pynetdicom 1.3.1

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 and -N services (see the DICOM Standard Part 7, Sections 7.5, 9, and 10).

Documentation

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

Installation

$ pip install pynetdicom

$ 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 bind a handler to the evt.EVT_C_ECHO event 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. In the next example we’ll create a non-blocking Verification SCP and bind a handler for the C-ECHO service request event evt.EVT_C_ECHO that logs the requestor’s address and port number and the timestamp for the event.

import logging

from pynetdicom import AE, evt, VerificationPresentationContexts, debug_logger

# Setup logging to use the StreamHandler at the debug level
debug_logger()
LOGGER = logging.getLogger('pynetdicom')

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

# Implement the EVT_C_ECHO handler
def handle_echo(event):
    """Handle a C-ECHO service request.

    Parameters
    ----------
    event : evt.Event
        The C-ECHO service request event.

    Returns
    -------
    int or pydicom.dataset.Dataset
        The status returned to the peer AE in the C-ECHO response.
        Must be a valid C-ECHO status value as either an ``int`` or a
        ``Dataset`` object containing an (0000,0900) *Status* element.
    """
    # Every *Event* includes `assoc` and `timestamp` attributes
    #   which are the *Association* instance the event occurred in
    #   and the *datetime.datetime* the event occurred at
    requestor = event.assoc.requestor
    timestamp = event.timestamp.strftime("%Y-%m-%d %H:%M:%S")
    msg = (
        "Received C-ECHO service request from ({}, {}) at {}"
        .format(requestor.address, requestor.port, timestamp)
    )
    LOGGER.info(msg)

    # Return a *Success* status
    return 0x0000

handlers = [(evt.EVT_C_ECHO, handle_echo)]

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

# 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()