DICOM Modality Types: The Complete List of Codes

DICOM modality codes are the short, standardized values, such as CT, MR, and US, that identify the type of equipment, process, or method that created a series of images or documents. They are stored in the Modality tag (0008,0060) of every DICOM file, and PACS, viewers, and worklists rely on them to filter, route, and display studies consistently across devices and vendors.

This article will uncover the significance of DICOM modality types and their role in medical imaging workflows.

What is DICOM Modality?

DICOM, or Digital Imaging and Communications in Medicine, is the global standard for managing medical images. A DICOM modality is the type of imaging device or process used, such as Computed Radiography (CR), Magnetic Resonance (MR), or Ultrasound (US). Some codes describe a type of object rather than a device, such as SR for structured reports or SEG for segmentations.

Each modality is assigned a unique identifier, ensuring consistent categorization and seamless integration across the healthcare system.

DICOM modalities are labels that define imaging procedures. They help healthcare professionals organize, retrieve, and share imaging data effectively. By standardizing communication, DICOM makes it easier for different devices and systems, including PACS, HIS, and RIS, to work together.

It helps systems file, filter, and route studies consistently, reducing manual categorization errors.

DICOM Modality Types: The Full List of Radiology Modalities and Codes

A standard naming system helps organize and share medical imaging data consistently across healthcare platforms. This improves communication between systems and makes patient care more efficient.

The table below is the complete list of DICOM modality codes, the standardized radiology modalities used across imaging systems, with each code and its description.

Complete current DICOM Modality codes (PS3.3 2026d, C.7.3.1.1.1)

Modality Code	Description
ANN	Annotation
AR	Autorefraction
ASMT	Content Assessment Results
AU	Audio
BDUS	Bone Densitometry (ultrasound)
BI	Biomagnetic Imaging
BMD	Bone Densitometry (X-ray)
CFM	Confocal Microscopy
CR	Computed Radiography
CT	Computed Tomography
CTPROTOCOL	CT Protocol (Performed)
DMS	Dermoscopy
DG	Diaphanography
DOC	Document
DX	Digital Radiography
ECG	Electrocardiography
EEG	Electroencephalography
EMG	Electromyography
EOG	Electrooculography
EPS	Cardiac Electrophysiology
ES	Endoscopy
FID	Fiducials
GM	General Microscopy
HC	Hard Copy
HD	Hemodynamic
IO	Intra-Oral Radiography
IOL	Intraocular Lens Data
IVOCT	Intravascular Optical Coherence Tomography
IVUS	Intravascular Ultrasound
KER	Keratometry
KO	Key Object Selection
LEN	Lensometry
LS	Laser Surface Scan
MG	Mammography
MR	Magnetic Resonance
M3D	Model for 3D Manufacturing
NM	Nuclear Medicine
OAM	Ophthalmic Axial Measurements
OCT	Optical Coherence Tomography (non-Ophthalmic)
OP	Ophthalmic Photography
OPM	Ophthalmic Mapping
OPT	Ophthalmic Tomography
OPTBSV	Ophthalmic Tomography B-scan Volume Analysis
OPTENF	Ophthalmic Tomography En Face
OPV	Ophthalmic Visual Field
OSS	Optical Surface Scan
OT	Other
PA	Photoacoustic
PLAN	Plan (planned activities; not radiotherapy plans, which use RTPLAN)
POS	Position Sensor
PR	Presentation State
PT	Positron Emission Tomography (PET)
PX	Panoramic X-Ray
REG	Registration
RESP	Respiratory
RF	Radio Fluoroscopy
RG	Radiographic Imaging (conventional film/screen)
RTDOSE	Radiotherapy Dose
RTIMAGE	Radiotherapy Image
RTINTENT	Radiotherapy Intent
RTPLAN	Radiotherapy Plan
RTRAD	RT Radiation
RTRECORD	RT Treatment Record
RTSEGANN	Radiotherapy Segment Annotation
RTSTRUCT	Radiotherapy Structure Set
RWV	Real World Value Map
SEG	Segmentation
SM	Slide Microscopy
SMR	Stereometric Relationship
SR	SR Document
SRF	Subjective Refraction
STAIN	Automated Slide Stainer
TEXTUREMAP	Texture Map
TG	Thermography
US	Ultrasound
VA	Visual Acuity
XA	X-Ray Angiography
XAPROTOCOL	XA Protocol (Performed)
XC	External-camera Photography

Retired DICOM Modality codes

DICOM has retired 18 older modality codes. New systems should not create them, but they still appear in studies stored years ago, so archives, migrations, and queries need to recognize them. Several were folded into current codes: SPECT studies, for example, are now coded NM, and echocardiography is coded US.

