The DICOM media exchange format specifies a general model for the storage and interchange of medical imaging information on a broad range of physical storage media. Parts 10, 11, and 12 of the DICOM standard deal with the DICOM media exchange format.

Part 10 specifies the file format, including the directory structure. Note that DICOM has a very unique directory structure, which allows one to read the DICOMDIR file on a DICOM exchange CD, for example, and display the key information of all the images, which could be thousands, before deciding which ones to retrieve. Because this directory is DICOM-specific, one needs a DICOM application to interpret the information.

The file system itself is PC-standard, which means that when opening it with Microsoft Explorer, one can see the files listed. DICOM CD can also be defined as, Media formats or Physical Media for Data Interchange which defines a number of selected Physical Medium and corresponding Media Formats. These Media Formats and Physical Medium selections are referenced by one or more of the Application Profiles of PS 3.11. PS 3.12 which is intended to be extended as the technologies related to Physical Medium evolve.

DICOM CDs are known to have compatibility problems, has led to the creation of the Portable Data for Imaging profile by IHE.  This profile identifies the most commonly made mistakes when generating these CDs.