Re: T. bataar eggs...again - Rowe

[Crpntr@ix.netcom.com (Kenneth Carpenter)]

You wrote: 

>
>
>Crpntr@ix.netcom.com (Kenneth Carpenter) writes:
>
>> hi tech (CAT, X-ray, MRI) have proven to be nearly a flop with work
>> on eggs.  It is important to remember that most of these techniques
>> rely on density differences.  Thus, if the bone is the same density
>> as the infilled matrix, then nothing shows up.
>
>Yes, CT (aka CAT) and standard X-rays rely on electron density
>differences in order to generate an image.  However, MRI typically
>measures the local chemical environment in which hydrogen atoms find
>themselves.  How much work has gone into using MRI on fossil samples?
>I would expect that minerals with differing hydrations would give you
>differing signals which could be extracted by a standard MRI system.
>Also, high energy MRI scanners look for differences in the chemical
>environments in which phosphorus atoms reside.  Does anybody have any
>idea how much residual phosphorus might remain in fossil bone as
>compared to the matrix?
>
>As an aside, emission computed tomographic techniques (e.g. PET,
>SPECT) cannot be used for these purposes since they require the
>injection of circulating radioisotopes.  Just in case anybody had any
>additional hopes I figured I should squash them early.  Sorry to be a
>party pooper :-)
>
>-- 
>Mickey Rowe     (rowe@lepomis.psych.upenn.edu)
>
>


I do not know how many specimens of eggs have been MRI'd.  I still have 
hopes that a way will be found to look inside eggs to determine 
conclusively whether or not there are embryo bones.  The best method 
remains, "Break it with a hammer!"


Kenneth Carpenter