Hospitals hand scans over as DICOM files, usually on a CD or USB stick with a Windows viewer that will not run on a Mac, a Chromebook or a machine without a disc drive. This opens the files themselves: point it at the disc’s DICOM folder and it sorts the images into series, shows each one with a thumbnail, and lets you scroll through the slices, adjust the contrast, zoom and pan, and play a series or a cine loop.
It reads the compressed forms discs actually use - JPEG, JPEG lossless, JPEG-LS, JPEG 2000 and RLE - as well as uncompressed files, in greyscale and colour. Scans are about as private as files get, so they are read in the page and never sent anywhere. It is free to use, with no account and no upload limit, and it runs entirely in your browser: nothing is uploaded, and while the page stays open, a feature you have already used keeps working offline.
- How do I view an MRI or CT scan CD on a Mac or a computer without the disc's viewer?
- The program on the disc usually only runs on Windows, but the scans themselves are ordinary DICOM files. Insert the disc (or copy it to the computer first), press Choose a folder and pick the whole disc. The page reads the disc's index, DICOMDIR, and every scan, sorts them into series and opens the largest one. If it says the index lists more images than were found, choose the whole disc rather than one folder in it.
- Are my scans uploaded to be displayed?
- No. The files are read and decoded by the page on your own computer - dicom-parser reads the structure, and the compressed images are unpacked by codecs that run in the browser. Nothing about the scan, or the name and date of birth inside it, leaves your machine.
- Does the saved picture include my name?
- Not from this page. Save .png writes only the image itself: the name, date of birth and study details in the corners are drawn over the picture on screen, not into it - but a screenshot would catch them, which is what Hide patient details is for. Some scans, often ultrasound and scanned documents, have the name burned into the image itself by the machine that made them; the page says so when a file declares this, and that text stays in the saved picture.
- Why does a scan look too dark or washed out?
- A CT or MRI holds far more shades than a screen can show, so a viewer has to pick which range to spread across black to white. The file usually suggests one; Auto contrast uses it. Dragging on the image changes it, Full range shows everything at once, and the CT windows are the settings radiologists use for lung, bone, brain and soft tissue.
- Can it read every DICOM file?
- Most of what is on a patient disc, yes. The exceptions are 12-bit extended JPEG, an older compression now rarely used, and files with no DICOM header that are also big-endian. For those the details and tags still show, and the page says why the picture does not. Structured reports and radiotherapy plans have no image at all, so only their tags are shown.
- Can I use it for a diagnosis?
- No. It is for looking at your own images, not a medical device, and it has no measurement tools. Any question about what a scan shows is one for the radiologist’s report or your doctor.