Radiology is the medical specialty that uses imaging, such as X-ray, CT, MRI, ultrasound, mammography and nuclear medicine, to diagnose disease and guide treatment. Every study a radiology department performs passes through a chain of software, from the order in the EHR to the signed report back in the chart.
This guide follows that chain. It covers what each system owns, how a study moves through them, the standards that carry each handoff, how findings reach clinicians and patients, where department workflows break, and how to decide which system to replace first.
What software runs a radiology department?
Building or replacing radiology software?
Agnotic builds radiology workflow software, from order and scheduling tools to RIS and PACS integrations, reporting and result delivery.
A radiology department runs on four connected systems: order entry in the EHR, a radiology information system (RIS) for scheduling and exam tracking, a picture archiving and communication system (PACS) for storing and viewing images, and a reporting system where radiologists dictate and sign. Interfaces between them carry each study from order to result.
Around those four sit supporting tools: a DICOM router that sends images to the right destination, AI applications that analyze studies, a patient portal or image-sharing service, and the billing system that codes each exam.
The vendors differ from site to site. Some hospitals run the RIS inside the EHR, some imaging centers buy a combined RIS and PACS, and teleradiology groups often bring their own reporting system. The handoffs between systems stay the same.
How does a study move from order to signed report?
A radiology study moves through six handoffs, and each one is a message or an image transfer between two systems. Naming them is the first step in any radiology software project.
- 1. Order: The clinician orders the exam in the EHR. An HL7 v2 order message reaches the RIS with the patient, exam code, priority and reason for the exam.
- 2. Schedule and protocol: The RIS books the room and time, and a radiologist or technologist sets the protocol, such as contrast or no contrast.
- 3. Worklist: The scanner queries the DICOM Modality Worklist, so patient and exam details arrive on the modality without retyping.
- 4. Acquire and store: The modality sends DICOM images to PACS, often through a router that also copies them to AI tools or an archive, and reports that the procedure is complete.
- 5. Read and report: The radiologist opens the study from a reading worklist, dictates into the reporting system and signs. Critical results trigger a documented call to the ordering clinician.
- 6. Result and bill: The signed report returns to the EHR as an HL7 v2 result message, a viewer link goes with it, and the exam is coded for billing.
One identifier ties all six steps together: the accession number. If the EHR, RIS, PACS and reporting system each assign their own, reports attach to the wrong study and charges fall out of sync.
RIS, PACS and reporting: who owns what
A common source of radiology integration problems is two systems that both believe they own the same data. Settle ownership for each item before building interfaces.
- EHR: Owns the order, the patient's identity and demographics, and the final place where the report is read by the care team.
- RIS: Owns scheduling, exam status, protocols, technologist notes, the accession number and often the charge record.
- PACS: Owns the images, the hanging protocols that lay them out for reading, prior studies and image sharing.
- Reporting system: Owns report templates, dictation, signing, addenda and the structured findings within the report.
- Worklist or orchestration layer: In multi-site groups, owns which radiologist reads which study, across several RIS and PACS.
Corrections are where ownership matters most. When a patient is merged in the EHR or an exam is changed after scanning, the change has to flow to every downstream system in the right order, or images and reports end up under the wrong record.
Handling corrections without losing studies
- Patient merge: The EHR sends the merge, the RIS updates its record, and PACS moves the images from the old identifier to the surviving one. Each step is logged.
- Exam change after scanning: When a CT abdomen becomes a CT abdomen and pelvis, the RIS updates the order and charge, and PACS updates the study description so hanging protocols still work.
- Wrong patient scanned: The study is moved to the correct patient in PACS, the report is cancelled or reissued, and the EHR receives a corrected result with an audit trail.
- Report addendum: The reporting system sends the addendum as a corrected result, and the EHR shows the clinician that the report has changed.
Write each of these cases into the interface specification and test them before go-live. They are rare on any one day but certain over a year.
Which standards hold the workflow together?
Two standards carry nearly every radiology handoff: HL7 v2 for orders, status and results, and DICOM for images and worklists. IHE profiles describe how to combine them.
- DICOM: The international standard for medical images and related information, published by NEMA. It defines image storage, query and retrieve, Modality Worklist and the procedure step messages a scanner sends.
