September 24, 2026 · 4 min
What is a DICOM file and how do you open it?
DICOM is the standard format of medical images. Learn what .dcm files and DICOMDIR are, and how to open them on Mac, Windows or phone.
DICOM in one sentence
DICOM is the universal format used by scanners and MRI machines. Each file holds one image (a slice) plus information such as the date, the type of exam and the position in the body.
What you find on a CD
A DICOMDIR index file, folders with oddly named files (often without extension), and sometimes a Windows viewer. The images are the files inside the folders.
How to open them
On a computer, copy the whole CD folder or make a ZIP of it, then import it into a browser viewer like scans.me. It works on Mac, Windows, Linux, tablet and phone.
Are my original files modified?
No. scans.me keeps the original bytes of each file as they are. You can export them at any time.
Store, view and share your medical images.
Try scans.meThis article is for information only and does not replace advice from a health professional.