Just going through comments spreading MRI information (source: I work with MRI scanners). Nothing is spinning inside the MRI machine. CT scanners have an internal spinning component, but MRIs do not.
Thank you, I actually did not know that. While we are at it: what is causing the sounds? And how often do those machines have to be calibrated, as I believe the RF receivers (?) have to be super sensitive and accurate.
The sound is caused by ‘gradient coils’ that are being switched on and off at kHz frequency, which is in the audible range for humans. The sound is caused by those coils vibrating due to the interaction of the magnetic field with the electric current in the coils: they’re non magnetic but they still feel the ‘Lorentz force’. As far as calibration, there is a pre-scan step (which is one reason why MRIs can take awhile) used to optimize the RF settings to each patient. Patients come in many shapes and sizes so the settings have to be tuned to get a good image every time. I’m actually not sure of how often they need to be serviced, but it seems like the manufacturers are here checking on the machines pretty often!
I doubt it, obviously depending on the applied force.
Skin is rather tough to rip with a blunt tool so yeah, maybe the head was disconnected from the spine immediately, making him look like a giraffe spinning at 12 RPM round and round.
Nope, the detector is separate from the magnet - the magnet encircles the patient completely, and doesn’t move. I’m sure the magnetic field is affected slightly by the rotating machinery, but that should be consistent and predictable, and would be accounted for in the imaging algorithms.
Yeah I considered the supercooled electromagnert couldn’t possibly rotate, but I wasn’t sure if it could be modulated to change field directions or something. Didn’t seem very likely. Thanks for the confirmation.
So, if the MRI spins at 12 RPM, does the dude also spin at 12 RPM?
Asking for a friend.
Just going through comments spreading MRI information (source: I work with MRI scanners). Nothing is spinning inside the MRI machine. CT scanners have an internal spinning component, but MRIs do not.
Thank you, I actually did not know that. While we are at it: what is causing the sounds? And how often do those machines have to be calibrated, as I believe the RF receivers (?) have to be super sensitive and accurate.
The sound is caused by ‘gradient coils’ that are being switched on and off at kHz frequency, which is in the audible range for humans. The sound is caused by those coils vibrating due to the interaction of the magnetic field with the electric current in the coils: they’re non magnetic but they still feel the ‘Lorentz force’. As far as calibration, there is a pre-scan step (which is one reason why MRIs can take awhile) used to optimize the RF settings to each patient. Patients come in many shapes and sizes so the settings have to be tuned to get a good image every time. I’m actually not sure of how often they need to be serviced, but it seems like the manufacturers are here checking on the machines pretty often!
I imagine his head was plucked like a ripe tomato in the garden.
I doubt it, obviously depending on the applied force.
Skin is rather tough to rip with a blunt tool so yeah, maybe the head was disconnected from the spine immediately, making him look like a giraffe spinning at 12 RPM round and round.
Honestly fuck this website
Nope. Tomato theory hold up better.
The detector spins around the patient, but does the magnetic field spin too? I though not, but I’m not that certain.
Nope, the detector is separate from the magnet - the magnet encircles the patient completely, and doesn’t move. I’m sure the magnetic field is affected slightly by the rotating machinery, but that should be consistent and predictable, and would be accounted for in the imaging algorithms.
Oh, TIL. Thanks!
Yeah I considered the supercooled electromagnert couldn’t possibly rotate, but I wasn’t sure if it could be modulated to change field directions or something. Didn’t seem very likely. Thanks for the confirmation.