Mri: Basic Principles and Applications

Magnetic Resonance Imaging (MRI) is an integral component of medical imaging. Whilst new measurement techniques and applications continue to be developed nearly thirty years after the initial clinical scanners were installed the basic principles behind the measurement techniques remain as true today as then. This fifth edition of MRI Basic Principles and Applications presents the fundamental concepts of MRI in a clear and concise manner, minimizing the mathematical formalism yet providing a foundation to understand the results that are obtained with today s clinical scanners. This book:

Accessible introductory guide from renowned teachers in the field Provides a concise yet thorough introduction for MRI focusing on fundamental physics, pulse sequences, and clinical applications without presenting advanced math Takes a practical approach, including up–to–date protocols, and supports technical concepts with thorough explanations and illustrations Highlights sections that are directly relevant to radiology board exams Presents new information on the latest scan techniques and applications including 3 Tesla whole body scanners, safety issues, and the nephrotoxic effects of gadolinium–based contrast media

This is an ideal resource to help radiologists prepare for their exams and understand the underlying MR physics principles as efficiently as possible.

Preface

ABR Study Guide Topics

1. Production of Net Magnetization

1.1. Magnetic Fields

1.2. Nuclear Spin

1.3. Nuclear Magnetic Moments

1.4. Larmor Precession

1.5. Net Magnetization

2. Concepts of Magnetic Resonance

2.1. Radiofrequency Excitation

2.2. Radiofrequency Signal Detection

2.3. Chemical Shift

3. Relaxation

3.1. T1 Relaxation and Saturation

3.2. T2 Relaxation, T2∗ Relaxation and Spin Echoes

4. Principles of Magnetic Resonance Imaging 1

4.1. Slice Selection

4.2. Readout or Frequency Encoding

4.3. Phase Encoding

4.4. Data Acquisition Techniques

5. Principles of Magnetic Resonance Imaging 2

5.1. Frequency Selective Excitation

5.2. Composite Pulses

5.3. Raw Data and Image Data Matrices

5.4. Raw Data and k–Space

5.5. Signal To Noise Ratio and Tradeoffs

5.6. Reduced k–Space Techniques

5.7. Reordered k–Space Techniques

5.8. Other k–Space Filling Techniques

5.9. Phased–Array Coils

5.10. Parallel Acquisition Techniques

6. Pulse Sequences

6.1. Spin Echo Sequences

6.2. Inversion Recovery Sequences

6.3. Gradient Echo Sequences

6.4. Echo Planar Imaging Sequences

6.5. Magnetization–Prepared Sequences

7. Measurement Parameters and Image Contrast

7.1. Intrinsic Parameters

7.2. Extrinsic Parameters

7.3. Parameter Tradeoffs

8. Signal Suppression Techniques

8.1. Spatial Presaturation

8.2. Magnetization Transfer Suppression

8.3. Frequency–Selective Saturation

8.4. Non–Saturation Methods

9. Artifacts

9.1. Motion Artifacts

9.2. Sequence/Protocol–Related Artifacts

9.3. External Artifacts

10. Motion Artifact Reduction Techniques

10.1. Acquisition Parameter Modification

10.2. Triggering–Gating

10.3. Flow Compensation

10.4. Radial–based Motion Compensation

11. MR Angiography

11.1. Time–of–Flight MRA

11.2. Phase Contrast MRA

11.3. Maximum Intensity Projection

12. Advanced Imaging Applications

12.1. Diffusion

12.2. Perfusion

12.3. Functional Imaging

12.4. Ultra–High Field Imaging

12.5. Noble Gas Imaging

13. MR Spectroscopy

13.1. Additional Concepts

13.2. Localization Techniques

13.3. Spectral Analysis and Postprocessing

13.4. Ultra–High Field Spectroscopy

14. Instrumentation

14.1. Computer/Image Processor

14.2. Magnet System

14.3. Gradient System

14.4. Radiofrequency System

14.5. Data Acquisition System

14.6. Summary of System Components

15. Contrast Agents

15.1. Intravenous Agents

15.2. Oral Agents

16. Safety

16.1. Magnetic Field

16.2. Cryogens

16.3. Gradients

16.4. RF Power Deposition

16.5. Contrast Media

17. Clinical Protocols

17.1. General Principles of Clinical MR Imaging

17.2. Examination Design Considerations

17.3. Protocol Considerations for Anatomical Regions

17.4. Recommendations of Specific Sequences and Clinical Situations

18. References and Suggested Readings

Brian M. Dale, Ph.D. MBA is Zone Research Manager, MR R&D Collaborations, Siemens Medical Solutions, Inc. Brian is a younger colleague at Siemens of the previous co–author, Dr Mark Brown. Brian has a PhD in biomedical engineering from Case Western Reserve University in Cleveland, OH. His interests are in sequence programming and optimal design.

Mark A. Brown, Ph.D. is Senior Technical Instructor at Siemens Medical Solutions Training and Development Center. He received his Ph.D. in Physical Chemistry from Duke University, in Durham, NC. His research interests include relaxation and exchange phenomena and in vivo nuclear magnetic resonance spectroscopy and imaging.

Richard Semelka, MD, is Director of Magnetic Resonance Services, Professor, and Vice Chairman of Radiology at the University of North Carolina–Chapel Hill Medical School. He received his medical degree and residency training in radiology in his native Canada at the University of Manitoba, and completed a clinical research fellowship in MRI of the body at the University of California at San Francisco. Dr. Semelka has authored over 300 peer–reviewed articles, 12 textbooks including the Wiley Abdominal–Pelvic MRI and Current Clinical Imaging series and is an internationally acclaimed authority in the field.