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Hmm... what does an MRI scanner update do? I would have thought a system like that would just record whatever it gets from its sensors and any updates needed wo

by Figs 12y ago

Hmm... what does an MRI scanner update do? I would have thought a system like that would just record whatever it gets from its sensors and any updates needed would only apply to the analysis and visualization software... Do the updates actually modify what the hardware does during scanning? Or, is it all painfully coupled because some sort of interactivity is required during scanning?

fencepost 12y ago
Probably improved image processing - noise removal, sharpness, could be a whole range of things, possibly down to something as seemingly simple as changing motor stepping for some of the actual moving parts.
btilly 12y ago
MRIs do not work like you think they do. A single measurement is that you magnetize the body in a particular pattern, then watch how that magnetic pattern fades. Then do it again in another pattern and repeat. Think of the patterns as being terms in a Fourier series, which you eventually will do a Fourier transform on to get the original thing. The name of the game, therefore, is to be able to get away with as few measurements as possible, and to be able to perform measurements here while still recovering from measurements there. Oh, and while we're at it, let's try not to be thrown off from things that tend to move around. Like arteries do every time another heartbeat comes through. So yes..there is a lot of interactivity in an MRI measurement.
EpicEng 12y ago
You may think they are simple machines which do one job and pretty much never need to be changed (not an unreasonable assumption), but that's not the case. I work in the medical device field and, well, you still have to sell instruments. To do that you need to beat the competition. To do that you need more features which make the doctor's/tech's life easier and the diagnosis more accurate. That doesn't mean upgrading is easy. At the 501k/PMA level it pretty much always requires a re-filing, so you try not to do it often. But you do improve the product over time.

by Figs 12y ago

fencepost 12y ago

Probably improved image processing - noise removal, sharpness, could be a whole range of things, possibly down to something as seemingly simple as changing motor stepping for some of the actual moving parts.

btilly 12y ago

MRIs do not work like you think they do. A single measurement is that you magnetize the body in a particular pattern, then watch how that magnetic pattern fades. Then do it again in another pattern and repeat. Think of the patterns as being terms in a Fourier series, which you eventually will do a Fourier transform on to get the original thing. The name of the game, therefore, is to be able to get away with as few measurements as possible, and to be able to perform measurements here while still recovering from measurements there. Oh, and while we're at it, let's try not to be thrown off from things that tend to move around. Like arteries do every time another heartbeat comes through. So yes..there is a lot of interactivity in an MRI measurement.

EpicEng 12y ago

You may think they are simple machines which do one job and pretty much never need to be changed (not an unreasonable assumption), but that's not the case. I work in the medical device field and, well, you still have to sell instruments. To do that you need to beat the competition. To do that you need more features which make the doctor's/tech's life easier and the diagnosis more accurate. That doesn't mean upgrading is easy. At the 501k/PMA level it pretty much always requires a re-filing, so you try not to do it often. But you do improve the product over time.