Digital Imaging and Communications in Medicine
Encyclopedia
DICOM is a standard for handling, storing, printing, and transmitting
information in medical imaging
. It includes a file format
definition and a network communications protocol
. The communication protocol is an application protocol that uses TCP/IP to communicate between systems. DICOM files can be exchanged between two entities that are capable of receiving image and patient data in DICOM format. The National Electrical Manufacturers Association
(NEMA) holds the copyright to this standard. It was developed by the DICOM Standards Committee, whose members are also partly members of NEMA.
DICOM enables the integration of scanners, servers, workstations, printers, and network hardware from multiple manufacturers into a picture archiving and communication system
(PACS). The different devices come with DICOM conformance statements which clearly state the DICOM classes they support. DICOM has been widely adopted by hospital
s and is making inroads in smaller applications like dentists' and doctors' offices.
DICOM is known as NEMA
standard PS3, and as ISO standard 12052:2006 "Health informatics -- Digital imaging and communication in medicine (DICOM) including workflow and data management".
The links below are to the 2009 version published in January 2010. Additions to the standard (Supplements and Change Proposals) since that publication are available through the DICOM Web site.
(ACR) and National Electrical Manufacturers Association
(NEMA).
In the beginning of the 1980s it was almost impossible for anyone other than manufacturers of computed tomography
or magnetic resonance imaging
devices to decode the images that the machines generated. Radiologists and medical physicists wanted to use the images for dose-planning for radiation therapy
. ACR and NEMA joined forces and formed a standard committee in 1983. Their first standard, ACR/NEMA 300, was released in 1985. Very soon after its release, it became clear that improvements were needed. The text was vague and had internal contradictions.
In 1988 the second version was released. This version gained more acceptance among vendors. The image transmission was specified as over a dedicated 25 differential (EIA-485) pair cable. The first demonstration of ACR/NEMA V2.0 interconnectivity technology was held at Georgetown University, May 21–23, 1990. Six companies participated in this event, DeJarnette Research Systems, General Electric Medical Systems, Merge Technologies, Siemens Medical Systems, Vortech (acquired by Kodak that same year) and 3M. Commercial equipment supporting ACR/NEMA 2.0 was presented at the annual meeting of the Radiological Society of North America (RSNA) in 1990 by these same vendors. Many soon realized that the second version also needed improvement. Several extensions to ACR/NEMA 2.0 were created, like Papyrus (developed by the University Hospital of Geneva, Switzerland) and SPI, (Standard Product Interconnect, driven by Siemens Medical Systems and Philips Medical Systems).
The first large scale deployment of ACR/NEMA technology was made in 1992 by the US Army and Air Force as part of the MDIS (Medical Diagnostic Imaging Support) program run out of Ft. Detrick, Maryland. Loral Aerospace and Siemens Medical Systems led a consortium of companies in deploying the first US military PACS (Picture Archiving and Communications System)
at all major Army and Air Force medical treatment facilities and teleradiology nodes at a large number of US military clinics. DeJarnette Research Systems and Merge Technologies provided the modality gateway interfaces from third party imaging modalities to the Siemens SPI network. The Veterans Administration and the Navy also purchased systems off this contract.
In 1993 the third version of the standard was released. Its name was then changed to DICOM so as to improve the possibility of international acceptance as a standard. New service classes were defined, network support added and the Conformance Statement was introduced. Officially, the latest version of the standard is still 3.0, however, it has been constantly updated and extended since 1993. Instead of using the version number the standard is often version-numbered using the release year, like "the 2007 version of DICOM".
While the DICOM standard has achieved a near universal level of acceptance amongst medical imaging equipment vendors and healthcare IT organizations, the standard has its limitations. DICOM is a standard directed at addressing technical interoperability issues in medical imaging. It is not a framework or architecture for achieving a useful clinical workflow. RSNA's Integrating the Healthcare Enterprise (IHE)
initiative layered on top of DICOM (and HL-7) provides this final piece of the medical imaging interoperability puzzle.
s. That means that a file of a chest X-Ray image, for example, actually contains the patient ID within the file, so that the image can never be separated from this information by mistake. This is similar to the way that image formats such as JPEG
can also have embedded tags to identify and otherwise describe the image.
