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.
PBM is a Portable image in black and white. Can be opened with programs: Adobe Photoshop CS, ACD Systems Canvas 15, ACD Systems ACDSee 17, Newera Graphics Converter Pro, Corel PaintShop Pro X6. File contains 1 bit per pixel. PBM is a kind of file format PPM. And can be readable or binary.