However, 4.0T scanner can produce vertigo, nausea, HA s, metallic taste and magnetophosphenes. Flowing blood in a magnetic field results in an induced biopotential. Creates an increased T-wave amplitude.
Gradient fields can induce current or peripheral nerve stimulation.
Magnetophosphenes are induced by gradient fields at high field strength. Fast spin echo sequences use a lot of RF pulses and thus far generate the most heating. Loops of wire, ECG electrodes, metallic patches, etc. have burned patients during sequence acquisition. Always use hearing protection, especially at high field strength. As magnetic field strength increases, the resonant frequency rate increases.