pynetdicom 1.2.0

A Python implementation of the DICOM networking protocol

pynetdicom

A Python implementation of the DICOM networking protocol, originally based on (legacy) pynetdicom.

Description

DICOM is the international standard for medical images and related information. It defines the formats and communication protocols for media exchange in radiology, cardiology, radiotherapy and other medical domains.

pynetdicom is a pure Python (2.7/3.4+) package that implements the DICOM networking protocol. Working with pydicom, it allows the easy creation of DICOM Service Class Users (SCUs) and Service Class Providers (SCPs).

The main user class is AE, which is used to represent a DICOM Application Entity. Once the AE has been created you would typically either:

• Start the application as an SCP by specifying the presentation contexts that you will support, then calling AE.start_server((host, port)) and waiting for incoming association requests

• Use the application as an SCU by specifying the presentation contexts you want the peer SCP to support, then requesting an association via the AE.associate(host, port) method, which returns an Association thread.

Once the application is associated with a peer AE, DICOM data can be sent between them by utilising the DIMSE-C services (see the DICOM Standard Part 7, Sections 7.5, and 9).

Supported Service Classes

pynetdicom supports the following DICOM service classes:

• Verification Service Class

• Storage Service Class

  • Softcopy Presentation State Storage

  • Structured Reporting Storage

  • Ophthalmic Refractive Measurements Storage

  • Volumetric Presentation State Storage

• Query/Retrieve Service Class

  • Instance and Frame Level Retrieve

  • Composite Instance Retrieve Without Bulk Data

• Basic Worklist Management Service Class

• Relevant Patient Information Query Service Class

• Hanging Protocol Query/Retrieve Service Class

• Substance Administration Query Service Class

• Color Palette Query/Retrieve Service Class

• Implant Template Query/Retrieve Service Class

• Display System Management Service Class

• Non-Patient Object Storage Service Class

• Defined Procedure Protocol Query/Retrieve Service Class

Supported DIMSE SCU Services

When the AE is acting as an SCU and an association has been established with a peer SCP, the following DIMSE-C and -N services are available (provided the peer supports the Service Class corresponding to the dataset and a corresponding Presentation Context has been accepted):

• C-ECHO: Association.send_c_echo() used to verify end-to-end communications with the peer.

• C-STORE: Association.send_c_store(dataset) requests the storage of the Composite SOP Instance dataset by the peer.

• C-FIND: Association.send_c_find(dataset) requests the peer search its set of managed SOP Instances for those that match the attributes given in dataset.

• C-GET: Association.send_c_get(dataset) requests the peer search its set of managed SOP Instances for those that match the attributes given in dataset then return those matching Instances to the SCU.

• C-MOVE: Association.send_c_move(dataset, move_aet) requests the peer search its set of managed SOP Instances for those that match the attributes given in dataset and then copy those matching Instances to the AE with title move_aet over a new association.

• N-EVENT-REPORT: Association.send_n_event_report(dataset, event_type, class_uid, instance_uid) reports the events in dataset to the peer.

• N-GET: Association.send_n_get(identifier_list, class_uid, instance_uid) requests the retrieval of attribute values from a peer.

• N-SET: Association.send_n_set(dataset, class_uid, instance_uid) requests the peer modify a SOP Instance using the attribute values in dataset.

• N-ACTION: Association.send_n_action(dataset, action_type, class_uid, instance_uid) requests the peer perform an action.

• N-CREATE: Association.send_n_create(dataset, class_uid, instance_uid) requests the peer create a new SOP Instance.

• N-DELETE: Association.send_n_delete(class_uid, instance_uid) requests the peer delete the specified SOP Instance.

Where dataset is a pydicom Dataset object, identifier_list is a list of pydicom Tag objects, event_type and action_type are ints and class_uid and instance_uid are UID strings.

Supported DIMSE SCP Services

When the AE is acting as an SCP the following DIMSE-C and -N services are available to the peer once an association has been established. With the exception of on_c_echo(), the user is expected to handle the required operations by implementing one (or more) of the following AE callbacks:

• C-ECHO: AE.on_c_echo(context, info)

• C-STORE: AE.on_c_store(dataset, context, info)

• C-FIND: AE.on_c_find(dataset, context, info)

• C-GET: AE.on_c_get(dataset, context, info)

• C-MOVE: AE.on_c_move(dataset, move_aet, context, info)

• N-GET: AE.on_n_get(attr, context, info)

Where dataset is a pydicom Dataset object, context is a namedtuple with details of the Presentation Context used to transfer dataset, info is a dict containing information about the association and the message request (such as the peer’s IP address and AE title and the message priority), move_aet is the Move Destination AE title and attr is a list of pydicom Tag objects.

