3 ms·
What about the radio signal used for MRI imaging, is it blocked by the skull as well? Or is it just strong enough to be able to penetrate the skull?
by est31 8y ago
What about the radio signal used for MRI imaging, is it blocked by the skull as well? Or is it just strong enough to be able to penetrate the skull?
- tbenst 8y agofMRIs use a crazy strong magnetic field—typically >= 3 Tesla. The signal that is measured is not electrical but rather the blood oxygen level. Effectively, this is a correlate of the metabolic expenditure of nearby neurons. Wass it is also like a low-pass filter except here it’s more like 0.5 Hz or slower. On the plus, you get much improved spatial resolution
- est31 8y agoMRIs use two magnetic fields, a static one and a dynamic one. And they use a radio signal according to the larmor frequency to excite the spin of the atoms. I was wondering about that radio signal component.