Acute Ischemic Stroke (eBook)

Contents 6
PART I Fundamentals of Acute Ischemic Stroke 12
1 Ischemic Stroke: Basic Pathophysiology and Neuroprotective Strategies --- Aneesh B. Singhal, Eng H. Lo,Turgay Dalkara,Michael A. Moskowitz 12
1.1 Introduction 12
1.2 Mechanisms of Ischemic Cell Death 12
1.3 Grey Matter Versus White Matter Ischemia 19
1.4 The Neurovascular Unit 19
1.5 Neuroprotection 21
1.6 Stroke Neuroprotective Clinical Trials: Lessons from Past Failures 21
1.7 Identifying the Ischemic Penumbra 23
1.8 Combination Neuroprotective Therapy 24
1.9 Ischemic Pre-conditioning 24
1.10 Nonpharmaceutical Strategies for Neuroprotection 25
1.11 Prophylactic and Long-term Neuroprotection 27
1.12 Conclusion 27
References 28
2 Causes of Ischemic Stroke --- W.J. Koroshetz, R.G.González 38
2.1 Introduction 38
2.2 Key Concept: Core and Penumbra 39
2.3 Risk Factors 41
2.4 Primary Lesions of the Cerebrovascular System 42
2.5 Primary Cardiac Abnormalities 44
2.6 Embolic Stroke 46
2.7 Lacunar Strokes 48
2.8 Other Causes of Stroke 50
2.9 Conclusion 51
PART II Imaging of Acute Ischemic Stroke 52
3 Unenhanced Computed Tomography --- Erica C.S.Camargo,Guido González, R. Gilberto González,Michael H. Lev 52
3.1 Introduction 52
3.2 Technique 53
3.3 Physical Basis of Imaging Findings 56
3.4 Optimal Image Review 57
3.5 CT Early Ischemic Changes: Detection and Prognostic Value 59
3.6 ASPECTS 61
3.7 Conclusion 65
References 65
4 Stroke CT Angiography (CTA) --- Shams Sheikh, R. Gilberto González, Michael H. Lev 68
4.1 Introduction 68
4.2 Background –General Principles of CTA 70
4.3 CTA Protocol for Acute Stroke 75
4.4 CTA Protocol for Acute Stroke 88
4.5 Accuracy and Clinical Utility of CTA in Acute Stroke 90
4.6 Future Directions 94
4.7 Conclusion 94
References 94
5 CT Perfusion (CTP) --- Sanjay K. Shetty,Michael H. Lev 98
5.1 Introduction 98
5.2 CTP Technical Considerations 99
5.3 Comparison with MR-PWI 102
5.4 CTP:General Principles 103
5.5 CTP Theory and Modeling 103
5.6 CTP Post-Processing 105
5.7 Clinical Applications of CTP 107
5.8 CTP Interpretation: Infarct Detection with CTA-SI 107
5.9 CTP Interpretation:Ischemic Penumbra and Infarct Core 112
5.10 Imaging Predictors of Clinical Outcome 118
5.11 Experimental Applications of CTP in Stroke 118
5.12 Conclusion 119
References 119
6 Conventional MRI and MR Angiography of Stroke --- David Vu, R.Gilberto González,Pamela W. Schaefer 125
6.1 Conventional MRI and Stroke 125
6.2 MR Angiogram and Stroke 131
References 145
7 Diffusion MR of Acute Stroke --- Pamela W. Schaefer,A. Kiruluta, R. Gilberto González 148
7.1 Introduction 148
7.2 Basic Concepts/Physics of Diffusion MRI 148
7.3 Diffusion MR Images for Acute Stroke 153
7.4 Theory for Decreased Diffusion in Acute Stroke 153
7.5 Time Course of Diffusion Lesion Evolution in Acute Stroke 154
7.6 Reliability 156
7.7 Reversibility of DWI Stroke Lesions 159
7.8 Prediction of Hemorrhagic Transformation 161
7.9 Diffusion Tensor Imaging 164
7.10 Correlation with Clinical Outcome 168
7.11 Stroke Mimics 168
7.12 Nonischemic Lesions with No Acute Abnormality on Routine or Diffusion-Weighted Images 168
7.13 Syndromes with Reversible Clinical Deficits that may have Decreased Diffusion 168
7.14 Vasogenic Edema Syndromes 170
7.15 Other Entities with Decreased Diffusion 173
7.16 Venous Infarction 174
7.17 Conclusion 175
References 176
8 Perfusion MRI of Acute Stroke --- Pamela W. Schaefer,William A.Copen, R. Gilberto González 181
8.1 Introduction 181
8.2 Dynamic Susceptibility Contrast Imaging 182
8.3 PWI Using Endogenous Contrast Agents 183
8.4 Post-Processing of Dynamic Susceptibility Contrast Images 185
8.5 Reliability 190
8.6 Diffusion in Combination with Perfusion MRI in the Evaluation of Acute Stroke 190
8.7 Conclusion 201
References 201
9 Acute Stroke Imaging with SPECT, PET,Xenon-CT, and MR Spectroscopy --- Mark E. Mullins 206
9.1 Introduction 206
9.2 SPECT 206
9.3 PET 209
9.4 Xe-CT 211
9.5 MR Spectroscopy 212
References 214
PART III Intervention in Acute Ischemic Stroke 216
10 Clinical Management of Acute Stroke --- W.J. Koroshetz, R.G.González 216
10.1 Introduction 216
10.2 History of Stroke Onset 216
10.3 Clinical Presentation 217
10.4 Emergency Management 218
10.5 General Medical Support 218
10.6 Medical Evaluation 222
10.7 Neurologic Assessment 222
10.8 Intervention and Treatment 226
10.9 Conclusion 226
Suggested Reading 227
11 Intravenous Thrombolysis --- Lee H.Schwamm 228
11.1 Introduction 228
11.2 Thrombosis and Fibrinolysis 228
11.3 Fibrinolytic Agents 229
11.4 Intravenous Fibrinolysis 230
11.5 Evidence-Based Recommendations for Acute Ischemic Stroke Treatment with Intravenous Fibrinolysis 233
11.6 Acute Ischemic Stroke Treatment with Intravenous t-PA 234
11.7 Conclusion 240
References 240
12 Endovascular Treatment of Acute Stroke --- Raul G. Nogueira, Johnny C. Pryor, James D. Rabinov, Albert Yoo,Joshua A. Hirsch 243
12.1 Rationale 243
12.2 Technical Aspects 244
12.3 Intra-arterial Thrombolysis Trials 257
12.4 Grading Systems 261
12.5 Conclusion 261
References 265
Epilogue: CT versus MR in Acute Ischemic Stroke --- R. Gilberto González 268
Subject Index 270