DICOM Core Information Structure and Explanation: Understanding Medical Imaging Standards
DICOM Basic Concepts DICOM (Digital Imaging and Communications in Medicine) is the international standard (ISO 12052) for medical imaging and related information, used for storing, exchanging, and transmitting medical images and related data. DICOM files not only contain pixel data (the image itself) but also contain extensive metadata describing the image, organized as “data elements” within “Information Object Definitions” (IOD). ✅ 1. Core Structure of DICOM Files File Header (File Meta Information) 128-byte fixed-length preamble (usually all 0x00, optional) 4-byte DICOM prefix “DICM” File meta information group (Group 0002), including: (0002,0000) File Meta Information Group Length (0002,0001) File Meta Information Version (0002,0002) Media Storage SOP Class UID (0002,0003) Media Storage SOP Instance UID (0002,0010) Transfer Syntax UID (0002,0012) Implementation Class UID (0002,0013) Implementation Version Name Dataset Contains actual image information and metadata, following specific IODs (such as CT Image IOD, MR Image IOD, etc.) Data elements organized by tags, formatted as (gggg,eeee), where gggg is the group number and eeee is the element number Each data element includes: Tag, VR (Value Representation), Value Length, Value ✅ 2. Core Information Object (IOD) Structure Explanation Each DICOM image belongs to a SOP Class (Service-Object Pair Class), for example: ...