The fringe field lines extend out of the ends of the bore of the magnet.

State three advantages and three disadvantages to a Superconducting MRI Magnet.  (.5 mark each = 3 marks) Advantages:                                                    Disadvantages:                                                                                                                                                                                                                                                                                                                                                                                                                                              

Antenna effect – Approximately 25-26cm is a critical length for a dipole conductor (wire or lead implant) in a patient at 1.5T/63.8Mhz

List three things that can adversely affect a patient’s thermo-regulatory system, specifically their body’s ability to dissipate heat.   (3 marks).

When acquiring a transverse/axial slice which gradient is used for slice selection?

What operating mode will not exceed 2W/kg?

What is the unit used for SAR RF absorption?

In the diffusion-weighted image and ADC map shown, area B appears bright on the DWI and dark on the ADC map. What type of diffusion characteristic does this indicate? 

Spectroscopy can be used to determine many pathologies in the brain. Which of the following pathologies is MR Spectroscopy not used to diagnose?

Each slice acquired in an MRI acquisition requires the application of a separate RF pulse containing frequencies that match the Larmor frequencies of the protons contained in the slice. The phenomenon of “cross-excitation” occurs when: