Why Should Radiologists Care about IT Standards and Interoperability?

Radiology and Information Technology‏ Have a Long History Together‏

The digitisation of imaging modalities began in‏ the 1970s with digital radiography and computed‏ tomography. This was followed in the mid-1980s by the‏ introduction of the first radiological information systems‏ (RIS). PACS (Picture Archiving and Communication‏ System) solutions have been increasingly used in‏ practice since the mid-1990s. Often, a dedicated IT‏ department has been established in radiology facilities‏ during this time. The use of IT solutions then continued‏ with speech recognition.‏

 

For about 20 years now, the topic of structured‏ reporting and clinical decision support has also been‏ a major digital development in radiology. This is also‏ reflected in an exponentially increasing number of‏ publications on these topics; a literature search in‏ PubMed, for example, yields over 16,000 hits for the topic‏ of structured reporting. And for the last few years, there‏ has been a topic that is generating even more attention in‏ radiology: artificial intelligence (AI). In 2022 alone, there‏ are already over 1,400 publications on this topic.

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Without Standards: No Inter-operability‏

It is obvious and thus easy to understand that the use‏ of such different solutions in a radiology department‏ needs certain rules. The probability that all solutions‏ can be provided by one vendor is rather low, resulting‏ in a plethora of ‘plug-and-play’ applications. Therefore,‏ standards are needed for these different issues, both‏ regarding physical connectivity and, for example, content.‏ The term inter-operability refers to the ability to connect‏ and exchange information between different healthcare‏ systems without any significant limitation in connectivity.‏

 

Which standards are relevant for radiology?‏

On the one hand, these are standards that are used‏ for the general definition of patient data or findings;‏ historically, this is associated with the term HL7. For‏ the imaging itself, the DICOM standard has been‏ established in radiology for nearly 30 years. In addition,‏ other general standards like from Internet technology,‏ play a role.‏

 

A further development is the re-naming of HL7 to‏ FHIR, and this standard is rapidly gaining in importance,‏ since it provides support for web-based and mobile‏ applications in particular.‏

 

As important and indispensable as standards are‏ in radiology, they also have their limitations. Often‏ variations, so-called options, are defined in the standard‏ and depending on how these are implemented in an‏ application, interoperability between different systems is‏ easy, limited or even impossible. One can compare the‏ implementation of standards with different gradations,‏ for example, with different dialects of a language. Even‏ if two people nominally speak the same language but‏ have very different dialects, they may not understand‏ each other. Therefore, special attention should be paid‏ to this issue. One solution is to reduce such “language‏ differences” through the use of so-called ‘integration‏ profiles’.‏

 

IHE is an international organisation that develops such‏ integration profiles for various applications, especially‏ in Radiology and in IT infrastructure. Manufacturers‏ can then refer to these IHE profiles when developing‏ their applications and submit corresponding integration‏ statements.

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A closer look at these most important areas for radiology:

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DICOM‏

The DICOM (Digital Imaging and Communications in‏ Medicine) standard is an international standard that‏ was initiated in 1993 by NEMA (National Electrical‏ Manufacturers Association) and ACR (American College‏ of Radiology) as well as the RSNA (Radiological‏ Society of North America) and is now supported‏ and co-developed by numerous other organisations,‏ including the ESR (European Society of Radiology) and‏ other national (European) societies.

 

DICOM started in‏ radiology, but is now used in many other medical fields,‏ for example ophthalmology, cardiology, pathology or‏ surgery, also with appropriate extensions.‏ DICOM is organised into so-called working groups‏ (WG), of which there are about 30. DICOM is probably‏ the most successful standard in healthcare. It is‏ accredited as a international standard by ISO under‏ the number 12052. The DICOM standard is published‏ in one version that is periodically updated. For this‏ purpose, so-called supplements are developed that are‏ later incorporated into the standard. Corrections to the‏ standard can be made by so-called Change Proposals.‏

 

DICOM has a continuous maintenance process, which is‏ ensured by WG 6. Manufacturers of IT applications must‏ publish a so-called DICOM Conformance Statement,‏ which shows the tasks of a product or software and how‏ the different options have been implemented or which‏ forms of communication are supported. Based on such‏ DICOM conformance statements, it is possible to check‏ whether two applications can communicate with‏ each other.‏

 

DICOM continues to be a very active standard‏ that continuously publishes further developments, in‏ 2021, for example, on cone-beam CT dose reports,‏ on MR prostate structured reporting, or on notation in‏ pathology. In 2022, developments followed in the area of‏ video transfer or support for PACS migrations through a‏ so-called “Archive Inventory”.‏ DICOM Working Group 23 has as its focus AI‏ applications and application hosting. One of its goals‏ is to ensure that AI applications that communicate with‏ modalities or PAC systems use correct metadata.