Retired Code	Description	Now covered by
AS	Angioscopy	Not specified in the standard
CD	Color flow Doppler	US
CF	Cinefluorography	RF
CP	Colposcopy (spelled “Culposcopy” in the standard)	Not specified in the standard
CS	Cystoscopy	Not specified in the standard
DD	Duplex Doppler	US
DF	Digital fluoroscopy	RF
DM	Digital microscopy	Not specified in the standard
DS	Digital Subtraction Angiography	XA
EC	Echocardiography	US
FA	Fluorescein angiography	Not specified in the standard
FS	Fundoscopy	Not specified in the standard
LP	Laparoscopy	Not specified in the standard
MA	Magnetic resonance angiography	MR
MS	Magnetic resonance spectroscopy	MR
OPR	Ophthalmic Refraction	Not specified in the standard
ST	Single-photon emission computed tomography (SPECT)	NM
VF	Videofluorography	RF

Source: DICOM PS3.3 2026d, Section C.7.3.1.1.1, Retired Defined Terms and Notes 1, 2, 4, 5, and 6.

The DICOM Modality Tag (0008,0060)

DICOM tag (0008,0060) Modality stores the modality code for a Series in DICOM metadata. DICOM Modality tag values like CT, MR, US, CR, DX, OT, SR, and PR let PACS, VNA, and DICOM viewers filter and route studies by modality without guessing.

The Modality tag (0008,0060) describes the type of device, process, or method that created the instances in a series.

Modality values follow the Defined Terms listed in DICOM PS3.3, Section C.7.3.1.1.1, and they do not always match the IOD name you might expect. The standard gives an example: an image created under the X-Ray Angiographic Image IOD may list RF as its modality when it comes from a fluoroscopy system. Modality-based routing rules therefore need to be tested against real data.

The most common examples of this in practice are non-acquisition objects: SR (Structured Report) documents, PR (Presentation State) objects, KO (Key Object Selection) documents, and SEG (Segmentation) instances, all carry modality codes in (0008,0060) that describe their content type rather than the imaging device that produced them. A PACS routing rule that filters by modality code will see these objects alongside CT and MR studies, which is why modality-based routing rules require explicit handling for non-image SOP classes.

DICOM modality abbreviations that matter most in daily radiology workflows include:

• CT, Computed Tomography
• MR, Magnetic Resonance
• US, Ultrasound
• CR, Computed Radiography
• DX, Digital Radiography
• NM, Nuclear Medicine
• PT, PET
• XA, X-Ray Angiography
• OT, Other

DICOM defines many more modality codes, and the code table above serves as a reference list of DICOM modality codes.

In a cloud PACS such as Medicai, modality codes help users filter and find studies across sites.

Applications of DICOM Modality Types

Various medical specialties use DICOM modality types. Major applications include:

• Radiology: X-rays, CT scans, and MRIs for diagnosing fractures, infections, and internal injuries.
• Cardiology: Echocardiograms and angiograms to evaluate heart function and blood flow
• Oncology: Modalities like PET scans and radiotherapy imaging to track tumor progression and plan treatment
• Pediatrics: Modalities with low radiation exposure, such as ultrasound or specialized X-rays
• Telemedicine: Remote access and sharing of imaging data for consultations and diagnosis

Why DICOM Modality Types Matter

DICOM modality types are more than just labels — they are the foundation of interoperability in medical imaging. Each categorized imaging procedure, identified by a standard identifier, ensures that data is shared and interpreted consistently across different systems and devices.

Let’s look at the benefits of DICOM Modality Types in diagnostic imaging

Interoperability

Modality codes help systems from different manufacturers categorize and route studies consistently, which is one building block of interoperability.

Standardization

DICOM modality types provide a universal standard for categorizing imaging procedures. This consistency helps devices, systems, and software to work together without compatibility issues.

Efficiency

DICOM modalities reduce the time spent managing imaging data, allowing healthcare providers to focus on diagnosing and treating patients.

Data Integrity

Consistent modality coding helps studies reach the right worklists, viewers, and archives and makes categorization errors easier to detect.

