SAQs - Chapter 9
1. Name three types of magnetism.
Diamagnetism, paramagnetism and ferromagnetism.
2. In which direction is B0 in a typical, permanent magnet imager?
Vertical.
3. What rule determines the direction of current flow through a coil, and the direction of the magnetic field that the current produces?
Right-hand thumb rule.
4. What is the maximum field strength allowed for clinical imaging of adults in the USA?
8.0 T.
5. What is the purpose of magnetic field shimming?
To correct for field inhomogeneity.
6. What is the purpose of shielding?
To reduce the fringe field.
7. What are the advantages of phased array coils?
Good SNR from small coils, combined with coverage.