Why won't an MRI image open in a regular viewer?

DICOM allocates 12-16 bits per pixel (4096-65,536 shades of gray), while JPG has 8 bits, that is 256. A regular viewer can't apply window/level - the window settings a doctor uses to pull bones or soft tissues out of that range. So the file looks black or washed out, even though the data inside is intact.

What is DICOMDIR and why won't it open?

DICOMDIR is not an image but the disc's table of contents: a list of which studies and series are stored where. You need to open the files from the DICOM folder next to it. Mobile viewers often stumble on DICOMDIR itself - import the whole folder.

The files on the disc have no extension - is that normal?

Yes. DICOM is often written with no extension at all or with the .dcm extension. The format is recognized not by the name but by the signature inside the file, so such files open here as they are.

What happens to my file?

The file is processed on the server and automatically deleted after 24 hours. Personal data from DICOM tags (name, date of birth) is not shown and not stored.

Will the AI make a diagnosis from the image?

No, and that's a deliberate decision. The free description tells you what is shown: modality, body area, projection, visible structures. A diagnosis from one slice out of several hundred would be dishonest - pathology is looked for across the whole series. That's what the full study report is for.

Free · no installation

Open DICOM online

The disc from the clinic won't open, but you need the image right now. Drag the file here - it opens in the browser exactly as the scanner intended and downloads as a regular PNG you can send to a doctor. Up to 5 images free, no software to install.

Drag a DICOM file here

or click to choose. .dcm files, files without an extension from an MRI disc, as well as JPG and PNG.

Why DICOM won't open on its own

DICOM (Digital Imaging and Communications in Medicine) is not just a picture - it's a picture together with medical metadata: modality, study date, scanner model, slice thickness, acquisition parameters. One slice is one file, so a spine MRI is 100-500 files, and a CT can be over a thousand.

A regular viewer shows a black rectangle not because the file is corrupted. DICOM allocates 12-16 bits per pixel - from 4096 to 65,536 shades of gray, while JPG has 256. A doctor "adjusts the window" (window/level), stretching the needed part of the range across the whole screen: one window shows bones, another soft tissues, a third the lungs. A photo viewer knows nothing about this and shows the data as is.

Here window/level is applied automatically - from the WindowCenter and WindowWidth tags written by the scanner itself. If the file has none, the contrast is derived from the slice histogram.

What to do with the opened image

The downloaded PNG is easy to send to a doctor in a messenger or attach to a telemedicine consultation: it opens on any device without special software. But keep in mind that PNG is a "flattened" copy: 256 shades instead of tens of thousands, and you can't "adjust the window" on it. Keep the original disc.

If you need to understand rather than just look - what exactly is in the images and whether anything is off - that's work across the whole series, not a single frame. Upload the full study: the AI reads the slices, marks findings with arrows on the images, compares them with the norm and builds a PDF report.

Frequently asked questions

Why won't an MRI image open in a regular viewer?: DICOM allocates 12-16 bits per pixel (4096-65,536 shades of gray), while JPG has 8 bits, that is 256. A regular viewer can't apply window/level - the window settings a doctor uses to pull bones or soft tissues out of that range. So the file looks black or washed out, even though the data inside is intact.
What is DICOMDIR and why won't it open?: DICOMDIR is not an image but the disc's table of contents: a list of which studies and series are stored where. You need to open the files from the DICOM folder next to it. Mobile viewers often stumble on DICOMDIR itself - import the whole folder.
The files on the disc have no extension - is that normal?: Yes. DICOM is often written with no extension at all or with the .dcm extension. The format is recognized not by the name but by the signature inside the file, so such files open here as they are.
What happens to my file?: The file is processed on the server and automatically deleted after 24 hours. Personal data from DICOM tags (name, date of birth) is not shown and not stored.
Will the AI make a diagnosis from the image?: No, and that's a deliberate decision. The free description tells you what is shown: modality, body area, projection, visible structures. A diagnosis from one slice out of several hundred would be dishonest - pathology is looked for across the whole series. That's what the full study report is for.

This service is not a medical device and does not make diagnoses. The image description is for reference only; interpreting a radiology study is the job of a radiologist.