Quantitative Digital Pathology with Image-Pro Premier Software
The advent of affordable, high-resolution digital capture
techniques is good news for the research pathology communities. Costs to
collect, display and analyze large format images have dramatically shrunk in
recent years. The ability to evaluate data in entire tissue sections, as
opposed to smaller regions of interest, opens entirely new opportunities for
practicing pathologists. Media Cybernetics’ Image-Pro Premier software builds
upon the image analysis tools of their existing Image-Pro Plus software,
providing pathologists with exciting new quantitative capabilities. A 64-bit
operating environment provides the ability to view very large image formats. New
segmentation tools provide more precise biomarker concentration estimates.
Open and review large
images
Whole-slide imaging is now commonplace, accepted and very
affordable. From customized upright microscopes utilizing high speed stages and
image stitching software to purpose-built scanning devices, large format
imaging is a mainstay. The benefit is in the perspective obtained from an
entire tissue section, not just a localized region of interest. Overall
biomarker distribution is easier to interpret, and patterns within tissues are
more easily discerned. Image-Pro Premier now supports large file formats like
BigTIFF and Aperio’s .svs image file by allowing users to view entire
multi-resolution files and extract out individual sections to analyze. And, pathologists’
qualitative inspection of tissue is extended through use of Image-Pro Premier’s
local zooming and panning tools.
Figure 1: Open whole slide
images and extract out large sections to quantify.
In addition to supporting multi-resolution slide scanning
files, Image-Pro Premier software supports digital cameras from manufacturers
like QImaging and Lumenera, enabling pathologists to acquire, analyze and save
images in standard formats like JPEG and TIFF.
Biomarker expression
and localization
An emerging trend in pathology is the use of fluorescence
markers to locate the origin of biomarker expression within tissues more
accurately. Image-Pro Premier possesses tools that provide pathologists with the
ability to overlay a fluorescently-stained tissue sample on its IHC-stained
counterpart. Image comparison tools allow users to overlay fluorescent and
brightfield images. The combination of fluorescence and brightfield information
provides added insight into the precise location of biomarker origin, providing
pathologists with additional information about biomarker proliferation within
the tissue sample.
Precise and
repeatable biomarker quantification
A long-standing problem in pathology is accurate reporting
of biomarker concentration. The human eye is adept at pattern recognition
within multiple features and across tissues, but has been demonstrated to lack
the ability to detect subtle changes in intensity. The problem is compounded
when multiple specimens or sections are involved, and when background levels
vary within each tissue section. To remove the subjectivity presented by uneven
staining and individual bias, segmentation tools are used to classify the
amount of biomarker present via brightfield stain intensity.
Image-Pro Premier’s Smart Segmentation tool is employed to
detect these subtle shifts in concentration not just within a single image, but
across multiple images. Smart Segmentation takes into account changes in
background across the sample, both in the local area and across the entire
tissue section. The tool can be adjusted for various biomarkers, For example,
individual settings can be applied to a breast tissue panel stained for
biomarker expression of HER2, ER and/or PR.
Practically any visible biomarker can be quantified by Smart
Segmentation, extending pathologists’ quantitative reach. Evaluation of a
biomarker’s location and percent coverage may be determined through the
application of Smart Segmentation to the entire tissue section, or to regions
of interest within the section.
Figure 2: Smart Segmentation
is used to classify the amount of biomarker present.
Morphometry -the
shape of the future
The analysis of shapes, or morphometry has long been used to
define cell and cell organelle features more precisely. Image-Pro Premier
evaluates shape factor and cell-level morphometry to gain better understanding
of tissue dynamics and disease progression. This use of morphometry and shape
factor analysis in digital pathology is gaining in popularity. The concept involves
precise mathematical descriptions of patterns, organelles and other cellular
features within tissue sections. It is used to describe shapes that may fall
within a ‘normal’ or expected conformation and used to predict whether changes
in shape, such as the roundness of the cell nucleus, may indicate a change in
tissue pathology.
Much as a shape can be described in precise quantitative
terms, the resulting distribution can be analyzed for outliers, not just to see
what is present, but also to determine whether a cluster of shapes with unique
characteristics indicates an emergent trend or disease state. Morphometric
characteristics can be evaluated across an entire tissue sample or within one
or several regions of interest. Image-Pro Premier provides over fifty unique
morphometric descriptors; all are accessed through the application of Smart
Segmentation and the software’s Automatic Counting and Classification tools to
each biomarker under evaluation.
Figure 3: Quantify morphometric
characteristics of cells within a defined region.
Automate routines,
store results and save time
Generation of reams of quantitative data requires two
additional data management tools. Repetitive interaction with study samples
requires extra time on the technologist’s part. Managing the resulting data
places demands on data archival and retrieval methods. To facilitate the former
requirement, Image-Pro Premier provides a sophisticated visual macro and
scripting development environment. Novice users can create custom analytical
routines and experts can automate entire image capture routines, data generation,
analysis and reporting methodologies. With the use of batch processing, these
routines can be automatically applied to entire folders of images. The benefit
is that users can save and export images and analysis data share or later
revisit with their colleagues.
The promise of deeper tissue insight from the basic
beginnings of low magnification observation of tissues to today’s standard of
high resolution digital imagery of tissue samples has been delivered. The next
step of extracting quantitative, unbiased and reliable data from these images
is underway. Image-Pro Premier delivers the promise of new insights using
quantitative approaches, advancing the field of pathology’s already formidable
knowledge of disease and disease mechanisms.
Image-Pro Premier software is available from Media
Cybernetics and their reseller partners.
Learn more and request a free 14-day trial version from: www.mediacy.com/index.aspx?page=IP_Premier