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 (i.e. logically, the main object has no "header" as such: merely a list of attributes, including the pixel data). A single DICOM object can only contain one attribute containing pixel data. For many modalities, this corresponds to a single image. But note that the attribute may contain multiple "frames", allowing storage of cine loops or other multi-frame data. Another example is NM data, where an NM image by definition is a multi-dimensional multi-frame image. In these cases three- or four-dimensional data can be encapsulated in a single DICOM object. Pixel data can be compressed using a variety of standards, including JPEG
, JPEG Lossless, JPEG 2000
, and Run-length encoding (RLE)
. LZW
(zip) compression can be used for the whole data set (not just the pixel data) but this is rarely implemented.
DICOM uses three different Data Element encoding schemes. With Explicit Value Representation (VR) Data Elements, for VRs that are not OB, OW, OF, SQ, UT, or UN, the format for each Data Element is: GROUP (2 bytes) ELEMENT (2 bytes) VR (2 bytes) LengthInByte (2 bytes) Data (variable length). For the other Explicit Data Elements or Implicit Data Elements, see section 7.1 of Part 5 of the DICOM Standard.
The same basic format is used for all applications, including network and file usage, but when written to a file, usually a true "header" (containing copies of a few key attributes and details of the application which wrote it) is added.
In addition to a Value Representation, each attribute also has a Value Multiplicity to indicate the number of data elements contained in the attribute. For character string value representations, if more than one data element is being encoded, the successive data elements are separated by the backslash character "\".
or workstation.
.
It helps give the radiology department a more precise handle on resource (acquisition station) use. Also known as MPPS, this service allows a modality to better coordinate with image storage servers by giving the server a list of objects to send before or while actually sending such objects.
DICOM restricts the filenames on DICOM media to 8 characters (some systems wrongly use 8.3, but this does not conform to the standard). No information must be extracted from these names (PS3.10 Section 6.2.3.2). This is a common source of problems with media created by developers who did not read the specifications carefully. This is a historical requirement to maintain compatibility with older existing systems. It also mandates the presence of a media directory, the DICOMDIR file, which provides index and summary information for all the DICOM files on the media.
The DICOMDIR information provides substantially greater information about each file than any filename could, so there is less need for meaningful file names.
DICOM files typically have a .dcm file extension if they are not part of a DICOM media (which requires them to be without extension).
The MIME
type for DICOM files is defined by RFC 3240 as application/dicom.
The Uniform Type Identifier
type for DICOM files is org.nema.dicom.
There is also an ongoing media exchange test and "connectathon" process for CD media and network operation that is organized by the IHE organization.
numbers by the Internet Assigned Numbers Authority
(IANA):
The standard recommends but does not require the use of these port numbers.
Data transmission
Data transmission, digital transmission, or digital communications is the physical transfer of data over a point-to-point or point-to-multipoint communication channel. Examples of such channels are copper wires, optical fibres, wireless communication channels, and storage media...
information in medical imaging
Medical imaging
Medical imaging is the technique and process used to create images of the human body for clinical purposes or medical science...
. It includes a file format
File format
A file format is a particular way that information is encoded for storage in a computer file.Since a disk drive, or indeed any computer storage, can store only bits, the computer must have some way of converting information to 0s and 1s and vice-versa. There are different kinds of formats for...
definition and a network communications protocol
Communications protocol
A communications protocol is a system of digital message formats and rules for exchanging those messages in or between computing systems and in telecommunications...
. The communication protocol is an application protocol that uses TCP/IP to communicate between systems. DICOM files can be exchanged between two entities that are capable of receiving image and patient data in DICOM format. The National Electrical Manufacturers Association
National Electrical Manufacturers Association
is the association of electrical and medical imaging equipment manufacturers. Founded in 1926 and headquartered near Washington, D.C., its approximately manufacture products used in the generation, transmission, distribution, control, and end use of electricity. These products are used in utility,...
(NEMA) holds the copyright to this standard. It was developed by the DICOM Standards Committee, whose members are also partly members of NEMA.
