Diffusion-Weighted MR Imaging (eBook)

Part I: Principles and Background 9
Chapter 1 10
Principles of Diffusion-Weighted Imaging (DW-MRI) as Applied to Body Imaging 10
1.1 Introduction 10
1.2 Basic Diffusion Concepts 11
1.3 Magnetic Resonance Measurement of Diffusion 12
1.4 Anisotropic Diffusion 13
1.5 Diffusion Measurements In Vivo 14
1.6 Effect of Perfusion and Low b-Valueon ADC Estimation 15
1.7 Effect of SNR and High b-Value on ADC Estimation 17
1.8 Multi-Exponential Diffusion in Tissues 19
1.9 Conclusion 22
References 22
Chapter 2 25
Techniques and Optimization 25
2.1 Introduction 25
2.2 Factors that Aff ect Image Quality Using EPI DW-MRI Acquisition 26
2.2.1 Image Signal-to-Noise (SNR) 26
2.2.2 Image Artefacts 26
2.3 Bulk Diffusion Phantoms 27
2.4 Optimizing Image Quality on Volunteer or Patient Studies 30
2.4.1 Fat Suppression 31
2.4.2 Single-Shot Acquisition vs. Multiple Signals Averaging 32
2.5 Optimization Strategies for the Selection of b-Values 33
2.5.1 Quantitative Data 33
2.5.2 Qualitative Data 34
2.6 Summary of Technique Optimization for DW-MRI in the Body 36
References 37
Chapter 3 39
Qualitative and Quantitative Analyses: Image Evaluation and Interpretation 39
3.1 Introduction 39
3.2 Qualitative Assessment of DW-MR Images 40
3.2.1 DW-MR Images Acquired Using Different b-Values 40
3.2.1.1 T2 Shine-Through 41
3.2.1.2 Diffusion Anisotropy 42
3.2.2 ADC Maps 43
3.2.3 Principles of Image Interpretation Using DW-MRI and ADC Maps 45
3.3 Quantitative ADC Evaluation 47
3.3.1 Quantitative ADC Evaluation by Regions of Interests 47
3.3.1.1 Summary Statistics 47
3.3.1.2 Voxelwise Analysis 47
3.3.2 Software for ADC Calculation 48
3.3.3Applying Quantitative ADCValues for Disease Characterization 48
3.3.4 Measurement Reproducibility 50
3.4 Image Display 50
3.4.1 Display of the b-Value DW-MR Images 50
3.4.2 Image Fusion 50
3.4.3 Diffusion-weighted Whole-body Imaging with Background Body Signal Suppression (DWIBS) 52
3.5 Conclusions 52
References 52
Part II: Non-Oncological Applications in the Body 54
Chapter 4 55
MR Neurography: Imaging of the Peripheral Nerves 55
4.1 Introduction 55
4.2 Concepts of MR Neurography 56
4.2.1 Conventional MR Neurography 56
4.2.2 Visualization of Nerves Using DW-MRI 57
4.2.3 Difference Between Diffusion-Weighted MR Neurography and Diffusion Tensor Imaging/Tractography 58
4.2.4 DWIBS for Diffusion-Weighted MR Neurography 58
4.3 Technical Aspects 59
4.3.1 Basic Parameter Settings 59
4.3.2 Fat Suppression 59
4.3.3 Post-Processing by Maximum Intensity Projection 60
4.3.4 Unidirectionally Encoded Diffusion-Weighted MR Neurography 61
4.4 Normal Anatomy 62
4.4.1 General Image-Based Peripheral Nerve Anatomy 62
4.4.2 Brachial Plexus 63
4.4.3 Lumbosacral Plexus 64
4.5 Clinical Applications of Diffusion-Weighted MR Neurography 64
4.5.1 Neurogenic Tumours 64
4.5.2 Trauma 66
4.5.3 Mechanical Nerve Compression 66
4.5.4 Inflammatory Processes 68
References 71
Chapter 5 72
Evaluation of Organ Function 72
5.1 Introduction 72
5.2 Effect of b-Values 73
5.3 Salivary Glands 74
5.3.1 Introduction 74
5.3.2 Imaging at Rest 74
5.3.3 Imaging During and After Stimulation 74
