DICOM stands for Digital Imaging and Communications in Medicine. It was first published in 1993 by the National Electrical Manufacturers Association (NEMA) and was developed together with the American College of Radiology (ACR). The original DICOM standard was called the ACR-NEMA standard, after the two organizations.

DICOM was initiated by the ACR to address the need for connectivity between imaging equipment. The current version of DICOM is called DICOM version 3.0. Typically, updated versions of the DICOM standard are published every other year.

DICOM consists of a protocol (or in layman’s terms, an agreement on how to communicate) which provides certain functionality and offers an integrated environment which will facilitate an efficient workflow. In addition, it defines exactly the data formats of the information to be exchanged.

From a high level, the DICOM protocol consists of a two-step process. The first step is to communicate what information will be exchanged. This negotiation is critical to ensure that the receiver can indeed understand and interpret the information. DICOM is, therefore, fundamentally different from a broadcast, which is only a one-way transmission. After the negotiation has been completed successfully, step two takes place, during which the actual information exchange occurs. Each interaction is executed by specific commands, which are always being acknowledged.

A copy of the DICOM Standard can be downloaded from http://medical.nema.org/.