dicom-send Gear

A Flywheel Gear to use pynetdicom to send DICOM data from a Flywheel instance to a DICOM server.

Description

pynetdicom is a library built on top of pydicom. The dicom-send Gear uses pynetdicom as a DICOM SCU to connect from a Flywheel instance to a specific DICOM server. The DICOM server must be reachable from the host of the Flywheel instance. Before transmitting the DICOM file, a private tag indicating the DICOM file's source as Flywheel is added to each DICOM file to avoid being re-ingested into a Flywheel instance.

Gear Inputs

Regular inputs

• file: Any DICOM file or an archive (zip or tar) containing DICOM file(s). Non DICOM files are ignored. If no input is provided, all DICOM files in the session where the Gear is executed are downloaded and used as input.

NOTE: The gear will run with a dedicated read-only API key with the same permissions as the user whio created the job.

TLS related inputs

• key: Private key used for TLS negotiation, required if the config option tls_enabled is set to enabled
• cert: Public certificate used for TLS negotiation, required if the config option tls_enabled is set to enabled
• add_cert_file: Optional TLS certificate to add to the default list of trusted certificates. If your PACS server has a self-signed sert, you should supply the root CA here, unless you have the config option tls_require_peer_cert set to False.

Configuration Settings

General configuration

• destination: The IP address or hostname of the destination DICOM server. Note: The server must be reachable from the host of the Flywheel instance.
• called_ae: The Called AE title of the receiving DICOM server.
• calling_ae: The Calling AE title. Default = flywheel.
• port: Port number of the listening DICOM service. Default = 104.
• file_download_retry_time: Max time (per file) to back-off download a file on a server error (500, 501, 502, etc.)
• group: Dicom group to apply dicom-send tag, default 0x0021.
• identifier: Private tag creator for dicom-send tag, default Flywheel.
• tag_value: Dicom tag value for dicom-send tag, default DICOM send.

TLS configuration

Note: Whatever key/cert you pass in should have been signed by a root CA that is on the list of trusted certs for your PACS server, if its not, the request will most likely be rejected.

A helpful resource is the Orthanc docs on dicom-tls

• tls_enabled: (boolean), if yes, the cert and key inputs must be passed in, and possibly the add_cert_file need to pass in a cert and key input, and possibly an add_cert_file input if your PACS server has a self-signed cert.
• tls_security_profile: Security profile to use, default BCP 195.
• tls_require_peer_cert: Require the peer server to have a valid/trusted cert. This defaults to true, but can be set to false if you trust the destination and don't want to add your root CA to the add_cert_file input.

Gear outputs

The gear will generate a report listing each dicom file/archive that was exported. The report includes the following columns:

• Acquisition ID: the FW Acquisition ID
• FW Path: a human readable flywheel path to the file that was exported, in the following format:
  • <group>/<proj.label>/<sub.label>/<ses.label>/<acq.label>/files/<file.name>
• Filename: Name of the file/archive that was sent
• Images in Series: Number of images in the series to be sent
• Images Sent: Number of images successfully sent
• Status: “Complete” if images in series == Images Sent, “Incomplete” if Images Sent < Images in Series, “Failed” if Images Sent == 0.

This report is printed at the end of the log file, and also saved as an attachment to the session container that the gear was run from. The output name of this report file follows the following pattern:

dicom-send_report-<session label>_<acquisition label>_YYYY-MM-DD_HH:MM:SS.csv where <acquisition_label> is only present if one specific acquisition was selected for export.

The gear will present as successful only if all dicoms that were attempted, were sent succesfully.

Testing

For information on gear testing, see the testing readme.