Medical Imaging: DICOM, HL7, IHE and XDS Standards
We explore the various standards for transmitting medical information in text format as well as for sharing clinical images, and the models that seek to unify this information globally.
For a health facility to efficiently run medical image management and storage systems, studies must comply with international standards that guarantee their reproduction and communication.
Some of these are DICOM and HL7, Digital Imaging and Communications in Medicine and Health Level 7 respectively, which the best PACS systems on the market work with.1
These standards emerged from the need to share patients' clinical images among different specialists located remotely, at other institutions, or with patients themselves digitally. For this reason, it is essential for health services to adapt to international digital medical standards for text and images.
Below, we will look at the most frequently used standards.
DICOM Standard
The DICOM standard is directly related to the transmission of medical images. It is a universal format that does not depend on imaging equipment vendors or manufacturers, which has increased productivity.2
DICOM merges a data format with communication protocols, from the diagnostic modality's scanner to the various devices on the network.1 It consists of seven layers that carry medical images to storage servers or physicians' computers.2
This format feeds PACS systems so that these studies can ultimately be managed and safeguarded for the period established by law.1,2
In short, although the DICOM standard provides a fairly comprehensive record of patients' medical images, it is basically oriented toward viewing them and providing characteristic data for their interpretation. For example, the size of the images, the bytes consumed by each part of the study, and good resolution to ensure a quality diagnosis.2
HL7 Standard
For its part, the HL7 standard is the format for text data that can be embedded in medical images. Similarly, this offers the advantage of being able to communicate these studies with more detailed healthcare information.2,3 Its most common use is the electronic intrahospital transmission related to the delivery of various healthcare services.1
As its name indicates, HL7, or Health Level 7, is the highest level for open communication systems, complying with ISO regulations. In other words, it has seven levels for connecting healthcare information electronically, regardless of vendor. This means messages can be shared in this format with a certain degree of compression, regardless of operating system.2
There are several versions of HL7, and the choice depends on the service required at the health facility. HL7 2.0 messaging allows electronic sending and receiving of health data, while version 3.0, the most widely used, bases its information on the RIM (Reference Information Model) to create messages. SPL HL7 also stands out, used for medication identification.2
Do the DICOM and HL7 Standards Work Together?
Indeed, the DICOM and HL7 standards work together. This is most advisable for any health facility, since they complement each other to provide physicians and patients with clinical images and the associated healthcare information.3
For that reason, both standards are used in most hospitals, to serve Radiology Information Systems (RIS) and Hospital Information Systems (HIS), which make it possible to maintain patients' history and records within a health facility.1
IHE and XDS Standards
The idea behind generating standards like DICOM and HL7 is that they be used in health facilities to drive globalization in the communication and transmission of clinical data and studies. The goal of achieving this alignment has given rise to a model known as Integrating the Healthcare Enterprise (IHE).
Thanks to the IHE model, many manufacturers of imaging and medical equipment came to understand the importance of working with standards like DICOM and HL7, referred to as the data model, to speed up integration profiles.2 PACS systems are an example of this, since most of them work with DICOM to manage and store patients' medical images.
The IHE model has ten profiles, among which we highlight information reconciliation and access to patients' medical images. Its purpose is to guide providers in querying and retrieving clinical images for fast, secure exchange.2 For this to be possible, it is essential that health facilities register according to their country in the Interoperability Guide.5
Once registered, a health facility can make use of XDS (Cross-Enterprise Document Sharing) networks to share medical images and other relevant information among professionals. The XDS infrastructure is considered the IHE standard for viewing, sharing and retrieving these clinical studies, using the metadata of the documents in question for this purpose.5
In turn, the XDS infrastructure operates with the DICOM and HL7 standards and, through local configurations, has been approved by the IHE model for the retrieval and exchange of medical images from different modalities.5 This further reinforces the importance of ensuring that the PACS you use meets international text and image standards.
Eva PACS Standards
Eva PACS is a solution to the problem faced by health facilities of all kinds that want optimal management and storage of images from different modalities. Eva's PACS system meets the standards mentioned above. The system will also let you upload and download files in different formats for sharing, such as DICOM, JPG and PDF.
Having a system like Eva PACS makes it possible to exchange these images among hospitals, physicians and patients alike.
Request a Demo of Eden PACS.
References
1 Centro Nacional de Excelencia Tecnológica en Salud (National Center for Technological Excellence in Health) (2009). Sistemas para archivo y comunicación de imágenes. Mexico, Secretaría de Salud (Ministry of Health).
2 Huang, H. K. (2004). Pacs And Imaging Informatics Basic Principles And Applications. University of California, Los Angeles, p. 691.
3 DICOM. DICOMweb and other standards. https://www.dicomstandard.org/
4 Integrating the Healthcare Enterprise. Making Healthcare Interoperable. https://www.ihe.net/5 Nictiz. XDS cross-enterprise document sharing. https://www.nictiz.nl/standaarden/xds/