Foreign Exam Management Direct Import- Proposal

From IHE Wiki
Jump to navigation Jump to search


1. Proposed Workitem: Foreign Exam Management - Direct Import

  • Proposal Editor: Teri Sippel Schmidt
  • Proposal Contributors: David Koff, MD
  • Editor: Teri Sippel Schmidt
  • Contributors: David Koff, MD; Canada Health Infoway
  • Domain: Radiology


2. The Problem

A definition: "Foreign Exam Management- Direct Import" (FEM-DI) - Foreign Exam Management Direct Import is the process of taking radiologic studies performed at one site or institution and properly and directly integrating those studies into the "local PACS" at a different site or institution's PACS such that a the studies appear as a proper "prior study" in the same patient folder such that direct comparisons may be made by the radiologist in a timely manner. Note that with FEM-DI there are no CD/DVDs involved (please reference IRWF.b for CD/DVD import).

Overview of clinical problem:

Over time, patients may receive radiology and/or other studies at many various sites which may or may not be part of the same IDN or "affinity domain". However, these other studies are often "locked away" and inaccessible on a PACS system at a different institution, or even just a different site within the same institution. In other words, radiologic prior studies created at a foreign site should appear seamlessly for the radiologist in the local PACS for participating institutions, without the use of CD/DVDs.

Often, these previous studies, called "priors", have significant/irreplacable clinical value. The reading radiologist may change a diagnosis or recommendation based on this historical information.

"The redistribution of medical care into centers of excellence providing centralized specialized care to larger service areas has improved patient outcomes and standardized treatments leading to better patient outcomes. (Stitzenberg et al. 2009) One consequence of this redistribution of care has been the increased flow of patients from peripheral clinics and hospitals to larger tertiary and quaternary care centers with referrals for specialist assessment. " (quoted from SPIE paper)

Today, these prior imaging studies may be shared via:

  • patient portals
  • web-based viewers
  • CD/DVD imports
  • other methods

Issues with these methods include login/display time, access issues, direct comparison viewing (e.g., different Patient ID/patient folders), inappropriate hanging protocols (time issue), CD/DVD import issues, inappropriate display tools or hanging protocols, etc. The patient may also be re-imaged as a result.


3. Key Use Case

Detailed common clinical use case:

Assumption: A regional or Integrated Delivery Network (IDN) has implemented a Diagnostic Imaging Repository (DI-r) or Vendor Neutral Archive (VNA) for the storage and archiving of images. This DI-r/VNA stores studies as they are received (without DICOM or other attribute modifications). Alternatively, the studies may not be centrally archived, but there may be direct and secure access to any PACS system on the network via DICOM DIMSE Services.


Dr. X., a radiologist at a busy Cancer Centre, is reporting a large number of CT studies which require comparison to previous imaging often performed at remote, but secure network connected, sites in the region, mostly community hospitals, but also academic centres where the patient may have been seen. The radiologist has to evaluate changes over time in order to assess treatment efficiency, with previous performed usually 3 to 6 months earlier. There may be a series of previous studies at the same interval over a period of a few years.

Dr. X. needs to report on a lesion’s change in size and appearance, as well as interval development or resolution of other conditions such as metastatic disease, peritoneal seeding or pleural effusions. For accuracy and speed, Dr X has to be able to cross-reference his CT slices and MPRs in DICOM format, using his own measurement tools.

Dr. X. wants the remote CT(s) to be readily available in his patient folder on his own PACS, and the studies displayed using his hanging protocols. He wants the report to be available the same way he displays previous reports for studies performed in his institution.

The last thing Dr. X. wants is to have to access a separate website even if it was to use a single sign-on. He doesn’t want to have to search a separate database, he doesn’t want to wait for images to load as it will slow him down too much through his very busy work day. To make things worse, Dr. X may have to open two separate web interfaces, one for the images, another one for the report, as the DI-r/VNA may not be able to move the report with the images.

