What is Digital Imaging and Communication in Medicine (DICOM) and how does it work?

When it comes to transferring digital images for telemedicine diagnostic purposes, it is important to adhere to the correct protocols. As the explosion of digital imaging technology has continued, so too has the improvement of standards and protocols.

A standard for communications among medical imaging devices has been set by the National Electronic Manufacturers Association (NEMA) in conjunction with the American College of Radiology since 1985.

The DICOM, which stands for Digital Imaging and Communications in Medicine, is the current standard for handling, storing, printing, and transmitting information in medical imaging. It includes a file format definition and a network communications protocol. It has been consistently upgraded under the acronym DICOM since 1993.

DICOM files can be exchanged between two entities that are capable of receiving image and patient data in DICOM format. In this respect, it is the standard for todays medical imagining practices.

Within the DICOM standards are 4 key areas to understand and abide by:

1) DICOM Transfer Syntaxes

A Transfer Syntax is a set of encoding rules able to unambiguously represent one or more Abstract Syntaxes. In particular, it allows communicating Application Entities to negotiate common encoding techniques they both support (e.g., byte ordering, compression, etc.). A Transfer Syntax is an attribute of a Presentation Context, one or more of which are negotiated at the establishment of an Association between DICOM Application Entities.

The full list of syntaxes is available here.


A Service-Object Pair (SOP) Class is defined by the union of an Information Object Definition (IOD) and a DICOM Service Elements (DIMSE). The SOP Class definition contains the rules and semantics which may restrict the use of the services in the DIMSE Service Group or the Attributes of the IOD.

The full list of SOPs is available here.

3) DICOM Modality

A DICOM data object consists of a number of attributes, including items such as name, ID, etc., and also one special attribute containing the image pixel data.  One of attributes – DICOM modality, that represents DICOM file type. In addition, each attribute also has a Value Multiplicity to indicate the number of data elements contained in the attribute.

The full list of Modalities is available here.

4) DICOM Space Storage

Every DICOM file type made by different machines that generate data in different sizes. We present most common features that we are facing now.

The full list of space storage details is available here.

For doctors wanting to transfer and share digital images as a part of their diagnostic process, it is important to be aware of following and adhering to the DICOM standards. However the current generations of telemedicine software do comply with these standards, making the role of the doctor an easier one.