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What is DICOM? Your medical imaging, explained

When you ask an imaging center for “your images,” what you get is DICOM. Here’s what that means — and why it matters for viewing and sharing your scans.

By UploMD · Updated July 2026

What DICOM actually is

DICOM (Digital Imaging and Communications in Medicine) is the universal standard for storing and exchanging medical images — MRI, CT, X-ray, ultrasound, mammography, and more. A DICOM file holds the actual image data plus metadata: which study it is, the body part, the settings, and patient identifiers. It’s what hospitals, imaging centers, and PACS systems all speak.

Why it isn’t just a JPEG

A JPEG or photo is a flat, compressed picture. A DICOM study carries full diagnostic data — often dozens or hundreds of image slices, high grayscale depth, and measurements a radiologist relies on. That richness is why DICOM needs a proper viewer, and why you can’t just double-click it like a photo.

Why your scans come on a CD or DVD

For years, the standard handoff has been a disc that bundles your DICOM study with a small built-in viewer. It works — but the viewers are frequently Windows-only, clunky, or refuse to launch, which is why so many people end up with a stack of discs they can’t open.

How to view DICOM files

You need a DICOM viewer. Options range from desktop software to web and phone apps. The simplest path for most people: UploMD opens your DICOM studies right on your phone — scroll the same slices your doctor sees, no CD and no desktop software. You can bring a viewable scan to any appointment or second opinion in a tap.

How to get your DICOM files

Ask the imaging center for “a copy of the images (DICOM), not just the report,” on CD, USB, or secure download. See our full guide to getting copies of your MRI or CT images.

Skip the chasing — let UploMD gather it for you

UploMD requests your records from every facility, keeps your real MRI, CT & X-ray viewable on your phone, and lets you share securely with family, your care team, or an ER. Free to start.

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Frequently asked questions

Is DICOM the same as my scan?

Yes — DICOM is the file format your actual scan (MRI, CT, X-ray) is stored in, along with metadata about the study. It’s different from the radiologist’s written report.

Can I open a DICOM file on a Mac or iPhone?

Not by default — DICOM needs a viewer. Bundled disc viewers are often Windows-only. UploMD opens DICOM studies directly on your phone.

How do I convert DICOM to JPEG or PDF?

A DICOM viewer can export a slice as an image, but converting loses the diagnostic depth doctors use. For a second opinion, share the original DICOM rather than a flattened JPEG.

Why is a DICOM study so large?

A single study can contain hundreds of high-resolution slices with full grayscale data, so files are much bigger than an ordinary photo.

This guide is general information, not legal or medical advice. Records-access rights and fees vary by state and facility; check with the specific provider for their process.