Today and in the past, even if all studies are all stored on a central DI-r/VNA or there is access to other DICOM PACS systems, Dr. X. will have to ask the remote site to print a CD/DVD with the images. He will then ask his PACS team to upload these images into his local PACS to make sure that images are available when he reports the current study. Not only is this a tedious manual process, but it will defer the time the study is reported sometimes up to a few days. And, using the CD/DVD method, it is common that the previous report is not available.


See also: Foreign_Exam_Management_-_Detailed_Proposal#3.2_Handling_Prior_Study_Pre-fetched_Over_the_Network

4. Standards and Systems

Real World Affected Systems (IHE Actor Name):

  • EMPI (Patient Identification -PIX/PDQ Manager)
  • RIS/EMRs - an system which creates orders (DSS/OF)
  • VNA or DIr (Image Archives)
  • PACS (Image Managers/Image Archives)
  • new actor - FEM Manager which may or may not be integrated into another real world system (ie., part of the EMR, part of the VNA, part of a workflow management system, or possibly stand alone system)


Standards to be used:

  • Existing profiles referenced-although the following profiles will be referenced, these profiles would not be directly affected (ie., no changes anticipated to existing profiles) These interactions may also be discussed in the Cross Profile Considerations section:
  • PIX/PDQ
  • SWF.b
  • XDS.b/XDS.b-I
  • MDH/MDH-I
  • IRWF.b
  • IOCM

More specifically, the profiles will be referred to for:

  • patient identification - PIX/PDQ as a client (reference PIX/PDQ profiles/transactions)
  • orders - access to orders for new studies at the local site would be preferable - HL7 v2.x ORM (as defined in SWF.b, pointer)
  • ad hoc queries for studies across the enterprise (federated query) needs to be discussed as to scope - DICOM Q/R or more broad support
  • image retrieval - various methods including XDS.b-I, DICOM C-Store, DICOM web services possible (pointers to various IHE Rad transactions)
  • DICOM attribute mapping - references to IRWF.b
  • image storage - DICOM C-Store to Image Manager would be the default method to send the study to the local PACS, possibly expand beyond the default option
  • report retrieval - various options to retrieve a report depending on the source,specifically receive an HL7 v2.x ORU or use MHD or XDS.b as an option
  • report attribute mapping - consistent with intent to IRWF.b for DICOM attributes
  • report storage - HL7 v2.x ORU as a default, but consider expanding to MHD and XDS.b as options


We recommend a discussion of how FHIR and DICOM web services could be integrated in the future, but limit the required transactions to the majority of the real-world installed base (ie., HL7 v2.x and DICOM).

5. Discussion

Scope/assumptions:

  • Secure network already in place between facilities. (Cross- non-affiliated enterprises out of scope.)
  • EMPI (PIX/PDQ) already in place between facilities.
  • The current scope would limit required transactions to DICOM study import into the local PACS. (ie., not direct XDS import to the PACS, although XDS or web services could be an optional transport mechanism/transaction)
  • Other image types such as Raw JPEG, PDF, etc., are out of scope.
  • Orders may or may not (although highly recommended) be created in advance for all new radiology studies at the "local" site.
  • Report content is out of scope, i.e., structured or unstructured, text or xml, etc. This could cause non-interoperability (unable to view), but is still out of scope and must be managed locally.


Definition required in this profile:

  • Federated query across PACS (across EMPI) would be useful but scope needs to be considered.
  • The foreign exam must appear as historic prior during the reporting session (same patient folder). This means reconciliation of different patient identifiers, standardization of procedures and terminology in HL7 and DICOM. See IRWF.b for information.
  • The local PACS must present the foreign exam(s) using the local hanging protocols to be displayed seamlessly side by side with the current exam.
  • The local PACS must not re-archive a foreign exam to the Diagnostic Imaging repository/VNA and no change or alteration (new measurements or post processing) to the foreign exam will be stored.
  • The local PACS should only store the foreign exam temporarily in the cache and will notify the DI-r/VNA when the foreign exam is purged.


More background here:
Retrieved from "http://wiki.ihe.net/index.php?title=Foreign_Exam_Management_Direct_Import-_Proposal&oldid=96216"