Re: MRI Machines

John Larkin wrote:
On Tue, 24 Jun 2008 13:28:46 -0400, RFI-EMI-GUY
<Rhyolite@xxxxxxxxxxxx> wrote:

Well I spent a half hour of my life under the magnet of an "open" MRI machine yesterday. Still a bit claustrophobic. While I sort of understand the theory of the MRI, what I don't understand is what creates all the noise and racket. Any experts out there that can tell me whats going on?

Pulsed gradient coils. These are "small" 3-axis coils that sweep a
gradient field across your innards, modulating the nuclear resonant
frequencies of your molecules to produce the spatial resolution. These
are generally water-cooled, with ballpark 20 KW constant-current
drivers per axis, playing all sorts of weird waveforms.

They scanned my head last year, with the gradient coils around my head
like some horror mask: noisy and boring.

Any obvious neural effects from the scanning fields?

--
Dirk

http://www.transcendence.me.uk/ - Transcendence UK
Remote Viewing classes in London
.

Relevant Pages

  • Re: MRI Machines
    ... While I sort of understand the theory of the MRI, what I don't understand is what creates all the noise and racket. ... gradient field across your innards, ... They scanned my head last year, with the gradient coils around my head ...
    (sci.electronics.design)
  • Re: MRI Machines
    ... While I sort of understand the theory of the MRI, what I don't understand is what creates all the noise and racket. ... gradient field across your innards, ... They scanned my head last year, with the gradient coils around my head ...
    (sci.electronics.design)
  • Re: MRI Machines
    ... While I sort of ... gradient field across your innards, ... They scanned my head last year, with the gradient coils around my head ... the magnet quenching and getting burned in a puff of steam. ...
    (sci.electronics.design)
  • Re: MRI Machines
    ... While I sort of understand the theory of the MRI, what I don't understand is what creates all the noise and racket. ... gradient field across your innards, ... They scanned my head last year, with the gradient coils around my head ...
    (sci.electronics.design)
  • Re: MRI Machines
    ... While I sort of ... They scanned my head last year, with the gradient coils around my head ... rattle snakes waiting inside that MRI tube. ...
    (sci.electronics.design)