In today’s digitally connected world, healthcare organisations rely on complex networks of systems to manage patient records, diagnostics, imaging, and clinical workflows. But behind the scenes, ensuring that all these systems can talk to each other requires a common language – or, more accurately, common standards.
In this article, we’ll break some of the most important healthcare information interchange standards including DICOM, HL7, and IHE. Whether you’re integrating hospital systems or planning a digital transformation strategy, these standards are foundational to success.
DICOM – The gold standard for medical imaging
DICOM, short for Digital Imaging and Communications in Medicine, is the global standard for storing, transmitting, and managing medical imaging data. From CT scans and MRIs to ultrasound and X-rays, DICOM ensures that imaging devices from different manufacturers can work together — and that radiology images can be accurately exchanged and viewed across systems.
What sets DICOM apart is its comprehensiveness. It covers everything from file formatting and image compression to metadata structures and communication protocols. In fact, DICOM even includes its own network communication protocol (based on TCP/IP) to support seamless interoperability between modalities, archives, and viewing software.
Explore more: dicom.nema.org
HL7 – The backbone of administrative and clinical data
Health Level Seven (HL7) is a family of standards focused on the exchange of clinical and administrative data between healthcare systems. HL7 comes in different versions, with the most widely adopted being HL7 Version 2 (V2).
V2 messages are text-based and use delimiters (like | and ^) to separate fields — making them relatively easy to read and implement. This version powers many day-to-day hospital communications, including admissions, discharge, transfers (ADT), lab results, and billing information.
HL7 Version 3 (V3) introduced a more structured, XML-based format with a formal reference model, but its complexity has hindered widespread adoption. However, one significant outcome of V3 is the Clinical Document Architecture (CDA) — a format used to share structured patient summaries, discharge reports, and other documents within and between organisations.
Learn more: www.hl7.org
IHE – Connecting standards to real-world use cases
Unlike DICOM or HL7, Integrating the Healthcare Enterprise (IHE) is not a standard in itself, but an initiative that bridges the gap between standards and implementation. IHE develops profiles — detailed implementation guides that specify how existing standards (like HL7 or DICOM) should be used in real-world clinical scenarios.
IHE profiles are developed by clinicians, IT experts, and vendors working together to solve specific interoperability challenges. One of the most influential profiles is XDS (Cross-Enterprise Document Sharing) — a framework for sharing patient documents across healthcare organisations. XDS enables a federated approach to health information exchange, where documents remain in local systems but are discoverable and retrievable across the network.
IHE also hosts annual Connectathon events — large-scale testing sessions where vendors validate the interoperability of their solutions against IHE profiles.
Get involved: www.ihe.net
Why these standards matter
Whether you’re integrating electronic health records (EHRs), launching a new diagnostic service, or enabling cross-site access to imaging, adopting standards like DICOM, HL7, and IHE is essential. They:
- Enable interoperability between disparate systems and devices.
- Support patient safety by reducing manual data entry and miscommunication.
- Improve operational efficiency, especially in multi-vendor environments.
- Lay the groundwork for scalable digital transformation.
In the UK, many NHS and private healthcare organisations are at different stages of digital maturity. Understanding these standards — and how to apply them — is a critical step in delivering patient-centred, connected care.
While DICOM, HL7, and IHE are some of the most well-established and widely used standards in healthcare integration, there are several other important standards and frameworks worth knowing about, especially as digital health evolves.
FHIR (Fast Healthcare Interoperability Resources)
Perhaps the most exciting recent development in healthcare standards, FHIR (pronounced “fire”) is developed by HL7 and aims to simplify the exchange of healthcare data using modern web technologies like RESTful APIs, JSON, and XML.
FHIR is designed to be developer-friendly, modular, and adaptable — making it a popular choice for digital health apps, mobile tools, and integrated platforms. It’s also being used in NHS England’s Interoperability strategy, and forms the basis of GP Connect, NHS Login, and National Record Locator Services.
Learn more: https://www.hl7.org/fhir
openEHR
openEHR is both a specification and an open platform architecture for lifelong electronic health records. It separates clinical knowledge (data models and rules) from the software implementation, allowing clinicians to shape how data is structured via a system of archetypes and templates.
openEHR is used in several NHS trusts and international health systems (notably in Norway and parts of Germany), especially where long-term record integrity, data reuse, and semantic interoperability are important.
More info: https://www.openehr.org/
SNOMED CT
SNOMED CT (Systematized Nomenclature of Medicine – Clinical Terms) is not a messaging or data exchange standard, but a clinical terminology system. It provides a common language for consistently coding clinical content in EHRs — from diagnoses and symptoms to procedures and observations.
SNOMED CT is widely used across the NHS and is essential for semantic interoperability, enabling better decision support, analytics, and reporting.
More info: https://www.snomed.org/
LOINC (Logical Observation Identifiers Names and Codes)
LOINC is another important terminology standard — this time focused specifically on laboratory and clinical observations (e.g., blood tests, vital signs). It’s commonly used alongside HL7 or FHIR to encode the meaning of test results, ensuring consistent interpretation across systems.
More info: https://loinc.org/
ISO/IEEE 11073
This family of standards focuses on interfacing with medical devices — particularly for personal health devices like blood pressure monitors, glucose meters, and pulse oximeters. It’s especially relevant in remote patient monitoring, IoT health, and telehealth environments.
More info: https://standards.ieee.org/11073/
Summary
| Standard/Framework | Focus Area | Usage |
| DICOM | Imaging | Radiology, pathology, ophthalmology |
| HL7 V2/V3 | Messaging | ADT, labs, billing, basic clinical data |
| FHIR | APIs | Apps, portals, integrations, NHS interoperability |
| IHE | Profiles | Connectathons, real-world standardised use cases |
| openEHR | EHR modelling | Longitudinal patient records |
| SNOMED CT | Terminology | Clinical coding |
| LOINC | Terminology | Lab results, vital signs |
| ISO/IEEE 11073 | Device data | Wearables, remote health devices |