Architecture

Architecture

Components

• webui/app.py: Flask management interface for configuration, plugins, tests, logs, and lifecycle control.
• mwl_service.py: DICOM MWL SCP and database-to-DICOM mapping.
• mpps_service.py: optional DICOM MPPS SCP.
• mpps_actions.py: MPPS event/status filtering and API/SQL actions.
• dicom_printer_service.py: optional DICOM Print receiver and worker.
• flow.py: CLI, process ownership, locks, and runtime state.
• config.json: local environment configuration.
• mpps-actions/*.json: local MPPS action definitions.

Runtime state is isolated per installation under the platform-specific FlowWorklist application-data directory to prevent process conflicts between copies.

MWL and MPPS workflow

HIS / RIS database
      |
      | 1. configured worklist query
      v
FlowWorklist MWL SCP
      ^                    Imaging modality
      | 2. C-FIND request         |
      +---------------------------+
      |
      +---- 3. scheduled procedure C-FIND responses ---->

Imaging modality
      |
      | 4. N-CREATE: procedure started
      | 5. N-SET: procedure status updated/completed
      v
FlowWorklist MPPS SCP
      |
      | 6. normalize DICOM payload
      | 7. evaluate enabled event and status filters
      v
Configured action
      +--> HTTP API
      +--> SQL statement
      +--> API and SQL
      +--> skipped when no action matches

The MWL response does not directly invoke MPPS. The modality consumes a scheduled procedure from MWL and later sends independent MPPS messages. Accession number, patient ID, requested procedure ID, and study identifiers can correlate the two workflows.

Failure boundaries

• A database failure prevents MWL query responses but should not expose credentials to the modality.
• An MPPS action failure is logged after the MPPS event is received; action filters should be explicit and actions should be idempotent.
• The management UI supervises child services only when configured to do so.
• DICOM Print is optional and independent from MWL and MPPS.

See Production Deployment for process ownership and network policy.