PetaMask for DICOM

PetaMask for DICOM is a tool that allows you to black out "areas you don't want to show" in DICOM images (CT, MRI, X-ray, ultrasound, etc.), erase or replace metadata tags such as patient names and IDs, and save the files in DICOM format.

It is a sister tool to "PetaMask" for images and PDFs. Since you can edit while keeping the DICOM format, image quality and measurement information (such as pixel spacing) remain unchanged. It also supports color images and ultrasound videos (cine loops). One tool handles everything from conference slide preparation to central adjudication in clinical trials and research.

How to Use (Just press ① → ④ on the screen. Blue speech bubbles will guide you)

① Open — Drag and drop .dcm files. With "📁 Folder," you can load an entire examination folder at once (switch files in the list on the left)

② Black out the image — Drag over the image to black out burned-in names and other information. When loading a folder, you only need to black out files containing personal information

③ Erase personal information tags — Erase/replace patient names, IDs, dates of birth, examination dates, facility names, etc. Regenerate UIDs and delete private tags and overlays. When loading a folder, pressing once applies to all files. You can check the results immediately in the list on the right side of the screen

④ Save — Three formats: DICOM/JPG/A4 PDF. When loading a folder, use "📦 All Files ZIP" to save all files with tags erased and blacked out together in a ZIP file (tag erasure is applied automatically even if you forget to press it). JPG and PDF can be used directly for slide insertion or attachment to submission documents such as JUDY and Format 12 (image only, no tag information included)

Beginners can practice with the built-in sample (fictional data)
Continuous images (multi-frame/ultrasound cine) are blacked out in bulk for all frames
Japanese patient names (half-width katakana + kanji) are displayed and erased correctly
Black-out is burned into pixels. It cannot be removed later
Supported Formats

Uncompressed (implicit/explicit little-endian), RLE, JPEG Lossless, JPEG Baseline
Grayscale (MONOCHROME1/2, 8/16-bit, signed support) / Color (RGB, YBR, palette color)
Multi-frame / Batch folder loading (ZIP save)
Output is uncompressed DICOM (can be opened with general viewers. Color is output as RGB)
※JPEG 2000, JPEG-LS, and MPEG video formats are not supported (a message will be displayed when loading)

Peace of Mind Points

Completely offline — Images never leave your PC
No installation required — Just open in a browser (Windows / Mac / Tablet)
Portable — Save the HTML file (one file) with "📥 Save Main Body" in ⓘ Information, and you can use it with a double-click on a PC without internet
You can check the erased tags in the list on the right side of the screen before saving
Important Notes

You must personally verify that there are no missed black-outs or unerased tags
This tool provides "processing" for removing and replacing personal information. Whether it qualifies as "anonymized processed information" or "pseudonymized processed information" under law is determined by operations such as the presence of a correspondence table, so judgment should follow your facility's or requester's regulations
When submitting to clinical trials or research, follow your facility's or requester's regulations/procedures
This tool is not a medical device (no warranty / use at your own risk / MIT License)
Included libraries: dcmjs (MIT) / jpeg-lossless-decoder-js (MIT)