Sunday, June 19, 2011
Fact or Artifact?
Prior to last week, my only exposure to "artifacts" was something like this:
But last week at the lab, Vasily, my research supervisor Olga's husband, told me about biological artifacts. Here is a definition from Biology Online:
Artifact. Any visible result of a procedure which is caused by the procedure itself and not by the entity being analyzed. Common examples include histological structures introduced by tissue processing, radiographic images of structures that are not naturally present in living tissue, and products of chemical reactions that occur during analysis.
Vasily told me that the researcher has to be very careful to distinguish between what might seem like fantastically interesting results and an artifact. I was intrigued. So I looked up some articles on PubMed about these so-called artifacts. Here are some of my findings, along with some pretty cool images that illustrate the concept.
One type of article that kept coming up was about radiological artifacts. Basically, the idea is that the quality of a CT scan or MRI can be compromised, leading to "image artifacts" that can result in the improper diagnosis of a disease. For example, according to one paper I read*, there are several categories of radiological artifacts. The artifact type that I understood the best (the others had to do with rather sophisticaed nuclear technology) results from motion. If there is either involuntary (i.e., sneezing, heart beating) or voluntary (i.e., swallowing) movement, there could be distortions or shadowing on the film. Above is an example of a artifacts pictured in the paper.
So what's the point, other than looking at cool cell stainings (which is fun on it's own, in my opinion)? The point is that as a scientist, and as a clinician, you have to be cognizant of what is normal. And then when results come back that are abnormal, you take a close look to make sure that there is not an alternate explanation other than true abnormality (or perhaps an amazing discovery, in the case of research). It's always about questioning things. That's the nature of science, isn't it? I think so, at least.
* Popilock, R., Sandrasagaren, K., Harris, L., and Kaser, K.A. (2008). CT artifact recognition for the nuclear technologist. J. Nucl. Med. Technol. 36, 79-81.
**Seeberger, K.L., Eshpeter, A., Rajotte, R.V., and Korbutt, G.S. (2009). Epithelial cells within the human pancreas do not coexpress mesenchymal antigens: epithelial-mesenchymal transition is an artifact of cell culture. Lab. Invest. 89, 110-121.