Factors affecting signal intensisty
- Created by: Joel
- Created on: 12-03-15 14:57
View mindmap
- Factors affecting signal intensity
- Density of protons
- The time taken for the excited protons to return to their normal orientation, using up their extra energy.
- Contrast in type of tissue
- Specific pulse sequences can be selected to give a desired image eg. Weighted is best to show soft tissue. T2 weighted shows area which has been affected by disease e.g fluid area.
- Field strength of gradient coils
- The greater the number of H protons the larger the signal. In air and outer bone (no H) appear dark.
- RF pulse signal
- When a large gradient field is used, better resonance occurs over a smaller distance therefore better resolution of the image.
- Relaxation time
- Repeatedly exciting protons then allow them to relax allow us to see the differences between the tissue types.
- Sequence of RF pulse
- certain sequences of pulses can be chosen to give you the your target image. T1 is weighted more to show your body's tissue more and T2 for areas with fluids
- Density of protons
Comments
No comments have yet been made