24 Oct 13
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Originally posted by sonhouseJust look at the size of that monster! No wonder the project took 7 years and cost 270 million dollars to build it.
http://phys.org/news/2013-10-world-powerful-mri-online.html
Ten times the resolution now, at 100 microns, whereas the older ones were accurate only to 1 millimeter. Still not reading individual neurons but getting closer!
Not only has it got higher resolution but the link implies that, unlike old MRI, it's magnetic field is strong enough to image signals from sodium or potassium nuclei as well as hydrogen nuclei and that is significant because the movement of ions of sodium and potassium are used in the electrical signals of brain neurons so that might make this new MRI give a lot more info on what is going on in the human brain.
24 Oct 13
1 edit
Originally posted by humyWhat surprises me is gaining ten times the res with just a 25% increase in magnetic field strength. Why isn't the increase in resolution only 25%, that is to say, linear with field strength?
Just look at the size of that monster! No wonder the project took 7 years and cost 270 million dollars to build it.
Not only has it got higher resolution but the link implies that, unlike old MRI, it's magnetic field is strong enough to image signals from sodium or potassium nuclei as well as hydrogen nuclei and that is significant because the movement of ions ...[text shortened]... ons so that might make this new MRI give a lot more info on what is going on in the human brain.
It is great that they can do that without having to have a 94 Tesla field for 10X resolution!
25 Oct 13
1 edit
Originally posted by sonhouse
What surprises me is gaining ten times the res with just a 25% increase in magnetic field strength. Why isn't the increase in resolution only 25%, that is to say, linear with field strength?
It is great that they can do that without having to have a 94 Tesla field for 10X resolution!
What surprises me is gaining ten times the res with just a 25% increase in magnetic field strength. Why isn't the increase in resolution only 25%, that is to say, linear with field strength?
I don't know but you got me thinking and then I noticed the link said this:
“...A more expensive wire material, niobium-tin, would in theory carry enough current at the same diameter to create fields up to 20 Tesla, but it is much more brittle than niobium-titanium and difficult to wind. ...”
Well, 20 Tesla is just slightly over 70% of 11.75 Tesla. Thus, all they have to do to get a 20 Tesla is to find a way to workaround all the difficulties of using niobium-tin wire to get much greater resolution still. And, if a 25% increase in Tesla gives a ten fold increase in resolution, then, if my mathematical approximations are about correct, a 70% increase would give roughly 250 times greater resolution and that would mean an improvement in resolution from 100 microns to about 400 nanometres which would be easily good enough to distinguish between individual neurons in the brain and even most of the connections between them!
Anyone: Is there anything wrong with my above extrapolation here? does the link inadvertently give a false premise? -my conclusion does seem to me to be rather optimistic!
25 Oct 13
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Originally posted by humyWell, it is clear the resolution limit is non-linear at least up to about 12 Tesla. It remains to be seen if that is just a local dip or if it would extend to 20 T. I have no idea what formula's there are for extrapolating MRI resolution.What surprises me is gaining ten times the res with just a 25% increase in magnetic field strength. Why isn't the increase in resolution only 25%, that is to say, linear with field strength?
I don't know but you got me thinking and then I noticed the link said this:
“...A more expensive wire material, niobium-tin, would in theory carry ...[text shortened]... link inadvertently give a false premise? -my conclusion does seem to me to be rather optimistic!
You probably saw the video of the frog being levitated by being immersed in about a 10 T field, levitated because EVERYTHING is magnetic to one extent or another, even oxygen atoms and such. So with 20 T maybe people would have to be held down or something🙂
25 Oct 13
Originally posted by sonhouse
Well, it is clear the resolution limit is non-linear at least up to about 12 Tesla. It remains to be seen if that is just a local dip or if it would extend to 20 T. I have no idea what formula's there are for extrapolating MRI resolution.
You probably saw the video of the frog being levitated by being immersed in about a 10 T field, levitated because EVE ...[text shortened]... even oxygen atoms and such. So with 20 T maybe people would have to be held down or something🙂
So with 20 T maybe people would have to be held down or something 🙂
I can just imagine it: A 20 T hospital MRI in the future: A patient is sent into the machine but some idiot forgets to tie him down and the patient becomes a lethal missile and is thrown by the magnetic field out of the machine and smashes through a window and is thrown outside and hits some astonished passers-by killing them and him.