Files with the .DCM extension

We are new users of Acronis True Image 2014 Premium. Since using the new backup program we have begun to note file duplicates on our hard drive. Some of our existing files have a .DCM extension attached to the original files name (including original extension). Does the Acronis image backup process generate these files?

Some of our research suggests that these files can be associated with an image backup program. Is this a shadow copy used by Acronis? If so, why are they left on our hard disk once the backup operation is complete?

Thank you for any assistance.