fMRI - availablity/utility

Ajay Dhankhar ADHANKHA at biomed.med.yale.edu
Tue Oct 26 15:32:55 EST 1993


In <CFGx04.F9E at umassd.edu> rleary at UMASSD.EDU writes:

> 
>   
> Is functional/fast MRI yet available as a diagnostic tool as is
> a CAT scan? If one (or one's physician) wanted to have some fMRI studies/

It could be said that fast MRI IS available as a diagnostic tool.  Advanced
NMR Systems, MA have patented an upgrade of standard GE MRI scanners enabling
echoplanar MRI.  Also, most scanners can use other techniques not requiring
hardware (or significant software) modifications to acquire MRI's in times
significantly under a second (FLASH, GRASS etc).

Functional MRI is another ballgame.  The diagnostic capabilities of fMRI are 
still under development and a significant amount of spadework probably needs
to be completed before they become clinically relevant with the same confidence
level currently achieved by PET.  I would imagine that that would take at 
least a few more years 



> images done on a patient, could this be arranged without great difficulty?
> What about cost and waiting time? (I'm thinking about the Boston/New 
> England area but would also be interested if services were available elsewhere 
> - - e.g., Mayo Clinic, etc.) 
>


Like I said, functional studies on a patient using fMRI are not feasible.  
However, there are a few very respected research groups doing that kind of work
in the New England area.  The disadvantage of that is that they will obviously
use only those subjects relevant to their research.  The advantage is that it
won't cost anything and they'll actually pay you for the privilege of using
you as a subject!  I can think of at least 2 groups at Harvard, 2 at MIT, 2 at
Yale and several others.

 
>    Particularly interested in power of this technique/technology to reveal/
> indicate physical brain damage that previous techniques might not have been 
> unable to detect (in this regard I'd also like to know if "plain" MRI or 
> PET scanning is significantly more powerful/revealing than other predecessor 
> imaging techniques such as CAT scanning?
> 

There's no comparison.  CAT scans are always less revealing in functional 
studies (as compared to PET and of late to fMRI) and usually less powerful even
in anatomical diagnosis (compared to MRI).  Even with ultrafast CT, CAT does 
not even pretend to be a functionally diagnostic modality of much significance
any more.




>    Also, what about MEG - megnetoencephalography?
> 

Also very recent, and also not much in use clinically.  MEG has taken some 
criticism of late regarding its applicability.  


> 
>    Also - has physical evidence of brain damage attributable to drug abuse - 
> cocaine, LSD, amphetamines, etc. - ever been demonstrated using imaging 
> techniques? I remember seeing something (was it in the book Awakenings? - [the 
> author of which - the celebrated Dr. Sacks - got knocked in the context of 
> a review of another neuroscience book in Sunday's NY Times book review section])
> about a group of young people who literally blew their minds with some designer 
> drug - and I believe there were pictures/images showing this type of damage 
> in a real human brain.
> 

Somebody else has posted a response to this and I totally agree.  There is
bound to be damage from related factors and, with the lack of a control,
any structural damage would be hard to pin down to a specific cause.  I know
of studies of structural and metabolic damage due to chronic alcoholism in
humans, and the same due to cocaine infusions in cats.  I would be interested
in reading the study you've mentioned, if you can remember any citations
or whatever. 


Hope it helped.  You can email me if you need any specifics about things that
I've mentioned.


ajay dhankhar


________________________________________________________________________
Department of Molecular Biophysics and Biochemistry
Yale University School of Medicine
New Haven, CT 06510


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