Author: Sidney Ocanagil-Tunstall

When Region Skåne based in Lund, Sweden went digital back in spring 2019, whole slide imaging at scale was still largely untested in routine clinical environments. The scanners were available, but the operational reality of producing consistently high-quality digital slides was not yet well understood or practiced.

For laboratory manager Josefin Persson, the lesson from those early years is clear: scanning quality is not a product of scanning alone. Whole slide image (WSI) quality is a product of everything that happens before the slide reaches the scanner and during the slide’s scan.

“We had to change a lot of protocol before we even started to scan,” she explains.

The right approach

Before implementation, the lab launched a workflow optimisation project focused on standardisation. The project highlighted key changes they would have to make including controlling tissue size at the grossing stage. Larger or poorly distributed specimens that might have been acceptable for glass review created problems for scanning.

Persson describes how overfilled blocks led to incomplete or inconsistent scan coverage. Scanner constraints such as defined scan areas and slide markings meant that not all tissue on a slide could be reliably captured if preparation was not tightly controlled.

The result was a clear shift in practice:

• smaller tissue pieces
• more consistent placement in blocks
• stricter adherence to standard protocols

For Persson, this is the single most important step for any lab starting out. If grossing is not standardised, you won’t reap all the rewards going digital presents.

Small changes with big impacts

Another critical adjustment came after go-live. Region Skåne initially cut sections at four microns but quickly moved to three microns. That change was driven by scan quality.

Thicker sections created focus issues in digital images. Cells at different depths were harder to visualise clearly, leading to out-of-focus areas and an increased need for rescanning. Moving to thinner sections improved image clarity and reduced these failures.

“The result on the slides was amazing,” Persson says.

However, this improvement came with operational consequences. Cutting thinner sections is more technically demanding for histotechnologists with added difficultly in microtomy and tissue placement. This technical impact meant technicians had to adapt their technique, taking longer to process samples, and the lab had to support that transition.

Reducing rescans by fixing the root causes

A recurring theme in Persson’s account is the need to minimise rescanning. Rather than treating scan failures as a scanner problem, the team traced issues back to upstream causes:

• section thickness
• tissue distribution
• slide preparation
• artefacts on the slide

By addressing these factors, they reduced the frequency of rescans and improved overall workflow stability. This reflects a broader principle: reliable scanning depends less on post-scan correction and more on pre-scan control.

Clean slides are not optional

One of the more practical but critical lessons involved slide handling. In a traditional workflow with histopathologists responsible for the diagnosis using their microscope, minor imperfections such as fingerprints or dust never presented a problem. In a scanning workflow, artefacts such as fingerprints on glass become significant.

The scanner detects these artefacts, which can interfere with image quality or trigger scan issues. As a result, slide cleanliness became a strict requirement. Technicians had to adjust their handling practices, ensuring slides were clean before being placed in the scanner rack. This introduced an additional quality checkpoint, but one that proved essential for consistent results and higher quality slide scanning.

Standardisation across sites

Region Skåne’s implementation was further complicated by its multi-site structure. Four laboratories were involved, each with its own established ways of working.

“One of the biggest problems was that no one did the same from the beginning,” Persson notes.

For scanning to work at scale, that variation between sites had to be removed. Tissue handling, sectioning, and slide preparation all needed to be aligned across sites, but achieving that required significant effort:

• agreeing on common protocols
• training staff to follow them
• reinforcing compliance over time

Training the lab, not just installing the scanner

Persson emphasises that introducing whole slide imaging is as much about training as it is about technology. Technicians needed to understand:

• why thinner sections matter
• how tissue placement affects scan coverage
• how handling impacts artefacts
• what the final digital image looks like

This feedback loop, educating staff on how preparation choices affect the scanned result helped build awareness and improve quality over time. Importantly, the lab treated scanning as a shared responsibility. It was not confined to a single step or role but distributed across the workflow.

Getting the setup right from the start

While much of the learning came from experience, Persson does not believe the team would fundamentally change their approach. The implementation was iterative but grounded in a clear direction: improve the laboratory workflow to support scanning, rather than forcing scanning into an unchanged process.

For labs starting out, her advice is direct:

• standardise early
• control tissue size and placement
• review section thickness
• enforce slide cleanliness
• align practices across sites
• listen to the technicians doing the work

Technology still matters, reliable scanners and responsive vendors are important, but they are not the be all and end all.

A workflow, not a machine

Region Skåne’s experience reframes how whole slide imaging should be approached. Scanning is often discussed in terms of hardware and throughput. Josefin Persson’s perspective is different. As a lab manager that has been through the process of digitisation at scale, putting that experience into practice for some time, it was clear that upstream methodologies have large impacts on the quality and consistency of whole slide images.

Several years on from their first digital sign out, the lab has refined its process to the point where high-quality scanning is routine. For labs approaching whole slide imaging for the first time, that may be the most useful takeaway. Getting scanning right isn’t just about the scanner itself, it requires a wider review of how you get to scanning in the first place.