What Is the DICOM Modality Worklist?

The DICOM modality worklist (MWL) is a powerful tool that automates the flow of patient and study data between medical imaging systems and devices. It streamlines imaging workflows by integrating with healthcare systems like Radiology Information Systems (RIS) and Hospital Information Systems (HIS).

The connection between DICOM modality codes and MWL is direct and operational. When an imaging device queries the MWL server for its scheduled patients, it can include its modality code as one of the C-FIND matching keys. If it does, the RIS returns only scheduled procedure steps with that modality. A scheduled exam recorded in RIS as modality “MR” will not be returned to a CT scanner querying with modality code “CT,” even if the patient name, date, and AE title all match. This is why the Modality field in tag (0008,0060) is not just a display and routing label — it can also act as a filter that determines whether a scheduled exam appears on a scanner’s worklist.

The worklist ensures that imaging orders and patient details are communicated effortlessly.

MWL also eliminates the need for manual data entry. It pulls patient demographics, study details, and imaging orders from the RIS and HIS to ensure imaging devices have accurate, consistent data for every procedure.

This integration minimizes errors, speeds up processes, and enhances overall efficiency in the diagnostic imaging workflow.

DICOM modality worklist standard, PS3.4, and the MWL SOP Class

DICOM Modality Worklist is standardized in DICOM PS3.4 under the Basic Worklist Management Service Class. DICOM PS3.4 defines the Modality Worklist SOP Class and the Modality Worklist Information Model that acquisition systems query to retrieve Scheduled Procedure Step details.

DICOM Modality Worklist works as a query service, not a file export. DICOM Modality Worklist queries use C-FIND against the Modality Worklist Information Model, and the MWL server returns one response per matching worklist item.

DICOM Modality Worklist Wikipedia pages exist and help non-technical readers, but DICOM PS3.4 remains the normative source for MWL behavior, identifiers, and required attribute semantics.

DICOM modality worklist client and server, SCU vs SCP

DICOM modality worklist client software runs on the acquisition modality as an SCU (Service Class User). DICOM modality worklist server software runs as an SCP (Service Class Provider), often integrated with RIS, an interface engine, or an imaging workflow platform.

The DICOM Modality Worklist request flow follows a single pattern.

1. The modality worklist DICOM client sends a C-FIND query to the MWL SCP.
2. The MWL SCP returns matching Scheduled Procedure Steps as C-FIND responses.
3. The modality console uses the returned demographics and procedure details to prevent retyping and mismatches.

Enterprise DICOM modality worklist deployments centralize MWL SCP services, so multi-site modality fleets pull from a single, governed source with consistent configuration and monitoring. A centralized worklist becomes essential when dozens of scanners and multiple RIS sources are involved.

How Does the DICOM Modality Worklist Work?

The DICOM Modality Worklist automates and organizes imaging workflows. Here’s how it works step-by-step.

Retrieving Patient Information

The worklist provider, usually the RIS, holds the patient demographics and study details for each scheduled exam. It includes:

• Patient names
• IDs
• Scheduled procedures
• Imaging requirement.

Automatic Scheduling

Imaging devices such as CT and MRI scanners query the worklist and load each patient’s details and imaging instructions. These machines are set up with the patient’s specific information and the necessary imaging instructions. It eliminates manual data entry, reduces errors, and saves time.

Delivery to Imaging Modalities

The worklist response gives the technologist the correct patient and procedure details at the scanner. It confirms the technicians have the correct details before starting the procedure, streamlines preparation, and enhances workflow efficiency.

Execution and Data Feedback

After the scan, the modality sends the images to PACS and, if supported, reports the procedure as complete via Modality Performed Procedure Step (MPPS). Medicai enhances MWL by integrating secure cloud storage solutions. It provides real-time updates, reduces errors, and enables seamless sharing of imaging results.

DICOM modality worklist example, C-FIND query, and return keys

DICOM modality worklist example queries use C-FIND to retrieve one worklist item per Scheduled Procedure Step. DICOM PS3.4 describes the MWL C-FIND identifier and the attributes that act as matching keys and return keys.

DICOM modality worklist example: simple “today’s CT list for one scanner”.

