Definition of percent touching?

I have a question about the definition of „percent touching“.

Here our project:
We want to determine the cells at the border of a cell colony. To do so, we only want to count cells that have less than 70 percent touching.

What I have done:
I created a pipeline to identify primary objects by using a smoothed Dapi image. Than this image was used to determine secondary objects in an actin image.
If I now use MeasureObjectNeighbors I have the problem to specify: what is a neighbor?
Using Adjacent or expand until adjacent resulted in values from 0 to 7 (see attached pdf file). Sometimes the results from adjacent and expand until adjacent are the same and sometimes not.

If I want to determine neighbors within a specific distance (5, 10, 20 or 50 pixel) I got values from 4 to 100 percent touching, which makes more sense to me. If an cell is in the middle of an colony I would expect that the boundary of this cell has nearly 100 percent touching to other cells.

I read the definitions in cell profiler manual, but so far I can´t really understand the results I got.
Here my questions:
What is percent touching really telling me?
What is the meaning if an object has 1 or 7 percent touching after using adjacent or expand until adjacent?

I know that there are a lot of more things in the pipeline, these are only for later quantifications.

Thanks a lot for your help. Fell free to contact me if it doesn´t come clear what I want to say.

neighbors_percent touching.pdf (137 KB)

pipeline measure everything_cell neighbors adj_expand until adj_specific distances.cp (14.7 KB)

Hi Manuela,

I believe you are seeing the same bug reported here (Measure cells at the edge of clumps), which has been fixed in the code but not yet officially released.

A build of CellProfiler including this fix is available from here with the caveats mentioned (take note of the fact that pipelines made with the trunk build are not backwards compatible).


Thanks for your fast answer.
I down loaded the thrunk builds and now the results make more sense.

Best regards,