Source: https://openmyscan.com/en/guides/how-to-open-dicom-zip-files Guide G–08 · Opening # How to open a downloaded MRI or CT ZIP file Patient portals often deliver an MRI or CT as a ZIP archive. The ZIP is a package containing your files, not a different scan format. Extract the complete package on your computer, keep its folders together, then open the image folder in a DICOM viewer. Gabriel Theis Founder, OpenMyScan 5 min read Updated October 26, 2026 Beginner ## How do I open a DICOM ZIP file? Wait for the download to finish. [On Mac](https://openmyscan.com/en/guides/how-to-open-mri-files-on-mac), double-click the ZIP in Finder; [on Windows](https://openmyscan.com/en/guides/how-to-open-dicom-files-on-windows), right-click it and choose Extract All. Open the extracted parent folder in a DICOM viewer, keeping DICOMDIR and the image folders together. If the ZIP is password protected, get the password from the sender and extract it locally first. Extracting first is the most predictable route, especially for large or password-protected archives. OpenMyScan can also read some ordinary ZIP archives directly, but it applies archive safety and size limits. If direct import fails, extract the download on your computer and select the resulting folder. ## Step 1 — Finish downloading the archive Use the imaging center's download instructions and save the ZIP to a folder on your own computer. Wait for the download to finish before opening it. A browser's partial-download file or a portal page saved as HTML is not the study archive. If the portal offers both “report” and “images,” choose the images or DICOM export when you want the scan. A report PDF contains the radiologist's written findings; it does not contain the complete scrollable image study. ## Step 2 — Extract the complete ZIP ### On a Mac Find the downloaded ZIP in Finder, often in Downloads. Double-click it to create an extracted folder. If extraction reports an error or asks for a password that you do not have, follow the sender's instructions or request a fresh download. Keep the original ZIP until you have checked the extracted copy. ### On Windows In File Explorer, right-click the ZIP and choose **Extract All**. Choose a destination you can find again and wait until extraction finishes. Browsing a ZIP as if it were an ordinary folder is not the same as extracting all its files. Keep the folders and filenames as supplied. If `DICOMDIR` sits beside `DICOM` or `IMAGES`, keep them together. Image files may have no extension; do not add `.jpg` or rename them to make them open. ## Step 3 — Open the extracted study folder Open the [DICOM viewer](https://openmyscan.com/en/dicom-viewer) on a desktop or laptop. Drop the extracted parent folder onto the page or use the folder picker. Your scan files are read on your device. You do not need an online unzip service or the launcher supplied inside the archive. Choose a series and scroll through the slices. Check the date and series list before deleting any duplicate download. Loading one series does not prove the export contains every series from the examination. ## What if the ZIP does not open or has no images? **The archive asks for a password** Ask the imaging center or sender for the password and its extraction instructions. Do not assume the browser viewer can unlock encrypted archives. **Extraction fails or ends partway through** Check that the download completed and that your computer has space for the extracted files. Download a fresh copy; if the same error repeats, ask the sender to replace it. **There is another ZIP inside** Extract that archive too, following the sender's instructions, and keep the resulting study folder intact. **I only see a PDF, a link, or DICOMDIR** A report or index alone is not the images. Ask for the complete DICOM export. Our [DICOMDIR guide](https://openmyscan.com/en/guides/what-is-dicomdir-and-how-to-open-it) explains which files belong together. **The folder opens but one series fails** Use the [troubleshooting guide](https://openmyscan.com/en/guides/dicom-files-wont-open) to distinguish a missing file from a display or compatibility problem. ## How should I keep or send the original ZIP? Store the original archive as a backup on a device or service you trust. ZIP packaging alone does not guarantee encryption, and DICOM files can contain patient details. When another doctor needs your study, follow the receiving clinic's transfer instructions and send the complete DICOM files rather than a few JPG exports. See [how to send an MRI to another doctor](https://openmyscan.com/en/guides/how-to-send-mri-to-another-doctor). // open your scan Ready Open your scan right now OpenMyScan runs in your browser. Your files stay on your computer while you review them. [Open viewer](https://openmyscan.com/en/dicom-viewer) ## Common questions ### Can I drop a ZIP straight into OpenMyScan? Some ordinary ZIP archives can be imported directly, subject to safety and size limits. Extracting the complete ZIP locally and choosing the resulting folder is the fallback if direct import fails. Encrypted archives should be extracted locally with the sender's instructions. ### Will extracting the ZIP change my scan? Extraction unpacks the files rather than converting the images. Keep the original archive and its folder structure, and check that extraction completed without errors. ### Can I email JPGs instead of the ZIP? JPG exports can illustrate selected images but do not replace the complete DICOM study. Ask the receiving clinician how to transfer the original files. → try it now ## Open *your* scan Your original scan files are read on your device without a scan upload. Local previews and settings can persist after closing the tab; clear this site’s browser data to remove them completely. [Open viewer](https://openmyscan.com/en/dicom-viewer) [Browse all guides](https://openmyscan.com/en/guides) ## Keep reading [All 14 guides →](https://openmyscan.com/en/guides) [G–06 · Opening What is DICOMDIR, and how do I open it? DICOMDIR is an index, not your scan images. Learn which folders to keep, how to open the complete study, and what to do when images are missing. Read guide](https://openmyscan.com/en/guides/what-is-dicomdir-and-how-to-open-it) [G–07 · Opening DICOM files won't open: common problems and fixes Troubleshoot DICOM files that will not open: incomplete ZIPs, missing images, blank views, browser loading errors, and hospital CD viewer problems. Read guide](https://openmyscan.com/en/guides/dicom-files-wont-open) [G–09 · Sharing How to send an MRI to another doctor You have an MRI from hospital A and want hospital B to see it. Three practical paths: the original CD, their patient portal, or a ZIP share package. Read guide](https://openmyscan.com/en/guides/how-to-send-mri-to-another-doctor) OpenMyScan is a viewer for images you already own. It is not a diagnostic tool, is not FDA- or CE-cleared, and does not replace professional medical advice. Always consult your doctor.