How to open MRI files on your Mac
You got a hospital CD, USB stick, or download, and you're on a Mac — macOS Preview won't open it, Photos won't either, and Quick Look just shows a generic icon. That's because medical scans are DICOM files, not JPEGs. Here's the fastest way to see them: drag the folder into OpenMyScan in your browser. No install, no App Store, no upload — your files stay on your Mac.
Quick answer (3 steps)
- Copy the scan folder from your CD or USB onto your Desktop.
- Open
https://openmyscan.comin Safari or Chrome. - Drag the copied folder into the drop zone on the page. Wait a few seconds — your MRI appears.
Step 1 — Find the DICOM files
On a CD, insert the disc; Finder shows it in the sidebar. Inside you'll usually see a folder called DICOM, IMAGES, or the patient's name — sometimes with a small launcher app like StartViewer.app that only works on Windows. Ignore the .exe/.app launcher. You only need the DICOM folder itself. On a USB, open the drive; same story. On a downloaded ZIP, double-click it in Finder to extract before continuing.
Step 2 — Copy the folder to your Desktop
Drag the DICOM folder out of the CD/USB onto your Desktop. This matters because (a) CDs are slow, so reading every file over the disc drive takes minutes, and (b) some macOS versions sandbox browser reads from external volumes. Copy first, then open.
Step 3 — Open OpenMyScan
Go to https://openmyscan.com in Safari, Chrome, or Firefox. Any modern Mac browser works; no plugin, no Flash, nothing to install.
Step 4 — Drag the folder in
Drag the Desktop copy of the DICOM folder onto the drop zone labelled "Drop your scan folder here." The page will show a progress bar while it reads the files — 100–1000 slices is normal, and on a modern MacBook this takes 5–30 seconds.
Step 5 — Navigate the scan
Use the slider or your trackpad scroll gesture to move through slices. Adjust brightness / contrast from the sidebar. If the image looks too dark, tap "Easy-view" — for MRI this adjusts brightness and contrast so anatomy is easier to see. (For CT, keep Easy-view off unless you've been warned about the limitation — CT windowing is medically set.)
Common problems on Mac
- Finder shows a hybrid disc window with a Mac Installer
- Many hospital CDs have a Mac autorun wrapper that doesn't work on current macOS. Don't run it. Navigate the disc manually to the
DICOMfolder. - I see
DICOMDIRbut no.dcmfiles - That's a DICOM index file. OpenMyScan reads it automatically if it's in the same folder as the slice files.
- The CD is scratched or won't mount
- Ask the hospital for a replacement or a USB copy; most clinics can re-burn or re-download for free. In the meantime, some CDs will still read partially if you mount them on a Linux machine or a Windows laptop.
Frequently asked questions
Do I need an Apple Silicon or Intel-specific version?
No. Everything runs in your browser; the same page works on M1/M2/M3 Macs and older Intel ones.
Does this work offline?
Yes, after the first successful load. OpenMyScan caches in your browser, so you can use it on a plane or without WiFi as long as the page loaded once. Your files stay local either way.
Can I view my scan on my phone?
No. OpenMyScan needs a wider screen to show images alongside the series list — use a laptop, desktop, or tablet in landscape. Phone support is not planned.