12.5. DICOM Data and Coordinates

A mixed type are DICOM "coordinates". They are mostly world coordinates but refer to the patient axes.

Figure 12.4. World Coordinates in Context of the Human Body

World Coordinates in Context of the Human Body

The DICOM (Digital Imaging and Communications in Medicine) standard is a data format that groups information into data sets. This way, the image data is always kept together with all meta information like patient ID, study time, series time, acquisition data etc. The image slice itself is essentially just another tag with pixel information.

DICOM tags have unique numbers, encoded as 2x4 numbers in hexadecimal notation (0000,0000). The first four numbers are the data group, the second four numbers the data set/tag.


Although DICOM is a standard, often the data that is received / recorded does not follow the standard. Wrongly used tags or missing mandatory tags may cause problems in data processing.

Some typical modules for DICOM handling:


For handling and manipulating DICOM data, the DICOM toolkit “DCMTK” (DICOM@offis) is recommended. Parts of this toolkit are also used in MeVisLab.

Figure 12.5. The DICOM Tag Browser

The DICOM Tag Browser