Documentation

The pynetdicom user guide, code examples and API reference documentation is available for the current release as well as the development version.

Installation

Dependencies

pydicom

Installing current release

$ pip install pynetdicom

Installing development version

$ pip install git+git://github.com/pydicom/pynetdicom.git

Examples

Send a DICOM C-ECHO to a peer Verification SCP (at TCP/IP address addr, listen port number port):

from pynetdicom import AE

ae = AE(ae_title=b'MY_ECHO_SCU')
# Verification SOP Class has a UID of 1.2.840.10008.1.1
#   we can use the UID string directly when requesting the presentation
#   contexts we want to use in the association
ae.add_requested_context('1.2.840.10008.1.1')

# Associate with a peer DICOM AE
assoc = ae.associate(addr, port)

if assoc.is_established:
    # Send a DIMSE C-ECHO request to the peer
    # `status` is a pydicom Dataset object with (at a minimum) a
    #   (0000,0900) Status element
    # If the peer hasn't accepted the requested context then this
    #   will raise a RuntimeError exception
    status = assoc.send_c_echo()

    # Output the response from the peer
    if status:
        print('C-ECHO Response: 0x{0:04x}'.format(status.Status))

    # Release the association
    assoc.release()

Create a blocking DICOM C-ECHO listen SCP on port 11112 (you may optionally implement the AE.on_c_echo callback if you want to return something other than a Success status):

from pynetdicom import AE, VerificationPresentationContexts

ae = AE(ae_title=b'MY_ECHO_SCP')
# Or we can use the inbuilt VerificationPresentationContexts list,
#   there's one for each of the supported Service Classes
# In this case, we are supporting any requests to use Verification SOP
#   Class in the association
ae.supported_contexts = VerificationPresentationContexts

# Start the SCP on (host, port) in blocking mode
ae.start_server(('', 11112), block=True)

Alternatively, you can start the SCP in non-blocking mode, which returns the running server instance. This can be useful when you want to run a Storage SCP and make C-MOVE requests within the same AE:

from pynetdicom import AE, VerificationPresentationContexts

ae = AE(ae_title=b'MY_ECHO_SCP')
ae.supported_contexts = VerificationPresentationContexts

# Start the SCP in non-blocking mode
scp = ae.start_server(('', 11112), block=False)

# Let's send a C-ECHO request to our own Verification SCP
ae.add_requested_context('1.2.840.10008.1.1')
assoc = ae.associate('localhost', 11112)
if assoc.is_established:
    status = assoc.send_c_echo()
    assoc.release()

# Shutdown the SCP
scp.shutdown()

Send the DICOM ‘CT Image Storage’ dataset in file-in.dcm to a peer Storage SCP (at TCP/IP address addr, listen port number port):

from pydicom import dcmread
from pydicom.uid import ImplicitVRLittleEndian

from pynetdicom import AE, VerificationPresentationContexts
from pynetdicom.sop_class import CTImageStorage, MRImageStorage

ae = AE(ae_title=b'MY_STORAGE_SCU')
# We can also do the same thing with the requested contexts
ae.requested_contexts = VerificationPresentationContexts
# Or we can use inbuilt objects like CTImageStorage.
# The requested presentation context's transfer syntaxes can also
#   be specified using a str/UID or list of str/UIDs
ae.add_requested_context(CTImageStorage,
                         transfer_syntax=ImplicitVRLittleEndian)
# Adding a presentation context with multiple transfer syntaxes
ae.add_requested_context(MRImageStorage,
                         transfer_syntax=[ImplicitVRLittleEndian,
                                          '1.2.840.10008.1.2.1'])

assoc = ae.associate(addr, port)
if assoc.is_established:
    dataset = dcmread('file-in.dcm')
    # `status` is the response from the peer to the store request
    # but may be an empty pydicom Dataset if the peer timed out or
    # sent an invalid dataset.
    status = assoc.send_c_store(dataset)

    assoc.release()