Читать книгу Essentials of MRI Safety - Donald W. McRobbie - Страница 98

Movement through the static fringe field gradient dB/dz exposes tissue to a changing magnetic flux, and hence induces an electric field and current density. Restricting this discussion to the z‐direction only

(2.26a)

(2.26b)

The induced E and J are greatest for the highest level of dB/dz, i.e. close the scanner bore entrance, and scale with velocity. This mechanism is thought to be the cause for some of the acute sensory effects experienced around high field magnets (see Chapter 3).