Target Volume Determination 2015

StefanDelorme Division ofRadiology

StefanDelorme Division ofRadiology

StefanDelorme Division ofRadiology

Suitable nuclei for in-vivo MR

Precession

Protons

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Nucleus Spin 1 H 1/2

Magnetic moment

α

Water

31 P

1/2

ADP / ATP Na-K-Pump

23 Na 3/2

Precession with ω

14 N 13 C 19 F 3 He

1

1/2 1/2

Dental enamel

-1/2 129 Xe -1/2

1g (H 2

O) = 3.67 . 10 22 molecules

65 % water

StefanDelorme Division ofRadiology

StefanDelorme Division ofRadiology

StefanDelorme Division ofRadiology

Makroskopic magnetization

Precession

Resonant high-frequency excitation

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M 0

z´

B 0

B 0

• Larmor frequency

Flip angle α

B = 0

• ω Precession frequency • External magnetic field, rotating with ω ( B 1

ω = γ Β

field)

y´

• Spins feel a quasi-static field ➡ Deflection by the flip angle α

M 0

0

S

Σ

x´

=

B = B 0

B 1

N