Results interpretation: HELP!!

Are you looking for help on the interpretation of your microCT results?

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6 thoughts on “Results interpretation: HELP!!

  1. Max Chiu

    I have problems about “Euler number”
    “It is a measure of how many connections in a structure can
    be severed before the structure falls into two separate pieces.”
    but my data show negative number (ex. -557)
    how can I explain this data

    thanks a lot!!!!

    Max Chiu

    1. Martin

      Dear Max
      The Euler number (X) is related to the Betti numbers through the Euler-Poincaré formula:

      X = b0 – b1 + b2

      where b0 reports the number of components (i.e. particles in your structure), b1 reports the number of handles (i.e. the connectivity), and b2 reports the number of cavities enclosed within the structure. Thus, assuming that you have one solid component (b0=1) and no cavities (b2=0), b1 (the connectivity) can be calculated as

      b1 = 1 – X

      In your case with X = -557, the connectivity will be 558.

      More details can be found for instance in:
      Odgaard A., Bone 14:173-182, 1993


      1. Max Chiu

        Dear Martin
        Thank you so much for your reply. I really appreciate it!

        It is so difficult to understand what’s the meaning in that article for me but i’m still trying!

        thanks again for your help

        Max Chiu

  2. Ada

    I have a problem with results interpretation and I would love to hear your oppinion:
    there are two different groups of bone samples, one being control. In the 2nd group : I noted: slightly lower value of BV/TV. The Tb.N decreases, the Po.N(cl) and Po(cl) decreases drastically while Tb.Th and Tb.Sp. values seem to slightly increase. Is it a result of the bone expanding “sponge-like” and the whole structure “opening”?

    1. Martin

      Dear Ada

      A decrease in Tb.N is in line with an increase in Tb.Sp for a given Tb.Th. It is a bit difficult to tell from this information what really happens but I would guess that in group 2 some bone is lost, where you loose the thin structures. As a consequence, BV/TV is lower and your Tb.Sp is increased. Furthermore, the average Tb.Th of the remaining trabeuli could be the same or even increased.

      What do you mean by Po.N(cl). Is this a number of pores determined by component labeling?

      1. Ada

        Dear Martin,
        Thank you for your reply. Yes, I noted the “kind of” bone loss (as it is the post mortem process).
        The Po.N(cl) is the total number of discreet binarised closed pores within the VOI – number of connected assemblages of space voxels that are fully surrounded on all sides in 3D by solid voxels.
        Did I answer your question or you ment sth else?
        My problem is that although I understand the processes in the bone considering the definitions of parameters (like the dependance between Tb.N and Tb.Th), it is hard to actually SEE them. 🙂


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