What is DICOM in medical imaging?

DICOM (Digital Imaging and Communications in Medicine) is the universal standard for medical imaging, defining both the file format (pixel data with rich metadata) and network protocols for image storage, retrieval, and display. It operates on a hierarchy: Patient → Study → Series → Instance. DICOMweb (WADO-RS, STOW-RS, QIDO-RS) is the modern RESTful extension enabling cloud-native imaging and AI integration.