PathQA Sierra DICOMiser
Any Scanner, Any IMS, Interoperable & Standardised Colour
A new QA solution from PathQA addresses two challenges in digital pathology: variation in digital colour across scanner vendors and the need for a simple, standards-based solution compatible with pre-existing workflows.
Digitisation Presents Colour Quality Challenges in Digitalisation
Digital colour variation and proprietary image formats in WSI are technical inconsistencies between pathology scanners. Tissue stain and thickness colour differences are expected lab-based variability caused by sample preparation, whereas scanner digital colour variations are unintended side-effects rooted in inadequate or lack of colour management by scanners.
Humans can differentiate these sources of variation, so when a glass tissue slide is imaged by different scanners that produce different coloured outputs, human intuition knows at least some images, if not all, must simply be incorrect. This quality assurance and regulatory issue needs measurement and management to standards as digital pathology adoption grows.
AI is also sensitive to colour variation as domain shift, a contributing factor for AI development resorting to huge, costly foundation models and relying on statistical probabilities via black-box normalisation in attempts to cure the problem. Routinely standardising digital colour before AI, especially as scanners can drift in colour response, is a quicker, effective, explainable, trustworthy and preventative method that removes variation upfront – an ounce of prevention is worth a pound of cure.
An international AI study with PathQA collaborators from multiple institutes across Sweden, Norway, Denmark and Finland (Physical Color Calibration of Digital Pathology Scanners for Robust Artificial Intelligence–Assisted Cancer Diagnosis - Modern Pathology) used physical colour calibration to the ground truth of histopathology via Sierra Slides and scanner-agnostic ICC colour profiles to standardise multi-vendor scanner colour. This improved AI robustness and reliability, even from smaller datasets and beyond foundation models, whilst increasing pathologist concordance.
A practical challenge is introducing a simple and universal solution for users with a plethora of vendors, each with their own objectives and capabilities, that can insert routinely into highly interoperable workflows. Enter DICOM, a global and non-proprietary standard for defining an image format, including ICC metadata, and is interoperable across the end-to-end workflow.
Combining standardised colour with standardised format by embedding Sierra ICC profiles into DICOM (DICOM-ICC) enables PathQA to offer a universal QA function that can bridge the gap between variable scanner output and the benefits of uniform IMS and AI input. PathQA’s Sierra DICOM-ICC makes any scanner to be like every scanner with consistent colour in any IMS.
The PathQA DICOM-ICC Solution and Impact
Digital pathology scanner vendors make automated imaging devices that are good at satisfying workflow, throughput, mechanical efficiency and infrastructure needs. Many scanners have excellent focus, resolution, magnification and increasingly interoperability via DICOM. In many respects, customers are spoiled for choice from a large number of vendors.
Some scanners also use generic colour profiles to modify their colour output in proprietary viewers. However, these colour profiles generalise images rather than standardise individual machine variability to the ground truth as Sierra does. Proprietary image formats can restrict viewers presenting colour as intended, therefore also changing quality presented to the same users in different software. Whilst some scanner vendors address the problem of colour fidelity, to varying accuracy, they use their own methods and therefore true standardisation by scanners alone is elusive.
Independent and interoperable colour QA compliments digital pathology scanner and software products by providing a route to universally and reliably removing digital colour variation. Scanners can market based upon what they are very good at: resolution; speed; size; capacity; throughput; cost. PathQA’s Sierra can take care of absolute colour standardisation on their behalf, and intertwining with DICOM means IMS and AI workflows always expect standardised images. PathQA’s DICOM-ICC has been validated in the 2025 WG26 DICOM Connectathon, the Sierra slide aligns with FDA guidance for colour calibration targets, and high-fidelity Sierra ICC profiles meet the International Color Consortium v4.0 standard and are less than 230KB.
Available as a free, RUO upgrade to PathQA VS-Profiler colour QA software, the Sierra DICOMiser sits between any upstream scanner that has scanned a valid Sierra calibration slide and any downstream IMS for viewing WSIs. After rapid, cloud-based generation of QA reports and ICC profiles from Sierra images, a button in the in-built viewer lets users convert individual WSIs from proprietary formats and variable colour to interoperable DICOM with standardised, validated colour for IMS viewing with no software vendor changes needed.
“This world-first, independent and interoperable solution is a big step towards real industry-wide image standardisation and offers a leap in quality and consistency accessible by all digital pathology users” commented Dr Rick Salmon, CEO at PathQA. “With Sierra software and algorithms there is no need for users to be digital colour experts, IMS and viewing platforms that meet DICOM compliance don’t need to make engineering changes and the function is available to all Sierra customers. Organisations get ROI on their current scanner portfolio, whilst removing vendor-lock in when choosing their next scanners or IMS”. Dr Salmon continued “QA improvements are easily adopted by interconnected clinical and healthcare networks, increasing diagnostic and prognostic confidence for patient quality of care. GLP and routine quality monitoring for multi-site preclinical research in pharma and CRO benefits safer and more efficient drug development. AI developers can ensure input consistency for algorithm reliability, needing less training data whilst accounting for scanner aging, for AI that is more explainable, regulatable and can integrate into and benefit from standardised workflows”
Sierra DICOM-ICC compatibility with IMS vendors - Integration into workflow and moving towards industry standardisation.
The following IMS and viewer platforms have already demonstrated compatibility with reading PathQA’s Sierra DICOM-ICC format for displaying standardized colour:
Vendors: Aiforia Clinical, Aurora mScope, Gestalt PathFlow, Gpi4Med.PATHOLOGY, Ibex, Indica Labs HALO/HALO Link, Lumea Viewer +, PathAI AISight, Pathomation PMA, Pathpresenter, Proscia Concentriq, Sectra, TechCyte Fusion® Tribun Health CaloPix®, Visiopharm and several open-source viewers.
This list will be updated as more IMS vendors become DICOM-ICC-compatible. If a vendor or open-source viewer for interested end-users is not listed, or if a vendor wishes to be listed, please contact enquiries@pathqa.co.uk and PathQA can provide test images to confirm functionality.
Key Benefits of DICOM-ICC in Clinical QA and Preclinical/CRO GLP
Reportable metrics track scanner colour variation over type and time
Quantifiable and visible correction to international standards
Global interoperability within a quality-assured, regulatable workflow
User-enabled, scanner-agnostic standardization and fidelity of all digitized tissue
Makes the scanners you already have be the quality you want
Buy the scanners you want and make the quality you need
Keep using the same IMS platforms you are familiar with and dependent on
Key Benefits of DICOM-ICC in AI and workflow
Consistent input means consistent output for AI reliability
Mitigate scanner aging and new scanner variations via routine QA and recalibration.
Remove colour variation for less black-box normalization, increasing explainability.
Prevention is better than cure - less time solving variability, more effort on diagnosis
Fewer high-quality images for better accuracy to low-quality big-data with big-storage.
Reduce or remove site-specific and additional scanner retraining – scalable to multi-site projects whilst also increasing AI accessibility for smaller organisations
Peer-reviewed ICC improvements demonstrated, even with foundation models.
Regulatable - Aligns with FDA guidelines for WSI precision and accuracy, facilitates inter-lab quality assurance and data sharing to address regulatory concerns.
More background, use-cases, publications and ordering information for the Sierra portfolio of products can be found at www.pathqa.co.uk or by contacting enquiries@pathqa.co.uk.