5.3.4 Comparison with Salivary Gland Scintigraphy 76
5.3.5 Practical Issues 77
5.3.5.1 Patient Inclusion/Preparation 77
5.3.5.2 Magnetic Resonance Scans 77
5.3.5.3 Types of Saliva Stimulation 78
5.4 Kidneys 79
5.4.1 Introduction 79
5.4.2 Technical Considerations 79
5.4.3 DW-MRI in Experimental Settings 80
5.4.4 DW-MRI in Healthy Native Kidneys 80
5.4.4.1 Kidneys of Foetuses and Children 80
5.4.4.2 Kidneys of Healthy Volunteers 81
5.4.5 DW-MRI in Patients 82
5.4.6 DW-MRI in Transplanted Kidneys 83
5.5 Upper Abdominal Applications 84
5.5.1 Introduction 84
5.5.2 DW-MRI for Functional Evaluationof the Liver 85
5.5.3 DW-MRI in the Pancreas 85
References 86
Chapter 6 88
DW-MRI Assessment of Diffuse Liver Disease 88
6.1 Background 88
6.1.1 Epidemiology of Chronic Liver Disease 88
6.1.2 Histopathological Classification of Liver Fibrosis 89
6.1.3 Non-invasive Diagnosis of Liver Fibrosis and Cirrhosis 89
6.2 Role of Conventional MR Imaging for the Diagnosis of Liver Fibrosis and Cirrhosis 89
6.3 Diffusion-Weighted Imaging for the Diagnosisand Quantification of Liver Fibrosis 89
6.3.1 DW-MRI Acquisition/Processing/Quantification for Liver Disease 90
6.3.1.1 DW-MRI Acquisition 90
6.3.1.2 DW-MRI Processing 90
6.3.2 Results in Liver Fibrosis and Cirrhosis 90
6.4 Diffusion-Weighted Imagingfor the Diagnosis of Hepatocellular Carcinoma 92
6.5 Limitations of DW-MRI 93
6.6 Future Directions 93
References 94
Part III: Oncological Applications in the Body 97
Chapter 7 98
DW-MRI for Disease Detection 98
7.1 Introduction 98
7.2 Principles of DW-MRI for Lesion Detection in Oncology 99
7.2.1 Influence of Pathologyon Disease Detection 99
7.2.2 Influence of Background Tissueon Disease Detection 100
7.3 Applications of DW-MRI for Tumour Detection in the Body 103
7.3.1 Focal Liver Lesions 103
7.3.2 Prostate Cancer 105
7.3.3 Uterine and Cervical Cancer 107
7.3.4 Peritoneal Disease 107
7.3.5 Pancreatic Tumours 107
7.3.6 Colorectal Cancers 110
7.3.7 Renal Tumours 110
7.3.8 Bladder Tumours 110
7.3.9 Oesophageal and Gastric Cancers 111
7.3.10 Lung Cancers 111
7.3.11 Breast Tumours 112
7.3.12 Head and Neck Tumours 113
7.4 Conclusion 113
References 113
Chapter 8 117
DW-MRI for Disease Characterization in the Abdomen 117
8.1 Introduction 117
8.2 Liver Diseases 118
8.2.1 Hepatic Cyst 118
8.2.2 Hepatic Abscess 118
8.2.3 Hepatic Haemangioma 120
8.2.4 Focal Nodular Hyperplasia 121
8.2.5 Hepatocellular Carcinoma 122
8.2.6 Liver Metastases 124
8.3 Biliary Tree and Gallbladder Tumours 125
8.3.1 Intra-hepatic Cholangiocarcinoma 125
8.3.2 Extra-hepatic Cholangiocarcinoma 126
8.3.3 Gallbladder Carcinoma 127
8.4 Pancreatic Tumours 127
8.4.1 Solid Pancreatic Tumours 127
8.4.1.1 Pancreatic Ductal Adenocarcinoma 127
8.4.1.2 Neuroendocrine Tumours 130
8.4.2 Cystic Pancreatic Tumours 130
8.4.2.1 Intra-ductal Papillary Mucinous Neoplasm (IPMN) 130
8.4.2.2 Mucinous Cystic Neoplasm 131
8.4.2.3 Serous Cystadenoma 133
8.4.2.4 Solid and Papillary Epithelial Neoplasms 134
8.4.2.5 Pseudocyst 134
8.5 Colorectal Carcinoma 134
8.6 Renal Tumours 134
8.7 DW-MRI for Nodal Characterizationin the Abdomen 137
8.8 Peritoneal Metastases 138
