4
Quality Control
There will be two questions on quality control in the advanced-level MRI examination. These will cover
- Slice thickness
- Spatial resolution
- Contrast resolution
- Signal to noise
- RF shielding
- Field homogeneity and shimming
Q68 If the slice thickness is reduced by a factor of 2, the factor by which the NSA must be increased to maintain the same SNR (all other factors remaining constant) is:
| (a) | 8 |  |
| (b) | 1.41 |  |
| (c) | 4 |  |
| (d) | 2 |  |
Q69 Changing the size of the voxel in the frequency direction will:
| (a) | Double the scan time |  |
| (b) |
