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.
PNG is a raster graphic data storage format that uses lossless compression algorithm to Deflate. PNG was created as a free format to replace GIF. PNG supports three main types of raster images: grayscale image, a color indexed image and the color image. PNG format stores graphical information in a compressed form.