8.9 Conclusions 138
References 139
Chapter 9 142
DW-MRI for Disease Characterization in the Pelvis 142
9.1 Introduction 142
9.2 Prostate Cancer 143
9.2.1 Background 143
9.2.2 Technical Considerations 143
9.2.3 DW-MRI Properties of Prostatic Tissues 144
9.2.4 Tissue Characterization for Diagnosis and Staging 145
9.2.5 Characterizing Tumours for Disease Prognostication and Response Assessment 145
9.3 Rectal Cancer 146
9.3.1 Background 146
9.3.2 DW-MRI Characteristics of Rectal Cancer 146
9.3.3 Characterization of Lymph Nodes 146
9.4 Transitional Cell Carcinoma of the Urinary Bladder 146
9.4.1 Background 146
9.4.2 DW-MRI of Bladder Carcinoma 150
9.5 Uterine Malignancy 151
9.5.1 Tissue Characterization for Diagnosis 151
9.5.2 Tumour Staging 151
9.6 Cervical Cancer 152
9.6.1 DW-MRI Characteristics of Primary Tumour 152
9.6.2 Characterizing Lymph Nodes 152
9.7 Ovarian Cancer 153
9.8 Inflammatory Disease 153
9.9 Conclusions 153
References 153
Chapter 11 174
DW-MRI Assessment of Treatment Response to Minimally Invasive Therapy 174
11.1 Introduction 174
11.2 Minimally Invasive Treatments 175
11.3 The Advantages of DW-MRIin the Assessment of Tumour Responseto Minimally Invasive Therapies 175
11.4 Technical Considerationsand Image Analysis 176
11.4.1 Image Acquisition 176
11.4.2 Measurement Time Points 177
11.4.3 Image Analysis 177
11.4.4 Pre- and Post-Treatment ADC Evaluation 177
11.5 Application of ADC for the Assessment of Minimally Invasive Therapies in Oncology 178
11.5.1 Preclinical Studies 178
11.5.2 Clinical Studies 178
11.6 Future Developments 182
11.7 Conclusion 183
References 183
Chapter 12 185
Evaluation of Lymph Nodes Using DW-MRI 185
12.1 Introduction 186
12.3 Detection and Characterization of Lymph Nodes Using DW-MRI 188
12.3.1 Technical Requirements 188
12.3.2 Qualitative Analysis 192
12.3.3 Quantitative Analysis: ADC Measurement 193
12.4 Clinical Applications of Diffusion-Weighted MR Imaging of Lymph Nodes 195
12.4.1 Head and Neck 195
12.4.2 Lung 198
12.4.3 Upper Abdomen 198
12.4.4 Pelvis 198
12.4.4.1 Female Tumours 198
12.4.4.2 Prostate and Bladder Cancers 199
12.4.4.3 Colorectal Cancer 199
12.5 Potential Pitfalls and Limitations 199
12.6 Hybrid MR Imaging Techniques 200
12.7 Summary and Conclusions 201
Abbreviations 202
References 202
Chapter 13 205
Evaluation of Malignant Bone Disease Using DW-MRI 205
13.1 Introduction 205
13.2 Malignant Conditions of the Bones 206
13.3 Conventional Imaging for the Detection of Bone Involvement in Cancer 207
13.4 Considerations for Conventional MR Imaging and DW-MRI 208
13.4.1 Conventional MR Imaging 208
13.4.2 Diff usion-Weighted MR Imaging (DW-MRI) 208
13.4.2.1 Regional DW-MRI 208
13.4.2.2 Diff usion-Weighted Whole-Body Imagingwith Background Signal Suppression (DWIBS) 210
13.5 DW-MRI for the Detection and Characterization of Bone Involvement in Cancer 210
13.5.1 Normal Appearance of Bones on DW-MRI 210
13.5.2 DW-MRI Detection of Metastatic Bone Disease 211
13.5.3 DW-MRI for Distinguishing Between Benign and Malignant Causes of Vertebral Collapse 214
13.5.4 DW-MRI for the Evaluation of Marrow Involvement by Haematological Malignancies 217
