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What is a DICOM File?


Question: What is a DICOM File?

Did you find a DICOM file on your computer and wonder what program should open it? Maybe someone emailed you a DICOM file but you're not sure how to use it. Perhaps you tried to open the DICOM file but Windows told you that it could not open it.

Before you can open a DICOM file (assuming it's even a file format that's intended to be viewed or edited), you'll need to determine what kind of file the .DICOM file extension refers to.

Answer: A file with the DICOM file extension is a DICOM Digital Imaging and Communations in Medicine Format Bitmap file.

Other types of files may also use the DICOM file extension. If you know of any additional file formats that use the .DICOM extension, please let me know so I can update this information.

How To Open a DICOM File

The easiest way to open a DICOM file is to double-click on it and let your PC decide which default application should open the file. If no program opens the DICOM file then you probably don't have an application installed that can view and/or edit DICOM files.

Warning: Take great care when opening executable file formats received via email or downloaded from websites you're not familiar with. See my List of Executable File Extensions for a listing of file extensions to avoid and why.

The easiest way to view a DICOM file is probably with the free, web-based Jack Imaging viewer - just drag your DICOM file into the square on the screen to view it. If you've received a file from your doctor that's supposed to have medical images on it, like from an X-ray, this tool will let you view it.

If you'd rather not use a web-based tool to open your DICOM files, the free the free MicroDicom Viewer program is another good option. Once the X-ray or other medical image is opened with MicroDicom Viewer, you can view meta data, export it as a JPG, TIF, or other common image file type, and more.

DICOM files can also be opened with Adobe Photoshop and GIMP.

If you're having trouble opening the file, it's possible that it's compressed so try renaming the file so it ends in .zip and then uncompressing it with a free file extractor program, like PeaZip or 7-Zip.

If you know anything else useful about DICOM files, please let me know so I can update this page.

Tip: Use Notepad or another text editor to open the DICOM file. Many files are text-only files meaning no matter the file extension, a text editor may be able to properly display the file's contents. This may or may not be the case with DICOM files but it's worth a try.

If you find that an application on your PC does try to open the DICOM file but it's the wrong application or if you would rather have another installed program open DICOM files, see my How To Change the Default Program for a Specific File Extension guide for making that change in Windows.

How To Convert a DICOM File

There are two main ways to attempt to convert a DICOM file to another file type:

The first option involving opening the DICOM file in its native program is preferable because it's both easier and will probably result in a more accurate file conversion. Of course if you don't have a program that opens DICOM files, a third-party file conversion tool (the second option) could be very useful.

Important: You cannot usually change a file extension (like the DICOM file extension) to one that your computer recognizes and expect the newly renamed file to be usable. An actual file format conversion using one of the methods described above must take place in most cases.

Still Having Problems Opening or Using a DICOM File?

See Get More Help for information about contacting me on social networks or via email, posting on tech support forums, and more. Let me know what kinds of problems you're having with opening or using the DICOM file and I'll see what I can do to help.

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