Brian Atkins wrote:
> There have been recent advances in MRI resolutions using quantum coherence
> effects:
>
> http://www.princeton.edu/~wwarren/NMRintro
I've just skimmed the article, but my physical chemistry is really
rusty (never been very good in it, anyway).
So, how does this impact MRI microscopy?
IIRC, it's bottlenecked by the following things: probe absorbance
(separation of energy levels and hence their populability, requiring
multi-Tesla magnetic fields), the creation of absorbance conditions
(via the gradient coils) in the specimen voxel to be imaged, and
the number of nuclei in that voxel.
Because of this MRI microscopy likes very small samples
(mouse to insect sized), so you can get stronger fields
(however, strong enough fields will eventually kill you),
and you have less volume to form your gradients over (which
are assymetrical, and hence makes your voxels very
elongated). And of course, there is a limit to energy
density you can pump into a live biological target without
frying it.
I presume above technique allows us to get a stronger signal
from fewer nuclei, right? So how much resolution enhancement
are we getting for insect and mouse-sized samples, an order
of magnitude or less?
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