Supported Knee MRI & X-ray File Formats
Our free knee MRI viewer opens DICOM files from every major scanner, plus ZIP and TAR archives, NIfTI exports, and 8-, 12-, and 16-bit pixel data. If your scan came on a CD or USB, you can drop the whole folder or ZIP into the viewer — nothing leaves your browser.
Archive formats
If your scan came as one big compressed file, drop it directly into the viewer — we unpack it in your browser.
- ZIP — the most common format on hospital CDs and patient-portal downloads
- TAR — common for research datasets
- .tar.gz and .tgz — TAR + GZIP compressed
DICOM transfer syntaxes
The technical format used to encode pixel data inside a DICOM file. Our viewer decodes every common transfer syntax used by clinical scanners.
- Implicit VR Little Endian (1.2.840.10008.1.2)
- Explicit VR Little Endian (1.2.840.10008.1.2.1)
- JPEG Lossless (1.2.840.10008.1.2.4.70)
- JPEG Extended 12-bit (used by i-CAT dental CBCT)
- RLE Lossless
- 8-bit, 12-bit, and 16-bit pixel data
- MONOCHROME1 and MONOCHROME2 photometric interpretations
NIfTI (research / converted scans)
NIfTI (Neuroimaging Informatics Technology Initiative) is the format used by most research and post-processing tools. If you ran your scan through a pipeline like FreeSurfer or fastMRI, you likely have a NIfTI file.
- .nii — uncompressed NIfTI volume
- .nii.gz — GZIP-compressed NIfTI (most common)
Compatibility at a glance
| Format | Opens in viewer | 3D / MPR | Notes |
|---|---|---|---|
| DICOM (.dcm / .dicom / .ima) | Yes | Yes when volumetric | Native format |
| ZIP / TAR / .tar.gz | Yes | Yes if contents are DICOM | Unpacked in your browser |
| NIfTI (.nii / .nii.gz) | Yes | Yes for volumes | Research / converted scans |
DICOM (.dcm / .dicom / .ima)
Opens: Yes · 3D: when compatible · Native format
ZIP / TAR / .tar.gz
Opens: Yes · 3D: if DICOM inside · Unpacked locally
NIfTI (.nii / .nii.gz)
Opens: Yes · 3D: Yes · Research format
Privacy and 3D viewing guides
When the viewer can't open your file
Encrypted CDs (rare, mostly older European systems), multi-volume archives split across several discs, and proprietary vendor formats outside the supported list are the main exceptions. For encrypted CDs, your hospital's release form can request an unencrypted copy. For multi-volume archives, combine into a single ZIP before dropping.
Frequently Asked Questions
Does the viewer open .nii.gz files?
Yes. Drop the .nii.gz file directly — the viewer decompresses and parses it in your browser.
Can I drop a folder or only a ZIP?
Both work. Drop the entire DICOM folder from your CD, or zip it first — either way the viewer organizes the slices automatically.
Why won't my hospital DVD open in the browser?
The DVD's built-in viewer is usually a Windows-only executable. Copy the DICOM folder from the disc to your computer, then drop it into our viewer — the underlying DICOM files work the same everywhere.
What's the largest scan size I can upload?
In practice, knee MRI studies are typically 50–500 MB. The viewer handles multi-gigabyte volumes provided your device has enough RAM (8 GB+ recommended for very large series).
Does the viewer handle multi-volume DICOM archives?
Yes — multiple series within one folder are detected and grouped automatically. If your study spans multiple ZIPs, drop them one at a time and the viewer merges them in-session.
Can knee scans support MPR or 3D rendering?
DICOM series with enough slices can support MPR and 3D views. Single-image X-rays remain 2D, while the 3D joint render works best on compatible knee MRI series with suitable slice thickness and spacing.