DICOM enables the integration of scanners, servers, workstations, printers, and network hardware from multiple manufacturers into a picture archiving and communication system
Picture archiving and communication system
A picture archiving and communication system is a medical imaging technology which provides economical storage of, and convenient access to, images from multiple modalities . Electronic images and reports are transmitted digitally via PACS; this eliminates the need to manually file, retrieve, or...
(PACS). The different devices come with DICOM conformance statements which clearly state the DICOM classes they support. DICOM has been widely adopted by hospital
Hospital
A hospital is a health care institution providing patient treatment by specialized staff and equipment. Hospitals often, but not always, provide for inpatient care or longer-term patient stays....
s and is making inroads in smaller applications like dentists' and doctors' offices.
DICOM is known as NEMA
National Electrical Manufacturers Association
is the association of electrical and medical imaging equipment manufacturers. Founded in 1926 and headquartered near Washington, D.C., its approximately manufacture products used in the generation, transmission, distribution, control, and end use of electricity. These products are used in utility,...
standard PS3, and as ISO standard 12052:2006 "Health informatics -- Digital imaging and communication in medicine (DICOM) including workflow and data management".
Parts of the DICOM standard
The DICOM standard is divided into related but independent parts:The links below are to the 2009 version published in January 2010. Additions to the standard (Supplements and Change Proposals) since that publication are available through the DICOM Web site.
- PS 3.1:
- PS 3.2:
- PS 3.3:
- PS 3.4:
- PS 3.5:
- PS 3.6:
- PS 3.7:
- PS 3.8:
- PS 3.9: Retired (formerly Point-to-Point Communication Support for Message Exchange)
- PS 3.10:
- PS 3.11:
- PS 3.12:
- PS 3.13: Retired (formerly Print Management Point-to-Point Communication Support)
- PS 3.14:
- PS 3.15:
- PS 3.16:
- PS 3.17:
- PS 3.18:
History
DICOM is the third version of a standard developed by American College of RadiologyAmerican College of Radiology
The American College of Radiology , founded in 1923, is a non-profit professional medical association composed of diagnostic radiologists, radiation oncologists, interventional radiologists, nuclear medicine physicians, and medical physicists. It is based in Reston, Virginia, with offices in...
(ACR) and National Electrical Manufacturers Association
National Electrical Manufacturers Association
is the association of electrical and medical imaging equipment manufacturers. Founded in 1926 and headquartered near Washington, D.C., its approximately manufacture products used in the generation, transmission, distribution, control, and end use of electricity. These products are used in utility,...
(NEMA).
In the beginning of the 1980s it was almost impossible for anyone other than manufacturers of computed tomography
Computed tomography
X-ray computed tomography or Computer tomography , is a medical imaging method employing tomography created by computer processing...
or magnetic resonance imaging
Magnetic resonance imaging
Magnetic resonance imaging , nuclear magnetic resonance imaging , or magnetic resonance tomography is a medical imaging technique used in radiology to visualize detailed internal structures...
devices to decode the images that the machines generated. Radiologists and medical physicists wanted to use the images for dose-planning for radiation therapy
Radiation therapy
Radiation therapy , radiation oncology, or radiotherapy , sometimes abbreviated to XRT or DXT, is the medical use of ionizing radiation, generally as part of cancer treatment to control malignant cells.Radiation therapy is commonly applied to the cancerous tumor because of its ability to control...
. ACR and NEMA joined forces and formed a standard committee in 1983. Their first standard, ACR/NEMA 300, was released in 1985. Very soon after its release, it became clear that improvements were needed. The text was vague and had internal contradictions.
In 1988 the second version was released. This version gained more acceptance among vendors. The image transmission was specified as over a dedicated 25 differential (EIA-485) pair cable. The first demonstration of ACR/NEMA V2.0 interconnectivity technology was held at Georgetown University, May 21–23, 1990. Six companies participated in this event, DeJarnette Research Systems, General Electric Medical Systems, Merge Technologies, Siemens Medical Systems, Vortech (acquired by Kodak that same year) and 3M. Commercial equipment supporting ACR/NEMA 2.0 was presented at the annual meeting of the Radiological Society of North America (RSNA) in 1990 by these same vendors. Many soon realized that the second version also needed improvement. Several extensions to ACR/NEMA 2.0 were created, like Papyrus (developed by the University Hospital of Geneva, Switzerland) and SPI, (Standard Product Interconnect, driven by Siemens Medical Systems and Philips Medical Systems).