• Matching key: Scheduled Procedure Step Start Date inside Scheduled Procedure Step Sequence
• Matching key: Scheduled Station AE Title for the scanner AET
• Matching key: Modality (0008,0060) set to CT
• Return keys: Patient Name, Patient ID, Accession Number, Requested Procedure ID, Scheduled Procedure Step Start Time

DICOM modality worklist query tool output returns one response per matching scheduled step, so a busy CT room sees a list, not one giant payload.

DICOM modality worklist query tool options are available to both IT teams and developers.

• DCMTK findscu works as a modality worklist DICOM SCU for C-FIND testing against MWL SCP endpoints.
• FO-DICOM exposes DicomCFindRequest for C-FIND modality worklist queries inside .NET applications and integration services.

DICOM modality worklist definition stays consistent across implementations. The DICOM modality worklist provides scheduled procedure step details to imaging modalities, reducing manual typing and improving patient safety.

Challenges In Managing DICOM Modality Types

Managing modality codes and worklists comes with practical challenges.

• Complex Integration: It requires powerful IT support as healthcare facilities often use devices and systems from different manufacturers, leading to integration issues.
• Regular Compliance: DICOM data must comply with privacy laws like HIPAA to ensure secure storage and transfer of sensitive patient information.
• Technical Maintenance: Configuring and maintaining the modality worklist can be resource-intensive, especially when IT infrastructure is limited.

DICOM modality worklist tester tools, modality emulators, and MWL servers

DICOM modality worklist tester tools reduce MWL integration failures by validating MWL responses before connecting to a live RIS. DICOM modality emulator tools simulate modality behavior, and MWL servers simulate RIS behavior, so technicians and PACS admins test edge cases without risking production scheduling.

Free DICOM modality worklist servers and open-source options cover three common needs.

DICOM modality worklist server, file-based MWL SCP for quick testing

• DCMTK wlmscpfs implements a Basic Worklist Management SCP and listens for MWL C-FIND requests.
• Orthanc sample worklists plugin mimics wlmscpfs behavior by serving worklists stored in a filesystem folder.

Enterprise DICOM modality worklist server, MWL SCP integrated with orders and workflow

dcm4chee includes a Modality Worklist SCP and manages worklist entries that tie into HL7 orders in typical enterprise setups.

DICOM modality worklist tester and modality emulator, tooling for QA and integration testing

DVTk RIS Emulator emulates a RIS worklist source using the Modality Worklist Information Model, and logs requests and responses for debugging.

DICOM modality worklist software selection stays simple when you align tools to the question.

• MWL server open source, DCMTK wlmscpfs or dcm4chee MWL SCP.
• DICOM modality worklist query tool, DCMTK findscu, or FO-DICOM C-FIND request objects.
• DICOM modality worklist tester, DVTk RIS Emulator for repeatable scenario testing.

Several strategies help:

• Advanced IT support to manage integration and troubleshooting
• Cloud-based platform for scalability, security, and easy access to manage DICOM modalities.
• Regular training is needed to inform staff about the capabilities and limitations of DICOM modalities.

How the MWL C-FIND query works end-to-end, which DICOM attributes the scanner sends and the RIS must return, what breaks when those attributes are mismatched, and how MPPS closes the acquisition loop after the scan is complete are covered in full in the DICOM Modality Worklist guide.

Take Away

DICOM modality types ensure seamless communication and integration across diverse devices and systems. They enable efficient workflow, accurate diagnoses, and enhanced collaboration among healthcare professionals through standardized categorization and sharing.

A cloud platform like Medicai helps teams find, share, and route studies by modality across sites. Real-time access, secure data sharing, and streamlined workflow transform the imaging process, helping providers focus on what truly matters—exceptional patient care.

Sources

The modality codes and worklist details in this guide are based on the official DICOM Standard, published by NEMA and freely available at dicomstandard.org.

• DICOM PS3.3 2026d, Section C.7.3.1.1.1, Modality: the defined terms for the Modality tag (0008,0060), including current and retired codes, and how retired codes map to current ones. Read Section C.7.3
• DICOM PS3.6 2026d, Data Dictionary: the definition of the Modality tag (0008,0060) and all other standard data elements. Read PS3.6, Chapter 6
• DICOM PS3.4 2026d, Annex K, Basic Worklist Management Service Class: how the Modality Worklist works, including C-FIND matching keys. Read Annex K
• DICOM PS3.4 2026d, Section K.6, Modality Worklist SOP Class: the Modality Worklist information model and its attributes. Read Section K.6