Mori Introduction to Diffusion Tensor Imaging

1. Auflage 2007
ISBN: 978-0-08-049576-7
Verlag: Elsevier Science & Techn.
Format: EPUB
Kopierschutz: 6 - ePub Watermark

E-Book, Englisch, 190 Seiten

The concept of Diffusion Tensor Imaging (DTI) is often difficult to grasp, even for Magnetic Resonance physicists. Introduction to Diffusion Tensor Imaging uses extensive illustrations (not equations) to help readers to understand how DTI works. Emphasis is placed on the interpretation of DTI images, the design of DTI experiments, and the forms of application studies. The theory of DTI is constantly evolving and so there is a need for a textbook that explains how the technique works in a way that is easy to understand - Introduction to Diffusion Tensor Imaging fills this gap.
* Uses extensive illustrations to explain the concept of Diffusion Tensor Imaging
* Easy to understand, even without a background in physics
* Includes sections on image interpretation, experimental design and applications

Autoren/Hrsg.

Mori, Susumu

Inhaltsverzeichnis

1;Cover;1
2;Introduction to Diffusion Tensor Imaging;4
3;Copyrightpage;5
4;Contents;6
5;Preface;10
5.1;ACKNOWLEDGEMENTS;14
6;Chapter 1: Basics of diffusion measurement;16
6.1;1.1 NMR SPECTROSCOPYANDMRI CAN DETECT SIGNALS FROM WATER MOLECULES;16
6.2;1.2 WHAT IS DIFFUSION?;18
6.3;1.3 HOW TO MEASURE DIFFUSION?;19
7;Chapter 2: Anatomy of diffusion measurement;28
7.1;2.1 A SET OF UNIPOLAR GRADIENTS AND SPIN-ECHO SEQUENCE IS MOST WIDELY USED FOR DIFFUSION WEIGHTING;28
7.2;2.2 THERE ARE FOUR PARAMETERS THAT AFFECT THE AMOUNT OF SIGNAL LOSS;28
7.3;2.3 THERE ARE SEVERAL WAYS OF ACHIEVING A DIFFERENT DEGREE OF DIFFUSION WEIGHTING;32
8;Chapter 3: Mathematics of diffusion measurement;34
8.1;3.1 WE NEED TO CALCULATE DISTRIBUTION OF SIGNAL PHASES BY MOLECULAR MOTION;34
8.2;3.2 SIMPLE EXPONENTIAL DECAY DESCRIBES SIGNAL LOSS BY DIFFUSION WEIGHTING;42
8.3;3.3 DIFFUSION CONSTANT CAN BE OBTAINED FROM THE AMOUNT OF SIGNAL LOSS BUT NOT FROM THE SIGNAL INTENSITY;42
8.4;3.4 FROM TWO MEASUREMENTS, WE CAN OBTAIN A DIFFUSION CONSTANT;45
8.5;3.5 IF THERE ARE MORE THAN TWO MEASUREMENT POINTS, LINEAR LEAST-SQUARE FITTING IS USED;46
9;Chapter 4: Principle of diffusion tensor imaging;48
9.1;4.1 NMR/MRI CAN MEASURE DIFFUSION CONSTANTS ALONG AN ARBITRARY AXIS;48
9.2;4.2 DIFFUSION SOMETIMES HAS DIRECTIONALITY;48
9.3;4.3 SIX PARAMETERS ARE NEEDED TO UNIQUELY DEFINE AN ELLIPSOID;50
9.4;4.4 DIFFUSION TENSOR IMAGING CHARACTERIZES THE DIFFUSION ELLIPSOID FROM MULTIPLE DIFFUSION CONSTANT MEASUREMENTS ALONG DIFFERENT DIRECTIONS;52
9.5;4.5 WATER MOLECULES PROBE MICROSCOPIC PROPERTIES OF THEIR ENVIRONMENT;54
9.6;4.6 HUMAN BRAIN WHITE MATTER HAS HIGH DIFFUSION ANISOTROPY;55
10;Chapter 5: Mathematics of diffusion tensor imaging;56
10.1;5.1 OUR TASK IS TO DETERMINE THE SIX PARAMETERS OF A DIFFUSION ELLIPSOID;56
10.2;5.2 WE CAN OBTAIN THE SIX PARAMETERS FROM SEVEN DIFFUSION MEASUREMENTS;58
10.3;5.3 DETERMINATION OF THE TENSOR ELEMENTS FROM A FITTING PROCESS;60
11;Chapter 6: Practical aspects of diffusion tensor imaging;64
11.1;6.1 TWO TYPES OF MOTION ARTIFACTS: GHOSTING AND COREGISTRATION ERROR;64
11.2;6.2 WE USE ECHO-PLANAR IMAGING TO PERFORM DIFFUSION TENSOR IMAGING;66