The first large scale deployment of ACR/NEMA technology was made in 1992 by the US Army and Air Force as part of the MDIS (Medical Diagnostic Imaging Support) program run out of Ft. Detrick, Maryland. Loral Aerospace and Siemens Medical Systems led a consortium of companies in deploying the first US military PACS (Picture Archiving and Communications System)
Picture archiving and communication system
A picture archiving and communication system is a medical imaging technology which provides economical storage of, and convenient access to, images from multiple modalities . Electronic images and reports are transmitted digitally via PACS; this eliminates the need to manually file, retrieve, or...
at all major Army and Air Force medical treatment facilities and teleradiology nodes at a large number of US military clinics. DeJarnette Research Systems and Merge Technologies provided the modality gateway interfaces from third party imaging modalities to the Siemens SPI network. The Veterans Administration and the Navy also purchased systems off this contract.
In 1993 the third version of the standard was released. Its name was then changed to DICOM so as to improve the possibility of international acceptance as a standard. New service classes were defined, network support added and the Conformance Statement was introduced. Officially, the latest version of the standard is still 3.0, however, it has been constantly updated and extended since 1993. Instead of using the version number the standard is often version-numbered using the release year, like "the 2007 version of DICOM".
While the DICOM standard has achieved a near universal level of acceptance amongst medical imaging equipment vendors and healthcare IT organizations, the standard has its limitations. DICOM is a standard directed at addressing technical interoperability issues in medical imaging. It is not a framework or architecture for achieving a useful clinical workflow. RSNA's Integrating the Healthcare Enterprise (IHE)
Integrating the Healthcare Enterprise
IHE is an initiative by healthcare professionals and industry to improve the way computer systems in healthcare share information.In 1997, a consortium of radiologists and information technology experts formed IHE, or "Integrating the Healthcare Enterprise." IHE created and operates a process...
initiative layered on top of DICOM (and HL-7) provides this final piece of the medical imaging interoperability puzzle.
Derivations
There are some derivations from the DICOM standard into other application areas. This includes- DICONDE - Digital Imaging and Communication in Nondestructive Evaluation, was established in 2004 as a way for nondestructive testingNondestructive testingNondestructive testing or Non-destructive testing is a wide group of analysis techniques used in science and industry to evaluate the properties of a material, component or system without causing damage....
manufacturers and users to share image data. - DICOS - Digital Imaging and Communication in Security was established in 2009 to be used for image sharing in airport securityAirport securityAirport security refers to the techniques and methods used in protecting airports and aircraft from crime.Large numbers of people pass through airports. This presents potential targets for terrorism and other forms of crime due to the number of people located in a particular location...
.
DICOM Data Format
DICOM differs from some, but not all, data formats in that it groups information into data setData set
A data set is a collection of data, usually presented in tabular form. Each column represents a particular variable. Each row corresponds to a given member of the data set in question. Its values for each of the variables, such as height and weight of an object or values of random numbers. Each...
s. That means that a file of a chest X-Ray image, for example, actually contains the patient ID within the file, so that the image can never be separated from this information by mistake. This is similar to the way that image formats such as JPEG
JPEG
In computing, JPEG . The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and image quality. JPEG typically achieves 10:1 compression with little perceptible loss in image quality....
can also have embedded tags to identify and otherwise describe the image.
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 (i.e. logically, the main object has no "header" as such: merely a list of attributes, including the pixel data). A single DICOM object can only contain one attribute containing pixel data. For many modalities, this corresponds to a single image. But note that the attribute may contain multiple "frames", allowing storage of cine loops or other multi-frame data. Another example is NM data, where an NM image by definition is a multi-dimensional multi-frame image. In these cases three- or four-dimensional data can be encapsulated in a single DICOM object. Pixel data can be compressed using a variety of standards, including JPEG
JPEG
In computing, JPEG . The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and image quality. JPEG typically achieves 10:1 compression with little perceptible loss in image quality....
