Free DICOM anonymisation
Free DICOM anonymisation, in the browser, no upload.
Remove patient data from DICOM files to the DICOM standard PS3.15. Processing runs entirely in the browser; the images never leave your computer.
- Free, no account
- No upload
- To DICOM PS3.15
The tool edits the header, not the pixels. Burned-in annotations remain; series where that is likely are detected and flagged. Whether the result is sufficient for your purpose is for you to check.
Partners
Who it is for
Who has to anonymise DICOM files?
For single files on your own computer this tool is enough. If you regularly pass on whole studies, anonymise them straight from Unomed PACS instead.
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Teaching and training
Build case collections for lectures, courses and exams without patient data travelling along. Age and sex are kept so the case stays clinically readable.
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Doctors
Share a single image for a colleague's second opinion: anonymised, without a detour via IT and without the file being uploaded anywhere.
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Research and studies
Prepare image data for analysis. The intervals between examinations are preserved, the absolute date is not, so follow-up analyses remain possible.
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Radiology practices
Departments that regularly release image data need a single consistent route and a record of who anonymised what, and when.
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Publications and journals
Publishers require anonymised image data. What gets checked is the header, and it holds more than is visible when looking at the image.
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Data protection officers
See what a DICOM file actually reveals before it leaves the building, and decide which profile applies.
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Referring institutions
Whoever passes images on to third parties is liable for what travels in the header. A fixed profile takes that decision out of the individual case.
Why anonymise DICOM?
Anonymise DICOM, free and without upload.
Unomed's free tool removes patient data from DICOM files entirely in the browser. There is no server receiving the images; once the page has loaded it works without a network connection. No registration, no installation, no size limit other than the browser's memory.
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Why overwriting the patient name is not enough
Identifying information sits in a DICOM file on three levels. In the header: the standard keeps its own table of 621 attributes there, from the referring physician through the institution to the device serial number. In the identifiers that point back to the source system and therefore have to be reissued without breaking the study's structure. And outside the designated fields: burned into the pixels, in vendors' private fields, in free text and structured reports.
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What the tool does
It applies the Basic Application Level Confidentiality Profile from DICOM PS3.15. Age, sex, height and weight are kept, otherwise an image is clinically worthless for second opinions and teaching. Dates are shifted by a random amount that stays constant for the whole run: the intervals between examinations remain, the absolute date is gone. All private tags are removed, all identifiers are consistently reissued, and the file is marked as anonymised according to the standard.
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What the tool does not do
It edits the header, not the pixels. Burned-in annotations remain, and a head CT is not defaced. Series where burned-in data is likely (ultrasound, secondary capture or a set Burned In Annotation) are detected and excluded from the result by default. They can be added individually, with a visible warning. An ultrasound image with a name in the picture, silently passed through, renders the whole anonymisation worthless without anyone noticing.
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Anonymous or pseudonymous? The difference matters
The two terms are often used interchangeably but differ clearly in law. What matters is not what happens to the file but whether a link back to the original is kept. If a list is kept of which original study belongs to which pseudonym, it is pseudonymisation, and under the Swiss Data Protection Act the data remains personal data. This tool keeps no such list; whether the result stays anonymous depends on whether someone records the link elsewhere.
From the tool to PACS
When you need more than single files
If you regularly pass on whole anonymised studies, a server-side solution serves you better: no transfer of large data volumes, a traceable record of who anonymised what and when, and the option to forward the result directly.
| Feature | Free browser tool | Unomed PACS |
|---|---|---|
| Anonymise header data | Yes | Yes |
| Series selection | Yes | Yes |
| Whole studies instead of single files | No | Yes |
| Share with colleagues | No | Yes |
| Traceable history | No | Yes |
| Forward straight from PACS | No | Yes |
| Price | Free | from CHF 99 per month |
Frequently asked questions about DICOM anonymisation
Are my DICOM files uploaded?
No. Processing takes place entirely in the browser. Once the page has loaded you can disconnect from the network and still use it.
Which data is removed?
The attributes of the Basic Application Level Confidentiality Profile under DICOM PS3.15, 621 entries, including name, patient ID, date of birth, referrer, institution and device identifiers. Plus all private tags, and all identifiers are consistently reissued.
Is burned-in patient data removed as well?
No. The tool edits the header, not the pixels. Series where burned-in data is likely are detected and clearly flagged. Checking them is up to you.
Do the images stay linked afterwards?
Yes. All files of one run share the identifier mapping, the date shift and the pseudonym. The assignment of study, series and single image is preserved.
Do I have to register or install anything?
No. The tool runs directly in the browser, without installation, without registration and free of charge.
Is the result anonymous or pseudonymous?
The tool keeps no list of which original study belongs to which pseudonym. As long as nobody records that link elsewhere, the result is anonymous. If such a list is kept, the data remains personal data under the Swiss Data Protection Act.
And if I have to anonymise whole studies?
Server-side processing suits that better. In Unomed PACS a study can be exported directly as an anonymised copy, without downloading the data first. Talk to us.
Next step
Anonymise straight from PACS.
Whole studies instead of single files, with a traceable history. Unomed Cloud PACS from CHF 99 per month, no setup fee. Free in the basic version.