> My gut feeling is the resolution here wouldn't be usable for
> much other than curiosity. But PaulB certainly would know.
>

>>You are correct. The resolution would be quite worthless. This
>>would only be suitable to sell with snake oils, etc. No usefull
>>information could be obtained. The standard xray of  circa 1930
>>would be superior.


Not totally true  (surprisingly) I'm pleased to say.
Certainly the industry could easily produce snake-oil products but, AFAI can
see  it is also capable of much more than that.

- A web search reveals much EIT work being by reputable organisations and
with resolutions which depend on the number of electrodes.
- The results are different than for XRays rather than worse - horses for
courses.
- One advantage is the lack of ionising radiation (unlike X-Ray) and the
ability to produce quite high speed real time images.
- While resolutions are not ever going to be as high as MRI the cost is in
the order of two orders of magnitude less. The response times are also
faster than functional MRI can achieve. When used for brain imaging it is
likely that some useful real-time results can be achieved.
- Applications can include ongoing heart or lung action imaging - not
something one would like to have done with XRay.
- While X-Ray is not a suitable technology for indiscriminate or unregulated
use there may be applications for EIT which are - due to its essential
safety.
eg Psychologists would dearly LOVE their own internal non-invasive brain
activity monitoring system - albeit every so coarse in resolution. Would you
like to have this done to your brain with XRay :-) ?
- EIT results vary with "excitation" frequency and may allow some very
interesting differential
- Current research efforts are being directed to better resolution by data
processing based on known attributes of the scanned medium.
Vastly increased numbers of electrodes could produce substantial
improvements - this may be achievable by "clever" rather than brute force
techniques (cf resistive graphics tablets).
- I am aware of a similar technique used with success to detect cracks in
alumina smelting electrodes.

I'd be interested in Paul's comments.



RM