3
Special Procedures
The advanced-level MRI examination will contain six questions on special procedures. The topics covered are
- MR angiography (MRA)
– Flow dynamics
– Time of flight (TOF) principles
– Phase contrast principles
- Cine
– Cardiac
– Musculoskeletal
Q23 A major advantage of MRA over conventional angiography is that:
| (a) | Images with both heavy T1 and T2 weighting can be produced |  |
| (b) | Multiple views can be produced from a single acquisition |  |
| (c) | Much smaller catheters are used |  |
| (d) | Less ionizing radiation is used |  |
Q24 The MRA sequence that is more sensitive to slow flow is:
| (a) | 3D inversion prepared |  |
| (b) | 3D time of flight |  |
| (c) | Multislice vascular |  |
| (d) | 2D time of flight |  |
Q25 The removal of signal from vessels in an MRA sequence is achieved by:
| (a) | Gradient moment nulling |  |
| (b) | Spatial presaturation |  |
| (c) | Spectral presaturation |  |
| (d) | a and b |  |
Q26 The following is (are) important in MRA sequences to minimize the loss of signal due to dephasing within a voxel:
| (a) | Long TR |  |
| (b) | Small voxels |  |
| (c) | Short TE |  |
| (d) | b and c |  |
Q27 Blood flow velocities are greater:
| (a) | Further away from the heart |  |
| (b) | At a vessel wall |  |
| (c) | At the center of a vessel |  |
| (d) | In a 3D time of flight sequence |  |
Q28 Single order gradient moment nulling does not compensate for:
| (a) | Accelerated flow |  |
| (b) | Reverse flow |
