Delivering an accurate diagnosis to your patients is your priority. The human and financial cost of misdiagnosis is devastating for families and healthcare providers. Nearly 29 percent of paid malpractice claims are attributed to diagnostic errors.
Healthcare providers that are looking to improve diagnostic accuracy and reduce the risks of misdiagnosis should develop best practices for preparing and scanning slides for telepathology, also known as digital pathology.
In this article, we’ll discuss 5 best practices for manipulating scanning slides for the best imaging.
What Is Digital Pathology?
Digital pathology is simply the practice of pathology at a distance. The pathologist is not in the lab examining the actual specimen but is viewing an image of the slide. Depending on the system, the image can be live or static.
What Are the 3 Systems of Digital Pathology for Scanning Slides?
The 3 digital pathology systems for scanning slides are imaged-based, real-time, and virtual slides. All of these can support diagnostic pathology from remote locations. Let’s take a look at how each of these systems works.
Telepathology, in its simplest form, is image-based. A digital image of the slide is created and shared on a network or via email. The image-based system is the least expensive but also has limited points of view which can prevent an accurate diagnosis. With this system, the pathologist is limited to a static, often low-resolution, image.
Real-time, or robotic, telepathology is a system where a pathologist uses software to control a motorized microscope to change focus, illumination, magnification, and field of view.
The pathologist can also ask the lab tech to adjust the slide under the microscope. The live image is high resolution. This system has a nearly 100 percent diagnostic accuracy. A potential disadvantage is Internet signal latency if Internet traffic is high.
Virtual slide systems are the most recent advancement in telepathology. These systems scan and digitize high-resolution images that are stored on computer servers. The pathologist can examine the slides at various magnifications. Virtual slide scanners can scan a high volume of slides, making one or more virtual slides per minute.
No matter what system you use, excellent slide preparation for telepathology is essential.
Preparing High-Quality Specimens and Slides for Digital Pathology
Accurate diagnosis through digital pathology relies on carefully prepared samples. It’s important that the sample is sized, stained, and mounted properly.
A digitized image of a slide is static (except in real-time digital pathology), so the pathologist interpreting the slide can’t manipulate it for a better view. The correct interpretation depends on capturing an accurate, high-quality image.
Learn how to scan slides with a digital pathology scanner with these 5 tips.
Tip One: Sizing
The size of the sample should be no more than 3 to 4 micrometers. While this is standard, it’s important to note that digital pathology scanners have a smaller depth of field. This means a shorter distance between the closest object plane in focus to the farthest plane in focus.
Thick specimen samples should be z-stacked to avoid out-of-focus scans. Uneven specimens should be cut or manipulated until they’re flat.
Tip Two: Staining
Staining is meant to provide good color contrast. If too much stain is used, the background will get stained, preventing contrast. If too little is used, the sample will be too faint for the scanner to properly digitize.
Tip Three: Mounting
It’s critical that specimens don’t have folds, wrinkles, or air bubbles. If the specimen is not mounted flat this will prevent optimal focus.
For example, if a specimen has a fold, the digital scanner might focus on the height of the fold. This would leave other cell clusters out of focus. If the out of focus cells contain cancer but they’re not clear in the digitized image, the interpretation by the pathologist won’t be accurate.
Mounting even the best specimens using the wrong coverslip can be problematic. It’s important to consult with the equipment provider about which coverslip to use.
While some digital pathology scanners recommend glass slides, these can have a glue that will jam the scanner. Plastic coverslips can be problematic as well since they may warp over time. equipment. Coverslips that are too small for the slide may cause the scanner to read their edges as part of the specimen.
Tip Four: Inspecting
A slide should be perfectly clean before being put through a digital pathology scanner. While using a clean slide is always a best practice, it’s helpful to understand why this is especially critical for digital pathology.
You need to inspect your slide anything that may interfere with inaccurate image capture and that may damage the scanning equipment. Use this checklist:
- Labels should be placed on the top of the slide and should not hang over sides
- Remove any dust, debris, water spots, or fingerprints from the slide and coverslip
- Do not use slides with cracks or chips
- Make sure the slide is completely dry
The last piece of the inspection step is to do a test run by holding the slide up to the light and viewing it under a regular microscope. If everything looks correct, it’s time to scan!
Tip Five: Scanning
Digital pathology scanners are meant to automatically detect all tissue on a slide and exclude irrelevant objects like labels and pen marks. Sub-optimal staining and mounting will lead to poor specimen detection by the scanner.
If you have a slide that has sub-optimal staining and mounting, the scanner may focus on the wrong scanning plane. If this happens, the specimen will be out of focus. If preparing a new slide is not an option, try to place focus points away from the defects.
Digital pathology scanners have automatic focusing. Focus points are automatically detected and should be distributed evenly across the specimen. If parts of the slide are not in focus when scanning, you can manually add focus points.
Review your scanned slide through the scanner’s image viewer. First, review at low magnification of 4x to check for out-of-focus areas.
Next, set the magnification at which the high-resolution image was captured. You will need to perform a field-by-field review horizontally, then vertically. Check for out-of-focus areas.