NMR/MRI

Question 1

What does NMR give details on

Answer 1

H density
Spin-lattice interactions
Spin-spin interactions

Question 2

How does the spin-echo system work

Answer 2

1. Apply 90° pulse, switched off, T2 de phased
2. After TE/2 apply 180° pulse(spins start rephasing)
3. Envelope of the maxima of FID gives tissue relaxation T2

Question 3

What does phase expanding give us and how

Answer 3

2D image from FT

Question 4

What is an exhogenic contrast agent

Answer 4

External paramagnetic substance

Question 5

What is an endogenic contrast agent

Answer 5

Paramagnetic substance already present in the organism