Biomedical Engineering Reference
In-Depth Information
them. By claiming that classifi cations enable the cytodiagnosticians both
to identify and disregard cells (and other features on the slide), I do not
mean that they then forgot about what they had found on the slide. On the
contrary, they often said that they made a comprehensive assessment of the
whole slide when they fi nished screening the slide. However, the continuous
classifi cation of all that was present on the slide during screening allowed the
cytodiagnosticians to proceed. They could for example rather quickly classify
a group of cells as CIN I cells, mark them with the 'dotting thing' ('prickmoj'
in Swedish), and continue screening the slide. The process whereby cells,
bacteria and even artefacts positively fi tted into a classifi cation thus made it
possible to 'disregard' them for the moment, and proceed with screening,
looking for other cells that were similar to, or different from those already
classifi ed. When this process went smoothly, it took only about fi ve minutes
to screen the cervical cytology slide. However, if they were unable to classify
what they saw, they would also use the dotting thing, but would get stuck on
this group of cells: perhaps they would have to ask a colleague for advice.
The process of reaching an unequivocal accord between cells (and other
features) and classifi cations is clearly described in the example below during
screening:
Well, I look at the age, and then I know approximately how it should
look. I see the bacteria at once. When you put the slide under the
microscope, then you see what kind of bacteria there is, and then you
can put it aside. Yes, well (…) when I've decided what kind of bacteria it
is, then I can sort it out of the way. If I've seen that there are glandular
cells, that should be there, then I put it aside. Then it's only the ugly
cells (…) Yes, now I looked at this request form and it says there that
she is born -26 and takes no hormones. And then the sample should
look in a particular way. You have dry mucous membranes. You see that
right away, because it kind of fi ts. If she had looked like a young girl, yes
another kind of picture, then you would have reacted and thought it was
wrong, or if she takes hormones. But, it almost always fi ts when you put
in the slide, and then you don't think any more of it. She has no bacteria,
so I don't have to think more about
that
. This one is born -58 and she
has an IUD [intrauterine contraceptive device], and then they usually
have a lot of infl ammatory cells, a foreign thing in the body. And she has!
It's infl amed. It's probably not something she notices (…) and then I go
down and look at what's there, and there were cocci, they often have
them, those with IUDs. So, there are a lot of leucocytes.
An interesting issue about the relation between classifi cations, knowledge
and seeing was raised when the cytodiagnosticians discussed changes in the
general picture of cells over the years. For example, there was a consensus that
HPV (human papilloma virus) had increased and trichomonas and herpes had
almost disappeared. It was thought that eventually new cytodiagnosticians
