This is an international format that was developed for the purpose of storing images of the body taken with medical imaging equipment. It includes magnetic resonance and computer tomography images, ultrasound images and fluoroscopy, as well as images taken with other medical imaging equipment. DCM also stores patient information in the metadata, which form part of a single file.
PGM is a storage format for grayscale images. Files in this format can be opened using software: ACDSee Photo Manager 14, ACD Systems Canvas 15, Corel PaintShop Pro X4. This type of file can be edited with a text editor. PGM files can be in two versions: P2 / P5. P2 are readable, P5 - to binary formats.