RFC3240

Network Working Group D. Clunie Request for Comments: 3240 E. Cordonnier Category: Informational DICOM Committee

                                                       February 2002

    Digital Imaging and Communications in Medicine (DICOM) -
          Application/dicom MIME Sub-type Registration

Status of this Memo

This memo provides information for the Internet community. It does not specify an Internet standard of any kind. Distribution of this memo is unlimited.

Copyright Notice

Copyright (C) The Internet Society (2002). All Rights Reserved.

Abstract

This document describes the registration of the MIME sub-type application/dicom (Digital Imaging and Communications in Medicine). The baseline encoding is defined by the DICOM Standards Committee in "Digital Imaging and Communications in Medicine".

DICOM Definition

Digital Imaging and Communications in Medicine (DICOM) specifies protocols and formats for the exchange of images, time-based waveforms, reports, and associated information for medical applications.

Individual DICOM objects (such as images) may be encapulsated in files and exchanged by e-mail using the Media Type defined herein. In addition, a set of DICOM files may be described by an index file, DICOMDIR, which may accompany the files that it references.

IANA Registration

MIME media type name: Application

MIME subtype name: dicom

Required parameters:

  "id" is constructed from a DICOM File ID (see DICOM PS3.11).  The
  total length is limited to 71 characters.  Each component is
  limited to 8 characters.  The delimiter is a forward slash "/".
  There is never a leading delimiter (i.e., this is not a
  traditional path from a root directory).

  If a DICOMDIR (which provides an index of files) is included, then
  it will refer to other DICOM files in the file set by use of this
  File ID.  The File ID is not encoded within each DICOM file.  If a
  DICOMDIR is not present, then the "id" parameter may be absent.
  Note that the DICOMDIR will also have a Media Type of
  application/dicom and is distinguished from other files by its ID
  of "DICOMDIR".

  For example:
   "ROOTDIR/SUBDIR1/MRSCAN/A789FD07/19991024/ST00234/S00003/I00023"

  Each component shall be character strings made of characters from
  a subset of the G0 repertoire of ISO 8859.  This subset consists
  of uppercase alphabetic characters, numeric characters and
  underscore.  The following characters are permissable:

  A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V,
  W, X, Y, Z (uppercase)
  1, 2, 3, 4, 5, 6, 7, 8, 9, 0 and _ (underscore)

Optional parameters:

  none

Encoding considerations:

  The DICOM information is binary, therefore the encoding used shall
  support lossless transfer of binary information.  Typically, the
  Content-Transfer-Encoding would be set to "Base64".

  Multiple DICOM parts should be included as a Multipart/related
  entity [2387].  Receiving agents shall also support multiple parts
  as a Multipart/mixed entity.  When multiple DICOM parts are
  included, one of the parts may be a DICOMDIR, in which case, all
  the files referred to by the DICOMDIR shall also be present.  The
  DICOMDIR is not required to be the first Application/dicom part
  encoded in the message, in which case the optional "start"
  parameter should refer to the content-id of the part containing
  the DICOMDIR.

  Multiple DICOM Application/dicom parts may be included with other
  types of parts as a Multipart/mixed entity.

Security considerations:

  Application/dicom parts contain medical information, including
  individual demographic information.  Accordingly, their exchange
  should be restricted to a secure network or within a secure
  wrapper that protects a patient's right to confidentiality
  according to local and national policy.  The specific security
  mechanisms are outside the scope of this proposal.  Such
  mechanisms as Secured MIME (S/MIME) [2633] or similar might be
  appropriate.

Interoperability considerations:

  Because DICOM information is specific to the medical (imaging)
  domain, generic e-mail applications may not be able to interpret
  the information.

  The Media Type has been designed in order to allow for

  (i)   DICOM aware applications to interoperate,
  (ii)  generic applications to save the files in a form
        recognizable as DICOM files, that a DICOM application may
        subsequently use.

Published specification:

  The Digital Imaging and Communications in Medicine (DICOM)
  Standard is a standard of the DICOM Standards Committee, published
  by the National Electrical Manufacturers Association (NEMA), 1300
  N. 17th Street, Rosslyn, Virginia 22209 USA,
  (http://medical.nema.org).

Applications which use this media:

  Biomedical imaging applications.

Additional information:

  1. Magic number(s): "DICM" after 128 byte preamble indicates DICOM
                        PS 3.10 file

  2. File extension(s): ".dcm" is recommended for files saved to
                          disk (other than DICOMDIR)

  3. Macintosh file type code:  Macintosh File Type "DICM" is
                                 recommended

  4. Object Identifiers: none

Person to contact for further information:

  1. Name: Howard Clark
  2. E-mail: [email protected]

Intended usage:

  Common

  Interchange of biomedical images.

Author/Change controller:

  DICOM Standards Committee

References

[DICOM] DICOM Standards Committee, "Digital Imaging and

        Communications in Medicine", 2001.

[2387] Levinson, E., "The MIME Multipart/Related Content-type", RFC

        2387, August 1998.

[2633] Ramsdell, B., "S/MIME Version 3 Message Specification", RFC

        2633, June 1999.

Authors' Addresses

David Clunie RadPharm 943 Heiden Road Bangor PA 18013 USA

Phone: +1-570-897-7123 Fax: +1-425-930-0171 EMail: [email protected]

Emmanuel Cordonnier Etiam 20 rue du Pr J. Pecker 35000 Rennes France

Phone: +33(0)299 14 33 88 Fax: +33(0)299 14 33 80 EMail: [email protected]

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