13.6 Assessment of Treatment Response in Malignant Bone Disease 218
13.6.1 DW-MRI for Assessing Treatment Response in Bone Malignancies 219
13.7 Benign Conditions That May Mimic Malignant Disease on DW-MRI 220
13.7.1 Osteoarthritis 220
13.7.2 Fracture 220
13.7.3 Abscess 220
13.7.4 Benign Tumour 222
13.8 Conclusions 222
References 222
Chapter 14 225
Diffusion-Weighted Whole-Body Imaging with Background Body Signal Suppression (DWIBS) 225
14.1 Introduction 225
14.2 Concept of DWIBS 226
14.3 Reasons for the Feasibility of Free Breathing Imaging Acquisition in Body DW-MRI 227
14.4 Important Parameter Settings and Coil Selection for DWIBS 228
14.4.1 Imaging Plane 228
14.4.2 Fat Suppression 228
14.4.3 b-Value 230
14.4.4 Repetition Time 230
14.4.5 Coil Selection 232
14.5 Workfl ow and Post-Processing 232
14.5.1 Workfl ow 232
14.5.2 Post-Processing 234
14.5.2.1 Maximum Intensity Projection (MIP) 234
14.5.2.2 Volume Rendering (VR) 234
14.5.2.3 Fusion Images 235
14.6 DWIBS as a “Signal Intensity-Based” Diagnostic Tool 239
14.7 Pitfalls in DWIBS 241
14.8 Clinical Applications of DWIBS in Oncology 243
14.8.1 Tumour Detection and Staging 243
14.8.2 Monitoring Response to Therapy 243
14.8.3 Detection of Tumour Persistence or Recurrence 247
References 248
Part IV: Future Developments 251
Chapter 15 252
Multifunctional MR Imaging Assessments: A Look into the Future 252
15.1 Introduction 252
15.2 Uses of Multifunctional MR Imaging 253
15.3 Depiction of Tumour Biology 255
15.3.1 Improving the Visualization of Tumour Characteristics 255
15.3.2 Corroborating with and Validating Against Other Functional Imaging Techniques 256
15.4 Clinical Characterization of Disease 259
15.4.1 Disease Detection and Localization 260
15.4.2 Lesion Characterization 262
15.4.2.1 Cerebral Tumours 263
15.4.2.2 Prostate Cancer 264
15.4.3 Assessment of Therapy Response 265
15.4.4 Assessing Residual Disease When Relapse Is Suspected 267
15.5 Radiotherapy Planning 267
15.6 Drug Development 270
15.7 Challenges for Implementation 272
15.8 Conclusions 275
References 275
Chapter 16 278
The Potential of DW-MRI as an Imaging Biomarker in Clinical Trials 278
16.1 Introduction 278
16.2 The Challenges Faced in Bringing New Drugs to Market 279
16.3 The Process of Drug Development 280
16.3.1 Preclinical In Vivo Studies 281
16.3.2 Phase I Clinical Trials 281
16.3.3 Phase II Clinical Trials 281
16.3.4 Phase III Clinical Trials 281
16.4 Biomarkers for Drug Development 282
16.5 Imaging in Clinical Trials 283
16.6 Multi-Site Implementationof Imaging Techniques 283
16.6.1 Standardization of Image Acquisition 284
16.6.2 Quality Assurance and Quality Control 284
16.6.3 Standardization of Image Review and Analysis 285
16.7 DW-MRI in Drug Development 285
16.7.1 Prediction of Drug Efficacy 285
16.7.2 Early Assessment of Treatment Response 285
16.7.3 Evaluation of Drug-Response Characteristics 286
16.8 Role of DW-MRI in Preclinical Drug Development 286
16.9 Current Status of DW-MRI for Drug Development 286
16.10 Conclusions 287
References 287
Subject Index 289
List of Contributors 293
Medical Radiology 296
Medical Radiology 298