04 relajacion transversal
TRANSCRIPT
THOME
PHYSICAL PRINCIPLES
Signal Generation
THOME
nuclei, protons and spins
longitudinal relaxation T1
transverse relaxation T2
exitation and relaxation
relation between T1 and T2
signal generation
THOME
transverse relaxation T2
Spin - Spin relaxation
signal generation
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ZBo
signal generationtransverse relaxation T2
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signal generationtransverse relaxation T2
Y
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signal generationtransverse relaxation T2
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signal generationtransverse relaxation T2
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signal generationtransverse relaxation T2
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signal generationtransverse relaxation T2
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signal generationtransverse relaxation T2
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signal generationtransverse relaxation T2
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signal generationtransverse relaxation T2
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signal generationtransverse relaxation T2
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signal generationtransverse relaxation T2
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Signal
signal generationtransverse relaxation T2
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Signal
signal generationtransverse relaxation T2
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Signal
signal generationtransverse relaxation T2
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Signal
signal generationtransverse relaxation T2
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Signal
dephasing
signal generationtransverse relaxation T2
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S
time
Free Induction Decay signal
FID
T2
signal generationtransverse relaxation T2
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T2
S
T2
63%
definition T2:
the time that passes untill 63% of the original signal has been lost
time
signal generationtransverse relaxation T2
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T2
S
T2*
time
signal generationtransverse relaxation T2*
Due to magnetic inhomegeneities the transverse relaxation is lost faster !! T2 T2*
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signal generationtransverse relaxation T2
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transmitcoil
radiofrequencytransmitter
signal generationtransverse relaxation T2
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transmitcoil
radiofrequencytransmitter
180º
180º
signal generationtransverse relaxation T2
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180º
signal generationtransverse relaxation T2
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180º
signal generationtransverse relaxation T2
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180º
signal generationtransverse relaxation T2
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180º
signal generationtransverse relaxation T2
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180º
signal generationtransverse relaxation T2
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180º
signal generationtransverse relaxation T2
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180º
signal generationtransverse relaxation T2
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180º
signal generationtransverse relaxation T2
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180º
signal generationtransverse relaxation T2
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180º
signal generationtransverse relaxation T2
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180º
refocusing pulse
signal generationtransverse relaxation T2
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180º 180º
refocusing pulse
signal generationtransverse relaxation T2
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T2 envelope
signal generationtransverse relaxation T2
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in conclusion:
• T1 relates to magnetisation
• T2 relates to signal
signal generation
THOME
nuclei, protons and spins
longitudinal relaxation T1
transverse relaxation T2
excitation and relaxation
relation between T1 and T2
signal generation