, JPEG Lossless, JPEG 2000
JPEG 2000
JPEG 2000 is an image compression standard and coding system. It was created by the Joint Photographic Experts Group committee in 2000 with the intention of superseding their original discrete cosine transform-based JPEG standard with a newly designed, wavelet-based method...
, and Run-length encoding (RLE)
Run-length encoding
Run-length encoding is a very simple form of data compression in which runs of data are stored as a single data value and count, rather than as the original run...
. LZW
LZW
Lempel–Ziv–Welch is a universal lossless data compression algorithm created by Abraham Lempel, Jacob Ziv, and Terry Welch. It was published by Welch in 1984 as an improved implementation of the LZ78 algorithm published by Lempel and Ziv in 1978...
(zip) compression can be used for the whole data set (not just the pixel data) but this is rarely implemented.
DICOM uses three different Data Element encoding schemes. With Explicit Value Representation (VR) Data Elements, for VRs that are not OB, OW, OF, SQ, UT, or UN, the format for each Data Element is: GROUP (2 bytes) ELEMENT (2 bytes) VR (2 bytes) LengthInByte (2 bytes) Data (variable length). For the other Explicit Data Elements or Implicit Data Elements, see section 7.1 of Part 5 of the DICOM Standard.
The same basic format is used for all applications, including network and file usage, but when written to a file, usually a true "header" (containing copies of a few key attributes and details of the application which wrote it) is added.
DICOM Value Representations
Extracted from Chapter 6.2 of- PS 3.5:
| Value Representation | Description |
|---|---|
| AE | Application Entity |
| AS | Age String |
| AT | Attribute Tag |
| CS | Code String |
| DA | Date |
| DS | Decimal String |
| DT | Date/Time |
| FL | Floating Point Single (4 bytes) |
| FD | Floating Point Double (8 bytes) |
| IS | Integer String |
| LO | Long String |
| LT | Long Text |
| OB | Other Byte |
| OF | Other Float |
| OW | Other Word |
| PN | Person Name |
| SH | Short String |
| SL | Signed Long |
| SQ | Sequence of Items |
| SS | Signed Short |
| ST | Short Text |
| TM | Time |
| UI | Unique Identifier |
| UL | Unsigned Long |
| UN | Unknown |
| US | Unsigned Short |
| UT | Unlimited Text |
In addition to a Value Representation, each attribute also has a Value Multiplicity to indicate the number of data elements contained in the attribute. For character string value representations, if more than one data element is being encoded, the successive data elements are separated by the backslash character "\".
DICOM Services
DICOM consists of many different services, most of which involve transmission of data over a network, and the file format below is a later and relatively minor addition to the standard.Store
The DICOM Store service is used to send images or other persistent objects (structured reports, etc.) to a PACSPicture archiving and communication system
A picture archiving and communication system is a medical imaging technology which provides economical storage of, and convenient access to, images from multiple modalities . Electronic images and reports are transmitted digitally via PACS; this eliminates the need to manually file, retrieve, or...
or workstation.
Storage Commitment
The DICOM storage commitment service is used to confirm that an image has been permanently stored by a device (either on redundant disks or on backup media, e.g. burnt to a CD). The Service Class User (SCU: similar to a client), a modality or workstation, etc., uses the confirmation from the Service Class Provider (SCP: similar to a server), an archive station for instance, to make sure that it is safe to delete the images locally.Query/Retrieve
This enables a workstation to find lists of images or other such objects and then retrieve them from a PACSPicture archiving and communication system
A picture archiving and communication system is a medical imaging technology which provides economical storage of, and convenient access to, images from multiple modalities . Electronic images and reports are transmitted digitally via PACS; this eliminates the need to manually file, retrieve, or...
.
