DICOMweb

Query based on ID for DICOM Objects (QIDO-RS) is the search service. It uses HTTP GET requests to query a DICOMweb server for studies, series, or instances based on DICOM tag attributes.

• Request: GET /studies?PatientName=Smith*
• Response: JSON or XML payload containing matching Study Instance UIDs.
• Function: Replaces the legacy DIMSE C-FIND command for web-based discovery.

Web Access to DICOM Persistent Objects (WADO-RS) enables the retrieval of individual DICOM instances, frames, or metadata. It uses standard HTTP GET requests with specific media types.

• Instance Retrieval: GET /studies/{uid}/series/{uid}/instances/{uid}
• Frame Retrieval: Specify a single frame from a multi-frame object.
• Media Types: Supports application/dicom+xml, application/dicom+json, and raw binary.

Store Over the Web (STOW-RS) is the service for uploading DICOM instances to a server. It uses an HTTP POST request with a multipart/related body.

• Request: POST /studies with each part containing a single DICOM SOP Instance.
• Response: An XML or JSON document detailing the success or failure of each stored instance.
• Advantage: A modern, firewall-friendly alternative to the DIMSE C-STORE command.

Web Access to DICOM Objects by URI (WADO-URI) is an older, non-RESTful service that retrieves a single DICOM object or a rendered image via a query-string-based HTTP GET request.

• Format: GET /wado?requestType=WADO&studyUID=...
• Output: Can return a JPEG-rendered image or a raw DICOM object.
• Status: Largely superseded by the more flexible WADO-RS service in modern architectures.

Unified Procedure Step (UPS-RS) is a DICOMweb service for managing imaging workflows. It allows external systems to create, claim, and complete work items via RESTful calls.

• Create: POST /workitems to define a new task (e.g., a post-processing job).
• Claim: PUT /workitems/{uid} to lock a task for a specific user or system.
• Complete: PUT /workitems/{uid} with a final status to signal task completion.

A RESTful service for retrieving DICOM instances over HTTP. It uses standard HTTP GET requests with specific media types like application/dicom+xml or application/dicom+json to fetch studies, series, or individual instances.

• Bulk Data Retrieval: Supports fetching individual frames or byte ranges from a single instance.
• Metadata Access: Allows retrieval of the DICOM header as XML or JSON without the pixel data.
• Endpoint Pattern: /studies/{StudyInstanceUID}/series/{SeriesInstanceUID}/instances/{SOPInstanceUID}

A RESTful service for searching and querying DICOM metadata. It sends an HTTP GET request with query parameters matching DICOM tags to a server and returns a JSON or XML list of matching entities.

• Hierarchical Search: Query at the Study, Series, or Instance level.
• Attribute Matching: Filter by Patient Name, Modality, Study Date, and other DICOM attributes.
• Endpoint Pattern: /studies?PatientName=Smith*&Modality=CT

A RESTful service for storing DICOM instances via HTTP. It uses a multipart/related POST request to transmit one or more DICOM files to a server, serving as the modern alternative to the legacy DIMSE C-STORE command.

• Bulk Storage: Transmit multiple SOP Instances in a single HTTP request.
• Response Payload: Returns an XML or JSON document detailing the success or failure of each stored instance.
• Endpoint Pattern: /studies (with multipart body containing DICOM files)

A RESTful service for managing workflow tasks. It allows systems to create, claim, and complete work items, such as a post-processing task or a reading assignment, using standard HTTP methods.

• Worklist Management: Query for pending tasks using a subscription mechanism.
• State Transitions: Use HTTP PUT to update the status of a work item from 'SCHEDULED' to 'IN PROGRESS' to 'COMPLETED'.
• Endpoint Pattern: /workitems/{WorkItemUID}

The specific IANA-registered media types that enable DICOMweb interoperability. They define how DICOM data is serialized for HTTP transactions, replacing the binary DICOM wire format.

• application/dicom+json: Encodes DICOM metadata as a JSON array of tag-value pairs.
• application/dicom+xml: Encodes DICOM metadata as an XML infoset.
• multipart/related; type="application/dicom": The container format for transmitting bulk DICOM instances in STOW-RS.

A comparison between the legacy stateful protocol and the modern RESTful API for medical imaging. DICOMweb was designed to overcome the firewall and complexity limitations of DIMSE.

• DIMSE: Uses a persistent, stateful TCP/IP association with binary encoding. Commands include C-STORE, C-FIND, and C-MOVE.
• DICOMweb: Uses stateless HTTP/HTTPS with JSON/XML encoding. Commands are standard HTTP methods like GET and POST.
• Key Advantage: DICOMweb traverses standard web proxies and load balancers without special configuration.