Vista Imaging Vista Routing Additional Routing Considerations, Factors Affecting Routing Speed

Additional Routing Considerations

Transmission Processors and Drive Mapping

For each Imaging destination that it sends exams to, the transmission processor will map a drive using the following progression of drive letters: Q – Z, then G – P. If a drive letter (Q, for example) is not available, it will move to the next letter (R, for example) and so on. When all entries for a particular destination have been processed, the applicable drive is unmapped. This logic is not used for DICOM destinations.

Factors Affecting Routing Speed

Given a T1 connection and a light to moderate amount of network traffic, the first images in a routed exam will typically begin arriving at a destination within minutes. However, any of the following can impact the delivery of routed exams:

ƒA backlog of images at the Image Gateway, which is responsible for adding entries to the rule evaluation queue.

ƒA backlog of entries in the transmission queue. If numerous large exams are flagged for routing in a brief period of time, there will be a delay while all the images in the exam are transmitted. In situations where multiple destinations are being used, additional transmission processors may be used to alleviate delays. For more information, see page 51.

ƒProblems connecting to destinations. For Imaging destinations, the routing software will attempt to re-connect or retransmit the number of times specified for each destination in the NETWORK LOCATION File (#2005.2). For DICOM destinations, retry attempts are part of the DICOM transmission protocol. Failed connection or transmission attempts are logged by the Routing Gateway.

ƒThe routing priority of a particular exam. For more information, see page 67.

Routed Images vs. Routed Exams

The Routing Gateway evaluates and transmits data on an image-by-image basis. If the transmission processor is disabled when an exam is partially transmitted, the exam is usually treated as “unrouted” until the transmission processor is re-started, and the transmission of the exam is completed.

In some situations, such as the presence of multiple Image Gateways or the use of on-demand routing, images from one exam will “interrupt” the transmission of images of an exam that is partially routed. This can occur because entries are added to the rule evaluation and transmission queues for each image, rather than for each exam. Usually, this behavior is invisible to the end user.

If a partially routed exam is opened from VistARad, the VistARad software will first attempt to retrieve images from the local storage location identified in the MAGJ.INI file