Modality Worklist
This enables a piece of imaging equipment (a modality) to obtain details of patients and scheduled examinations electronically, avoiding the need to type such information multiple times (and the mistakes caused by retyping).Modality Performed Procedure Step
A complementary service to Modality Worklist, this enables the modality to send a report about a performed examination including data about the images acquired, beginning time, end time, and duration of a study, dose delivered, etc.It helps give the radiology department a more precise handle on resource (acquisition station) use. Also known as MPPS, this service allows a modality to better coordinate with image storage servers by giving the server a list of objects to send before or while actually sending such objects.
Printing
The DICOM Printing service is used to send images to a DICOM Printer, normally to print an "X-Ray" film. There is a standard calibration (defined in DICOM Part 14) to help ensure consistency between various display devices, including hard copy printout.Off-line Media (DICOM Files)
The off-line media files correspond to Part 10 of the DICOM standard. It describes how to store medical imaging information on removable media. Except for the data set containing, for example, an image and demography, it's also mandatory to include the File Meta Information.DICOM restricts the filenames on DICOM media to 8 characters (some systems wrongly use 8.3, but this does not conform to the standard). No information must be extracted from these names (PS3.10 Section 6.2.3.2). This is a common source of problems with media created by developers who did not read the specifications carefully. This is a historical requirement to maintain compatibility with older existing systems. It also mandates the presence of a media directory, the DICOMDIR file, which provides index and summary information for all the DICOM files on the media.
The DICOMDIR information provides substantially greater information about each file than any filename could, so there is less need for meaningful file names.
DICOM files typically have a .dcm file extension if they are not part of a DICOM media (which requires them to be without extension).
The MIME
MIME
Multipurpose Internet Mail Extensions is an Internet standard that extends the format of email to support:* Text in character sets other than ASCII* Non-text attachments* Message bodies with multiple parts...
type for DICOM files is defined by RFC 3240 as application/dicom.
The Uniform Type Identifier
Uniform Type Identifier
A Uniform Type Identifier is a text string used on software provided by Apple Inc. to uniquely identify a given class or type of item...
type for DICOM files is org.nema.dicom.
There is also an ongoing media exchange test and "connectathon" process for CD media and network operation that is organized by the IHE organization.
Application areas
| Modality | Description |
|---|---|
| AS | Modality of type Angioscopy Angioscopy Angioscopy is a medical technique for visualizing the interior of blood vessels. In this technique, a flexible fiberoptic catheter inserted directly into an artery. It can be helpful in diagnosing e.g. arterial embolism.... - Retired |
| BI | Modality of type Biomagnetic Imaging |
| CD | Modality of type Color Flow Doppler - Retired 2008 |
| CF | Modality of type Cinefluorography - Retired |
| CP | Modality of type Colposcopy Colposcopy Colposcopy is a medical diagnostic procedure to examine an illuminated, magnified view of the cervix and the tissues of the vagina and vulva. Many premalignant lesions and malignant lesions in these areas have discernible characteristics which can be detected through the examination... - Retired |
| CR | Modality of type Computed Radiography Computed radiography Computed Radiography uses very similar equipment to conventional radiography except that in place of a film to create the image, an imaging plate made of photostimulable phosphor is used. The imaging plate housed in a special cassette and placed under the body part or object to be examined and... |
| CS | Modality of type Cystoscopy Cystoscopy Cystoscopy is endoscopy of the urinary bladder via the urethra. It is carried out with a cystoscope.Diagnostic cystoscopy is usually carried out with local anaesthesia... - Retired |
| CT | Modality of type Computed Tomography Computed tomography X-ray computed tomography or Computer tomography , is a medical imaging method employing tomography created by computer processing... |
| DD | Modality of type Duplex Doppler - Retired 2008 |
| DG | Modality of type Diaphanography |
| DM | Modality of type Digital Microscopy - Retired |