- IHE Scheduled Workflow.b: The IHE Radiology profile that coordinates ordering, scheduling, acquisition, storage and viewing across the EHR, RIS, PACS and modalities. It requires HL7 v2.5 and uses Modality Worklist, Modality Performed Procedure Step and Storage Commitment.
- HL7 v2 messages: Order messages carry the request into the RIS, and result messages carry the signed report back to the EHR.
In requests for proposals, ask vendors which IHE actors they implement, not only whether they support HL7 and DICOM. Two systems can both support DICOM and still fail to exchange a worklist or a storage commitment.
FHIR is appearing at the edges, for image-sharing links, patient access and some reporting tools, but the core department workflow still runs on HL7 v2 and DICOM.
How do results reach clinicians and patients?
Results reach the ordering clinician through the EHR result interface, and urgent findings need a direct, documented call on top of that. Patients see reports through the portal, and mammography reports carry extra federal rules.
- Critical results: The reporting system flags the finding, records who was called and when, and escalates if nobody acknowledges it.
- Incidental findings: Recommendations such as a follow-up CT in six months become a task with an owner and a due date, not only a sentence in the report.
- Mammography: FDA's amendments to the Mammography Quality Standards Act regulations took effect on 10 September 2024. They require facilities to report breast density in the radiologist's report and in the lay summary sent to the patient.
- Patient portal release: Reports flow to the portal under the organization's release rules, and the portal links to the images where a sharing service exists.
Follow-up tracking is software work, even where it is run today from a spreadsheet. A small service that reads structured recommendations from reports and tracks each one to a completed exam or a documented decision closes a known safety gap.
For mammography, template the density statement in the reporting system and generate the lay letter from the same field, so the two can never disagree.
Where radiology workflows break
Radiology workflows break at handoffs, codes and corrections. Watch for these failure points.
- Exam code drift: The EHR, RIS and billing system use different code lists, so orders map to the wrong protocol or charge.
- Duplicate accession numbers: Two systems assign numbers, and reports attach to the wrong study.
- Missed merges: A patient merge in the EHR never reaches PACS, so prior studies are hidden at reading time.
- Manual worklist entry: Technologists type patient details at the scanner when the worklist fails, and typos create orphan studies.
- AI on a separate screen: AI results open in a window the radiologist does not use, so findings never reach the report.
- Untracked follow-ups: Incidental findings recommended for follow-up have no owner and are never scheduled.
Test interfaces with real exam codes, real merge cases and real downtime recovery before go-live. Sample messages from a vendor often leave out the edge cases that break production.
Downtime needs its own plan. When the RIS or EHR interface is down, technologists scan from paper requisitions, and every study acquired in that window has to be reconciled to an order and accession number once systems return.
Should you replace the RIS, the PACS or neither?
Replace the system that blocks the workflow, not the oldest one. Often the better first project is a new interface, worklist or reporting layer on top of systems you keep.
- Replace the PACS: When storage, viewing speed or prior-study retrieval limits reading, and the archive can be migrated in stages.
- Replace the RIS: When scheduling, protocoling or charge capture runs outside the system on paper or spreadsheets.
- Add a reporting layer: When templates, structured findings or follow-up tracking are the gap, and RIS and PACS work well.
- Add an orchestration worklist: When radiologists read across several sites or systems and assignment is manual.
- Keep both and fix interfaces: When the core systems are sound but codes, merges or accession numbers are not aligned.
Image migration can set the length of a PACS change. Plan it early, with the archive's export limits and study counts measured, not estimated.
How Agnotic can help
Radiology software projects succeed or fail on the handoffs between systems. Agnotic Technologies builds those handoffs for practices, imaging centers and health tech teams: order and scheduling tools, HL7 v2 and DICOM interfaces between the EHR, RIS and PACS, reporting templates and follow-up tracking.
Your radiologists set the protocols, templates and reporting rules. Agnotic builds the software that carries them, tests it against your real exam codes and merge cases, and supports the cutover.
Plan radiology software with Agnotic
Explore radiology software development, or browse more articles in the Imaging hub.
Related reading on Agnotic
Continue with AI medical imaging, imaging informatics, HL7 orders and results, radiology cybersecurity and the medical imaging and PACS solution.
