What is Stereology?

Stereology is simply the study of estimating geometrical quantities.

There are five general types of quantities that are explored in stereology.

  1. Number – The number of things, also known as a population, is a basic quantity that is often of interest to researchers. Determining the numbers of objects is not as simple as it may seem.
  2. Length – Length is a concept that is easy to understand, but not as easy to define formally. Length becomes tricky when considering the length of things that twist and turn in space.
  3. Surface – Surface is the same as surface area, but surface is used to refer to the area of a shape that isn’t flat, Note that the area of something that appears in a plane is usually called “profile area”.
  4. Volume – The volume of something is a measure of how it fills up space.
  5. Connectivity – A geometrical quantity. It has to do with the way things are connected into objects.

The word “stereology” has its origin in the original field of study – obtaining information from flat, two-dimensional images (stereo=two, ology=the study of).

In 1961, the journal Science carried the following announcement:

An International Society of Stereology (the science of three-dimensional interpretation of flat images) has been formed for the exchange of ideas concerning applicable research methods in microanatomy, cytology, ultrastructure studies, metallurgy, geology, astronomy, and cosmology. Inquiries are invited concerning membership, or the activities of the society. (Hans Elias, Chicago Medical School, 710 S. Wilcott Ave., Chicago 12)

There are many examples today of estimating geometric quantities that are 2-dimensional. The more challenging concepts deal with the estimation of 3-dimensional quantities based on the observation of 2-dimensional images.

Today, the field of stereology has evolved to include the study quantification in 3 dimensions. In fact, today the most common estimates are quantities in 3-dimensional material. Examples of this are: number of brain cells within a brain region, the length of capillaries, the volume of a tumor, as well as the percentage of quartz in granite.

In recent years, advent of design-based stereology has improved the accuracy and reliability of quantification in biological research. The application of design-based stereological methods to the analysis of the central nervous system as well as other organs has contributed considerably to our understanding of the functional and pathological morphology of the body.

Some research fields that employ stereological analysis include:

  • Neurobiology
  • Cell Biology
  • Pathology
  • Medicine
  • Anatomy
  • Ecology
  • Forestry
  • Metallurgy
  • Geology
  • Petrology

References

Science, New Series, Vol. 134, No. 3471 (Jul. 7, 1961), 39-40