5.3 Radiology Workflow, RIS/HIS Integration, Teleradiology & Informatics Quality Assurance

5.3 Radiology Workflow, RIS/HIS Integration, Teleradiology & Informatics Quality Assurance

Imaging Science Informatics carries 13 items in the Radiation Physics subject, and four of its seven sub-topics are about workflow, distribution, telemedicine and informatics quality assurance rather than about PACS hardware. Those competencies read: explain how technology in computer and information science are processed to operationalize and implement workflow in radiology; apply technology in computer and information systems in the distribution and networking of radiological systems; apply practical and clinical imaging techniques to telemedicine and teleradiology; recognize current research and development of technologies in radiological modalities; and apply quality assurance principles in computer and information science and web application-based telemedicine and teleradiology.

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1. The Four Systems and What Each Owns

How they talk. Two standards do all the work:

• HL7 (Health Level 7) carries text: patient demographics, orders, admission-discharge-transfer messages, and reports. HL7 flows HIS to RIS and RIS to HIS.
• DICOM (Digital Imaging and Communications in Medicine) carries images and image-related services: storage, query/retrieve, print, and the modality worklist. DICOM flows RIS to modality and modality to PACS.

A useful mnemonic: HL7 moves words, DICOM moves pictures.

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2. The End-to-End Workflow

1. Order entry. The clinician places an order in the HIS or through computerised physician order entry. An HL7 order message travels to the RIS.
2. Scheduling and accession. The RIS schedules the examination and generates a unique accession number that will follow the study everywhere.
3. DICOM Modality Worklist (MWL). The modality queries the worklist server and downloads the patient name, patient ID, accession number, study description and procedure code directly into the machine. The technologist selects the patient from the list rather than typing.
4. Acquisition. Images are created, tagged with the worklist demographics, and reconstructed.
5. Technologist quality control. The technologist reviews the images for positioning, collimation, markers, exposure indicator and artifacts, then verifies the study.
6. DICOM Store. Verified images are sent to the PACS archive; the PACS returns a storage commitment.
7. Interpretation. The radiologist reads on a calibrated diagnostic workstation with prior comparison studies auto-loaded by the PACS "relevant priors" rules.
8. Reporting. The report is dictated, often through speech recognition, signed in the RIS, and pushed back to the HIS as an HL7 result message.
9. Distribution. The report and images become visible in the electronic medical record, on the referring physician portal, and to the patient.

Why the modality worklist matters more than any other single control. Manual typing at the modality console creates mismatched demographics, duplicate patient records, studies that never match an order, and — worst — wrong-patient studies. Nearly every "image cannot be found in PACS" incident traces back to a manually keyed study whose patient ID does not match the order. The technologist's rule is simple: always pull the patient from the worklist; never type.

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3. Storage Tiering and Retention

Design considerations you should be able to discuss: redundancy (RAID arrays, mirrored archives, off-site disaster recovery), retention period (set by institutional policy and national regulation — retain longer for paediatric and mammography studies), prefetching (the PACS moves likely-needed priors to online storage the night before a scheduled examination), and compression.

Compression is examinable. Lossless compression (typically 2:1 to 3:1) is fully reversible and always acceptable. Lossy compression achieves far higher ratios but discards data irreversibly; it may only be used where a validated, modality-specific and body-part-specific ratio has been shown not to degrade diagnostic accuracy, and its use must be documented. Mammography is the most restrictive application.

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4. Teleradiology and Telemedicine

Teleradiology is the electronic transmission of radiological images from one location to another for the purposes of interpretation or consultation. In the Philippine setting it is what allows a district or municipal hospital without a resident radiologist to obtain a report from a subspecialist in a regional centre — a genuine access-to-care technology, not merely a convenience.

Requirements for a defensible teleradiology service:

Telemedicine is the broader term — remote clinical care of any kind. Teleradiology is one of its oldest and most mature branches, because radiological images were digital before most other clinical data.

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5. Informatics Quality Assurance

The Board asks you to apply quality assurance principles in computer and information science. In practice that means a defined, scheduled, documented programme covering:

• Display quality control. Monthly (or more frequent) checks of diagnostic and technologist review monitors using a standard test pattern such as the SMPTE or TG18-QC pattern: verify the 0-5% and 95-100% contrast patches are distinguishable, check grayscale linearity against the DICOM Grayscale Standard Display Function, measure maximum luminance and ambient light. Diagnostic monitors are typically 3-5 megapixel and mammography monitors 5-10 megapixel.
• Workflow metrics. Order-to-exam time, exam-to-report turnaround, and the size and age of the unverified queue. A growing unverified queue means studies acquired but never sent — a patient-safety issue, not an IT issue.
• Exception queue management. Studies that arrive at PACS without a matching order sit in an exception or "broken" queue and must be reconciled promptly by an authorised user; unreconciled studies are effectively lost.
• Repeat/reject analysis. The digital equivalent of film reject analysis; the PACS or modality logs deleted and repeated images, and the departmental target is typically well under 10%, analysed by cause and by body part.
• Data integrity. Regular verification of archive integrity, restore testing from backup, and documented disaster recovery drills. An archive that has never been test-restored is an untested archive.
• Confidentiality. Automatic screen locking, no shared logins, no image capture on personal devices, and no transmission of patient images through consumer messaging applications — a real and frequent breach pathway in busy departments.
• Downtime procedures. Written, rehearsed procedures for PACS or RIS outage: how to acquire, how to label, how to store locally, and how to reconcile after recovery.

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6. Current Developments the Board Expects You to Recognise

The TOS asks the examinee to recognize current research and development of technologies in radiological modalities. Be able to name and describe, at a conceptual level:

• Artificial intelligence and computer-aided detection for triage, worklist prioritisation of critical findings, and quantification; note that these are decision-support tools and do not transfer diagnostic responsibility away from the radiologist.
• Deep-learning image reconstruction in CT and MRI, which permits dose or scan-time reduction at preserved image quality.
• Photon-counting detector CT, offering improved spectral information and dose efficiency compared with conventional energy-integrating detectors.
• Dose-tracking and dose-index registries, which aggregate CTDIvol, dose-length product and dose-area product across a department to benchmark against diagnostic reference levels.
• Vendor-neutral archives and cloud PACS, decoupling long-term storage from any single vendor's proprietary format.
• Structured reporting, which turns the narrative report into discrete, queryable data elements.