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Imaging and Tessla

Posted: Thu Dec 10, 2009 8:30 am
by ariehs
MRIs and Tessla levels

My first MRI was done on a 3T machine.
A more recent repeat of that scan was done on a 1.5T, and the images were CLEARLY inferior.

Another 1.5T machine I was scanned in recently, though, provided great images. It was a new 'open' MRI, though.

Is it worth hunting down a 10T machine if I can, or just ensuring al future scans are on 3Ts? Are all images from 1.5 'open' machines better than the older ones?

Does anyone know of a private radiology clinic in or around Montreal with a 3T or 10T or higher machine?

Posted: Thu Dec 10, 2009 11:43 am
by dignan
I believe the world's most powerful MRI used on humans is 9.4 tesla and is in Chicago. 7 tesla is the highest strength that is (somewhat) widely available, but I'm not sure about Montreal.

Posted: Thu Dec 10, 2009 12:28 pm
by Lyon
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Posted: Thu Dec 10, 2009 1:40 pm
by ariehs
It was just yesterday I was reading about this, and I was left with the distinct impression that 10T existed, though they were uncommon. I can't cite my source, though, as I don't remember where I was reading this, so maybe I'm just crazy.

Well, I *am* crazy, and I have MRI proof of brain damage :), but that's beside the point.

Anyway, does anyone think/know if it's worth the minor extra effort to find higher resolution machines or not? What about this 'open bore' design stuff? Does that actually improve image quality?

Posted: Thu Dec 10, 2009 1:46 pm
by Lyon
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Posted: Thu Dec 10, 2009 1:53 pm
by patientx
Actually, as a general rule, the open MRI machines usually produce lower quality images than the closed machines. Just by virtue of being open, you are further from the magnetic, so the field strength in the body tends to be less.

But nothing is absolute. MRI quality depends on many factors, the strength of the big magnet being one. There's also the gradient magnets, RF coils, etc. Besides the magnet strength, probably the biggest factor affecting image quality is the processing software. There's some pretty heavy duty signal processing done by the computers in order to generate the images. And this signal processing software can be different at different MRI facilities.

So, I think it's tough to say that a 3 Tesla machine is better than a 1.5 Tesla machine. All other things being equal, this would be true; but these things are not always equal.

From what I have seen, I think the 7T machines aren't numerous, and are used mainly used in research settings right now. I'm not sure many facilities have 3T machines, either. All my MRIs (at an MRI facility and at a hospital) have been on 1T machines.