ACR is an extension of files that are used in medicine to store raster images saved in a format developed by the American College of Radiology (ACR) and the National Electrical Manufacturers Association (NEMA). ACR files were digital medical records that were the results of tests such as computed tomography, magnetic resonance imaging or ultrasound. These files were widely used to exchange information.

Currently, the ACR format is rarely used and is considered obsolete.