Organization UID |
0008,1195 | Transaction UID |