Re: T. bataar eggs...again

[rowe@lepomis.psych.upenn.edu (Mickey Rowe)]

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)