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HL7‏ 

HL7 (Health Level 7) version 2 has been known in‏ the healthcare sector for many years; in the hospital‏ environment, in particular, it is the standard for‏ entering patients’ medical data. A broad installation‏ of HL7 faces some limitations, especially in the‏ area of content definition, the so-called semantic‏ interoperability. HL7 has developed a version 3 for‏ this purpose, which provides for a so-called Common Document Architecture (CDA) and can thus ensure a‏ further developed semantic interoperability. However,‏ the adaptation of this standard in the market is very‏ cumbersome and limited.‏

 

HL7 has drawn the consequences from this and‏ developed a completely new approach under the name‏ FHIR (Fast Healthcare Interoperability Resources),‏ which is intended to ensure simple access, especially‏ for web-based or mobile applications. This standard has‏ been met with great interest worldwide and can already‏ be found in numerous applications.‏

 

IHE‏

IHE (Integrating the Healthcare Enterprise) is an‏ initiative that was initially started by RSNA and HIMSS‏ (Healthcare Information and Management Systems‏ Society) about 20 years ago and was intended to‏ improve the exchange of information in healthcare‏ by reducing the interoperability problems that were‏ based on different interpretations and uses of options.‏ IHE therefore coordinates established standards and‏ develops these so-called integration profiles with the aim‏ of improving communication, simplifying implementation‏ and thus ensuring more effective use of information in‏ healthcare overall.‏

 

IHE has a standardised development process whereby‏ a relevant topic is first identified, the interoperability‏ requirement is defined, and an integration profile is‏ developed. This can then be implemented and tested‏ by developers. Further down the line, adoption into‏ products is then facilitated, while governance of‏ interoperability is ensured through the publication of IHE‏ interoperability profiles.‏

 

In the meantime, there are numerous integration‏ profiles, especially in radiology, but also in other‏ medical fields, for example cardiology, ophthalmology,‏ endoscopy and others. A very essential area for IHE is‏ also the definition of integration profiles for the general‏ IT infrastructure, these are used in numerous regional or‏ national eHealth concepts.‏

 

More recent examples in radiology are REM (Radiation‏ Exposure Management), which was published about‏ ten years ago and today forms the basis of dose‏ management systems that have been in use now for‏ several years. Another interesting application is the‏ documentation of contrast medium application, whereby‏ the CM injectors can document the volumes for contrast‏ medium, saline solution as well as the pressure values in‏ corresponding templates. This information can then be‏ used across devices. The associated IHE profile CAM‏ (Contrast Administration Management) has been published‏ in 2021 as a so-called “Trial Implementation” edition.‏

 

Current integration profiles that are attracting a lot of‏ interest in radiology are two profiles in the field of AI: on‏ the one hand, the documentation and communication‏ of AI results and, on the other hand, the orchestration‏ of the workflow of AI tools. Here, it can be ensured‏ according to certain rules that for certain examinations,‏ for example a thorax CT, the relevant AI tool, in this case‏ for the detection of lung foci, is assigned the task and the‏ results are returned to the higher-level PAC system or RIS.‏

 

A very important development for IHE is the‏ implementation of so-called Connectathons. These‏ are usually five-day events for interoperability testing.‏ Often 300 or more experts from numerous companies‏ are involved who can live-test the interoperability of‏ their applications with various other partners under the‏ supervision of independent IT experts, so-called monitors.‏

 

In 2022 this Connectathon took place for the first‏ time as a joint event simultaneously in Europe and the‏ USA. A total of 89 profiles with 2,128 tests were tested,‏ 219 of these tests were transatlantic. The results of the‏ Connectathons can also be freely viewed in a browser,‏ sorted by various criteria such as company or profile.‏

 

This type of product validation is supplemented by a‏ web-based online offering from IHE, the so-called “IHE‏ SHARAZONE”. Here, data for various applications are‏ available, which allow interested developers to test their‏ own products regardless of time and place.‏

 

Internationally, IHE is organised in various regional‏ committees and subsequent national committees for‏ the further development and dissemination of IHE. The‏ actual development of the integration profiles is done in‏ domain-specific committees, for example for radiology,‏ IT infrastructure and others.‏

 

For the first time in 2015, the European Commission‏ referenced 27 IHE profiles that should be used for‏ calls for tender. These are mainly profiles in the area‏ of IT infrastructure, but also general profiles for use in‏ radiological facilities, for example.‏

 

Conflict of Interest‏

None.‏

‏Acknowledgement 

This paper has been prepared by Peter Mildenberger (Board member of IHE-Catalyst), Esther Peelen (former Chair of the IHE-Europe MarCom) and members of the IHE-Europe Extended Executive committee. Special thanks to Martina Szucsich for the review of the manuscript. [email protected]