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21.05.14 |
StefanDelorme
Division ofRadiology
Outline
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Computed tomography
•
How it works
•
Strengths
•
Weaknesses
•
Magnetic resonance imaging
•
How it works
•
Strengths
•
Weaknesses
•
Ultrasound
•
How it works
•
Strengths
•
Weaknesses
21.05.14 |
StefanDelorme
Division ofRadiology
CT: Strengths
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Reliable
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Geometrically correct
•
Fast
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Patient ease and comfort
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Minimal motion artifacts
•
4D imaging possible
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Density values
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Electron density with dual-energy CT
•
High spatial resolution
21.05.14 |
StefanDelorme
Division ofRadiology
CT: Weaknesses
•
Relatively low tissue contrast
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Artifacts in neighbourhood to metal
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Limited potential for functional imaging
•
Iionising radiation
21.05.14 |
StefanDelorme
Division ofRadiology
Outline
•
Computed tomography
•
How it works
•
Strengths
•
Weaknesses
•
Magnetic resonance imaging
•
How it works
•
Strengths
•
Weaknesses
•
Ultrasound
•
How it works
•
Strengths
•
Weaknesses
21.05.14 |
StefanDelorme
Division ofRadiology
What do we need for an MR image?
We need…
•
Atomic nuclei
•
Protons
•
Magnetic fields
•
Static fields
•
Gradient fields
•
RF fields
➡
= rotating magnetic fields
21.05.14 |
StefanDelorme
Division ofRadiology
Atomic nucleus
Magnetic
moment
Spin
Charge
+
+
+
+