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Introduction to diffusion tensor imaging : and higher order models /
The concepts behind diffusion tensor imaging (DTI) are commonly difficult to grasp, even for magnetic resonance physicists. To make matters worse, a many more complex higher-order methods have been proposed over the last few years to overcome the now well-known deficiencies of DTI. In Introduction t...
| Clasificación: | Libro Electrónico |
|---|---|
| Otros Autores: | , |
| Formato: | Electrónico eBook |
| Idioma: | Inglés |
| Publicado: |
Burlington :
Elsevier Science,
2013.
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| Edición: | 2nd ed. |
| Temas: | |
| Acceso en línea: | Texto completo |
Tabla de Contenidos:
- Front Cover; Introduction to Diffusion Tensor imaging; Copyright Page; Contents; Preface; Acknowledgments; 1 Basics of Diffusion Measurement; 1.1 NMR Spectroscopy and MRI Can Detect Signals from Water Molecules; 1.2 What is Diffusion?; 1.3 How to Measure Diffusion?; 1.3.1 We Need Gradient Systems to Measure the Diffusion Constant; 1.3.2 Gradient Pulses Change Signal Frequency Based on Locations of Water Molecules; 1.3.3 When a Pair of Dephasing and Rephasing Gradients are Applied, the Signal is Sensitized to Molecular Motions (Diffusio...; 2 Anatomy of Diffusion Measurement
- 2.1 A Set of Unipolar Gradients and Spin-Echo Sequence is Most Widely Used for Diffusion Weighting2.2 There are Four Parameters that Affect the Amount of Signal Loss; 2.3 There are Several Ways of Achieving a Different Degree of Diffusion Weighting; 3 Mathematics of Diffusion Measurement; 3.1 We Need to Calculate Distribution of Signal Phases by Molecular Motion; 3.2 Simple Exponential Decay Describes Signal Loss by Diffusion Weighting; 3.3 Diffusion Constant Can be Obtained from the Amount of Signal Loss But Not from the Signal Intensity
- 3.4 From Two Measurements, We Can Obtain a Diffusion Constant3.5 If There are More Than Two Measurement Points, Linear Least-Square Fitting is Used; References and Suggested Readings; 4 Principle of Diffusion Tensor Imaging; 4.1 NMR/MRI Can Measure Diffusion Constants Along an Arbitrary Axis; 4.2 Diffusion Sometimes has Directionality; 4.3 Six Parameters are Needed to Uniquely Define an Ellipsoid; 4.4 Diffusion Tensor Imaging Characterizes the Diffusion Ellipsoid from Multiple Diffusion Constant Measurements Along Diff...; 4.5 Water Molecules Probe Microscopic Properties of their Environment
- 4.6 Human Brain White Matter has High Diffusion AnisotropyReferences and Suggested Readings; 5 Mathematics of Diffusion Tensor Imaging; 5.1 Our Task is to Determine the Six Parameters of a Diffusion Ellipsoid; 5.2 We Can Obtain the Six Parameters from Seven Diffusion Measurements; 5.3 Determination of the Tensor Elements from a Fitting Process; References and Suggested Readings; 6 Practical Aspects of Diffusion Tensor Imaging; 6.1 Two Types of Motion Artifacts: Ghosting and Coregistration Error; 6.2 We Use Echo-Planar Imaging to Perform Diffusion Tensor Imaging
- 6.3 The Amount of Diffusion-Weighting is Constrained by the Echo Time6.4 There are Various k-Space Sampling Schemes; 6.5 Parallel Imaging is Good News for DTI; 6.6 Image Distortion by Eddy Current Needs Special Attention; 6.7 DTI Results may Differ if Spatial Resolution and SNR have been Changed; 6.8 Selection of b-Matrix; 6.8.1 Strength of the b-Value; 6.8.2 Orientation of Applied Gradients; 6.8.3 The Number of Gradient Orientations; 6.8.4 Which Protocol Should We Use?; 6.8.5 Protocol Setup Flowchart; References and Suggested Readings