11.3;6.3 THE AMOUNT OF DIFFUSION-WEIGHTING IS CONSTRAINED BY THE ECHO TIME;68
11.4;6.4 THERE ARE VARIOUS k-SPACE SAMPLING SCHEMES;68
11.5;6.5 PARALLEL IMAGING IS GOOD NEWS FOR DTI;72
11.6;6.6 IMAGE DISTORTION BY EDDY CURRENT NEEDS SPECIAL ATTENTION;75
11.7;6.7 DTI RESULTS MAY DIFFER IF SPATIAL RESOLUTION AND SNR ARE NOT THE SAME;76
11.8;6.8 SELECTION OF b-MATRIX;78
12;Chapter 7: New image contrasts from diffusion tensor imaging: theory, meaning, and usefulness of DTI-based image contrast;84
12.1;7.1 TWO SCALAR MAPS (ANISOTROPY AND DIFFUSION CONSTANT MAPS) AND FIBER ORIENTATION MAPS ARE IMPORTANT OUTCOMES OBTAINED FROM DTI;84
12.2;7.2 SCALAR MAPS (ANISOTROPY AND DIFFUSION CONSTANT MAPS) AND FIBER ORIENTATION MAPS ARE TWO IMPORTANT IMAGES OBTAINED FROM DTI;85
12.3;7.3 THERE ARE TUBULAR AND PLANAR TYPES OF ANISOTROPY;87
12.4;7.4 DTI HAS SEVERAL DISADVANTAGES;90
12.5;7.5 THERE ARE MULTIPLE SOURCES THAT DECREASE ANISOTROPY;91
12.6;7.6 ANISOTROPY MAY PROVIDE UNIQUE INFORMATION;94
12.7;7.7 COLOR-CODEDMAPS ARE A POWERFUL VISUALIZATION METHOD TO REVEAL WHITE MATTER ANATOMY;98
13;Chapter 8: Limitations and improvement of diffusion tensor imaging;100
13.1;8.1 TENSORMODEL OVERSIMPLIFIES THE UNDERLYING ANATOMY;100
13.2;8.2 THERE ARE MORE SOPHISTICATED NON-TENSORŽ-BASED DATA PROCESSING METHODS, WHICH REQUIRE DIFFERENT DATA ACQUISITION PROTOCOLS;102
13.3;8.3 NON-TENSOR MODELS USUALLY REQUIRE HIGH VALUES;105
14;Chapter 9: Three-dimensional tract reconstruction;108
14.1;9.1 THREE-DIMENSIONALTRAJECTORIES CAN BE RECONSTRUCTED FROM DTI DATA;108
14.2;9.2 THERE ARE TWO TYPES OF RECONSTRUCTION TECHNIQUES;108
14.3;9.3 THERE ARE THREE STEPS IN THE TRACT PROPAGATION MODELS;109
14.4;9.4 SIMPLE STREAMLINE TRACKING CAN BE USED TO RECONSTRUCT A TRACT;110
14.5;9.5 THERE ARE MANY LIMITATIONS TO SIMPLE TRACT PROPAGATION METHODS;114
14.6;9.6 SEVERAL APPROACHES ARE PROPOSED TO TACKLE THE LIMITATIONS;115
14.7;9.7 TRACT EDITING USESMULTIPLE REGIONS OF INTEREST;121
14.8;9.8 BRUTE-FORCE APPROACH IS AN EFFECTIVE TECHNIQUE FOR COMPREHENSIVE TRACT RECONSTRUCTION;125
14.9;9.9 ACCURACY AND PRECISION ARE IMPORTANT FACTORS TO BE CONSIDERED;125
14.10;9.10 REPRODUCIBILITY OF TRACTOGRAPHY IS MEASURABLE;128
14.11;9.11 TRACTOGRAPHY REVEALS MACROSCOPIC WHITE MATTER ANATOMY;129
14.12;9.12 THERE ARE ROUGHLY THREE TYPES OF INFORMATION OBTAINED FROM TRACTOGRAPHY;130
14.13;9.13 HOWCAN WEVALIDATE TRACTOGRAPHY?;132
14.14;9.14 HOW SHOULD WE USE A TOOL WITH UNKNOWN ACCURACY?;134
14.15;9.15 QUANTIFICATION IS A KEY TO MANY TYPES OF TRACTOGRAPHY-BASED STUDIES;135
14.16;9.16 THERE ARE SEVERAL POSSIBLE REASONS THAT LEAD TO SMALLER (OR LARGER) RECONSTRUCTION RESULTS;136
15;Chapter 10: Quantification approaches;140
15.1;10.1 IMPROVEMENT OF CONVENTIONAL QUANTIFICATION APPROACHES;140
15.2;10.2 QUANTIFICATION OF ANISOTROPY AND TRACT SIZES BY DTI;145
16;Chapter 11: Application studies;164
16.1;11.1 BACKGROUND OF APPLICATION STUDIES OF DTI;164
16.2;11.2 EXAMPLES OF APPLICATION STUDIES;165
17;References and Suggested Readings;178
17.1;PREFACE;178
17.2;CHAPTER 3;179
17.3;CHAPTER 4;179
17.4;CHAPTER 5;180
17.5;CHAPTER 6;180
17.6;CHAPTER 7;181
17.7;CHAPTER 8;183
17.8;CHAPTER 9;183
17.9;CHAPTER 10;185
17.10;CHAPTER 11;186
18;Subject Index;190