| DS | Modality of type Digital Subtraction Angiography Digital subtraction angiography Digital subtraction angiography is a type of fluoroscopy technique used in interventional radiology to clearly visualize blood vessels in a bony or dense soft tissue environment. Images are produced using contrast medium by subtracting a 'pre-contrast image' or the mask from later images, once... - Retired |
| DX | Modality of type Digital Radiography |
| EC | Modality of type Echocardiography Echocardiography An echocardiogram, often referred to in the medical community as a cardiac ECHO or simply an ECHO, is a sonogram of the heart . Also known as a cardiac ultrasound, it uses standard ultrasound techniques to image two-dimensional slices of the heart... - Retired |
| ECG | Modality of type Electrocardiograms |
| EM | Modality of type Electron Microscope Electron microscope An electron microscope is a type of microscope that uses a beam of electrons to illuminate the specimen and produce a magnified image. Electron microscopes have a greater resolving power than a light-powered optical microscope, because electrons have wavelengths about 100,000 times shorter than... |
| ES | Modality of type Endoscopy Endoscopy Endoscopy means looking inside and typically refers to looking inside the body for medical reasons using an endoscope , an instrument used to examine the interior of a hollow organ or cavity of the body. Unlike most other medical imaging devices, endoscopes are inserted directly into the organ... |
| FA | Modality of type Fluorescein Angiography Fluorescein angiography Intravenous Fluorescein angiography or fluorescent angiography is a technique for examining the circulation of the retina using the dye tracing method... - Retired |
| FS | Modality of type Fundoscopy - Retired |
| GM | Modality of type General Microscopy |
| HC | Modality of type Hard Copy |
| LP | Modality of type Laparoscopy Laparoscopy Laparoscopy is an operation performed in the abdomen or pelvis through small incisions with the aid of a camera... - Retired |
| LS | Modality of type Laser Laser A laser is a device that emits light through a process of optical amplification based on the stimulated emission of photons. The term "laser" originated as an acronym for Light Amplification by Stimulated Emission of Radiation... Surface Scan |
| MA | Modality of type Magnetic Resonance Angiography Magnetic Resonance Angiography Magnetic resonance angiography is a group of techniques based on Magnetic Resonance Imaging to image blood vessels. Magnetic resonance angiography is used to generate images of the arteries in order to evaluate them for stenosis , occlusion or aneurysms... (retired) |
| MG | Modality of type Mammography Mammography Mammography is the process of using low-energy-X-rays to examine the human breast and is used as a diagnostic and a screening tool.... |
| MR | Modality of type Magnetic Resonance Magnetic resonance imaging Magnetic resonance imaging , nuclear magnetic resonance imaging , or magnetic resonance tomography is a medical imaging technique used in radiology to visualize detailed internal structures... |
| MS | Modality of type Magnetic Resonance Spectroscopy - Retired |
| NM | Modality of type Nuclear Medicine Nuclear medicine In nuclear medicine procedures, elemental radionuclides are combined with other elements to form chemical compounds, or else combined with existing pharmaceutical compounds, to form radiopharmaceuticals. These radiopharmaceuticals, once administered to the patient, can localize to specific organs... |
| OT | Modality of type Other |
| PT | Modality of type Positron Emission Tomography Positron emission tomography Positron emission tomography is nuclear medicine imaging technique that produces a three-dimensional image or picture of functional processes in the body. The system detects pairs of gamma rays emitted indirectly by a positron-emitting radionuclide , which is introduced into the body on a... (PET) |
| RD | Modality of type Radiotherapy Dose (a.k.a. RTDOSE) |
| RF | Modality of type Radio Fluoroscopy Fluoroscopy Fluoroscopy is an imaging technique commonly used by physicians to obtain real-time moving images of the internal structures of a patient through the use of a fluoroscope. In its simplest form, a fluoroscope consists of an X-ray source and fluorescent screen between which a patient is placed... |
| RG | Modality of type Radiographic Imaging (conventional film screen) |
| RTIMAG | Modality of type Radiotherapy Image |
| RP | Modality of type Radiotherapy Plan (a.k.a. RTPLAN) |
| RS | Modality of type Radiotherapy Structure Set (a.k.a RTSTRUCT) |
| RT | Modality of type Radiation Therapy Radiation therapy Radiation therapy , radiation oncology, or radiotherapy , sometimes abbreviated to XRT or DXT, is the medical use of ionizing radiation, generally as part of cancer treatment to control malignant cells.Radiation therapy is commonly applied to the cancerous tumor because of its ability to control... |
| SC | Modality of type Secondary Capture |
| SM | Modality of type Slide Microscopy |
| SR | Modality of type Structured Reporting |
| ST | Modality of type Single-Photon Emission Computed Tomography (retired 2008) |
| TG | Modality of type Thermography Thermography Infrared thermography, thermal imaging, and thermal video are examples of infrared imaging science. Thermal imaging cameras detect radiation in the infrared range of the electromagnetic spectrum and produce images of that radiation, called thermograms... |
| US | Modality of type Ultrasound Ultrasound Ultrasound is cyclic sound pressure with a frequency greater than the upper limit of human hearing. Ultrasound is thus not separated from "normal" sound based on differences in physical properties, only the fact that humans cannot hear it. Although this limit varies from person to person, it is... |
| VF | Modality of type Videofluorography - Retired |
| VL | Modality of type Visible Light |
| XA | Modality of type X-Ray Angiography Angiogram Angiography or arteriography is a medical imaging technique used to visualize the inside, or lumen, of blood vessels and organs of the body, with particular interest in the arteries, veins and the heart chambers... |
| XC | Modality of type External Camera (Photography) |
DICOM transmission protocol port numbers over IP
DICOM have reserved the following TCP and UDP portTCP and UDP port
In computer networking, a port is an application-specific or process-specific software construct serving as a communications endpoint in a computer's host operating system. A port is associated with an IP address of the host, as well as the type of protocol used for communication...
numbers by the Internet Assigned Numbers Authority
Internet Assigned Numbers Authority
The Internet Assigned Numbers Authority is the entity that oversees global IP address allocation, autonomous system number allocation, root zone management in the Domain Name System , media types, and other Internet Protocol-related symbols and numbers...
(IANA):
- 104 well-known port for DICOM over TCPTransmission Control ProtocolThe Transmission Control Protocol is one of the core protocols of the Internet Protocol Suite. TCP is one of the two original components of the suite, complementing the Internet Protocol , and therefore the entire suite is commonly referred to as TCP/IP...
or UDPUser Datagram ProtocolThe User Datagram Protocol is one of the core members of the Internet Protocol Suite, the set of network protocols used for the Internet. With UDP, computer applications can send messages, in this case referred to as datagrams, to other hosts on an Internet Protocol network without requiring...
. Since 104 is in the reserved subset, many operating systems require special privileges to use it. - 2761 registered portRegistered portA registered port is a network port assigned by the Internet Assigned Numbers Authority for use with a certain protocol or application.Ports with numbers lower than those of the registered ports are called well known...
for DICOM using Integrated Secure Communication Layer (ISCL) over TCP or UDP - 2762 registered port for DICOM using Transport Layer SecurityTransport Layer SecurityTransport Layer Security and its predecessor, Secure Sockets Layer , are cryptographic protocols that provide communication security over the Internet...
(TLS) over TCP or UDP - 11112 registered port for DICOM using standard, open communication over TCP or UDP
The standard recommends but does not require the use of these port numbers.
See also
- OsiriXOsiriXOsiriX is an image processing application dedicated to DICOM images produced by medical equipment . Osirix is complementary to existing viewers, in particular to nuclear medicine viewers. It can also read many other file formats: TIFF , JPEG, PDF, AVI, MPEG and Quicktime...
- Image processing application dedicated to DICOM images - GDCMGDCMGrassroots DICOM or GDCM , is a cross-platform library written in C++ for DICOM medical files. It is automatically wrapped to Python/C#/Java & PHP . It supports RAW, JPEG , J2K, JPEG-LS, RLE and deflated...
- DICOM library for medical files
External links
- [ftp://medical.nema.org/medical/dicom/2011/ The latest DICOM specification]
- DICOM Standard Status (approved and proposed changes)
- Brief introduction to DICOM
- Introduction to DICOM using OsiriX
- Medical Image FAQ part 2 - Standard formats including DICOM.
- Medical Image FAQ part 8 - Contains a long list DICOM software.
- Collection of DICOM images (clinical images and technical testpatterns)
- Example of an applet based DICOM Viewer