Acute Ischemic Stroke : Imaging and Intervention

by Gonzalez, R. G.

• ISBN13: 9783540252641
• ISBN10: 3540252649
• Edition: 1st
• Format: Hardcover
• Copyright: 2006-02-01
• Publisher: SPRINGER

Summary

This timely book provides basic, practical and up-to-date information on how to use imaging to diagnose and treat patients with acute ischemic stroke. Written by physicians from the Massachusetts General Hospital and faculty from the Harvard Medical School, the book distills years of experience in the day-to-day management of acute stroke patients, as well as leading-edge basic and clinical research, into a practical guide. With the growing awareness that modern CT and MR imaging can meaningfully improve the outcome of the acute stroke patient, this book provides the practical information to advance the capacities of providers in delivering the most advanced care for this disease.

Table of Contents

PART I Fundamentals of Acute Ischemic Stroke
Ischemic Stroke: Basic Pathophysiology and Neuroprotective Strategies
Aneesh B. Singhal
Eng H. Lo
Turgay Dalkara
Michael A. Moskowitz
Introduction	1	(1)
Mechanisms of Ischemic Cell Death	1	(7)
Excitotoxicity and Ionic Imbalance	3	(1)
Oxidative and Nitrosative Stress	3	(1)
Apoptosis	4	(2)
Inflammation	6	(1)
Peri-infarct Depolarizations	7	(1)
Grey Matter Versus White Matter Ischemia	8	(1)
The Neurovascular Unit	8	(2)
Neuroprotection	10	(1)
Stroke Neuroprotective Clinical Trials: Lessons from Past Failures	10	(2)
Identifying the Ischemic Penumbra	12	(1)
Combination Neuroprotective Therapy	13	(1)
Ischemic Pre-conditioning	13	(1)
Nonpharmaceutical Strategies for Neuroprotection	14	(2)
Magnesium	14	(1)
Albumin Infusion	14	(1)
Hypothermia	14	(1)
Induced Hypertension	15	(1)
Hyperoxia	15	(1)
Prophylactic and Long-term Neuroprotection	16	(1)
Conclusion	16	(11)
References	17	(10)
Causes of Ischemic Stroke
W. J. Koroshetz
R. G. Gonzalez
Introduction	27	(1)
Key Concept: Core and Penumbra	28	(2)
Risk Factors	30	(1)
Primary Lesions of the Cerebrovascular System	31	(2)
Carotid Stenosis	31	(1)
Plaque	31	(1)
Atherosclerosis Leading to Stroke: Two Pathways	31	(1)
Collateral Pathways in the Event of Carotid Stenosis or Occlusion	31	(1)
Transient Neurological Deficits	31	(1)
Intracranial Atherosclerosis	32	(1)
Aortic Atherosclerosis	32	(1)
Risk Factors for Atherosclerosis	33	(1)
Extra-cerebral Artery Dissection	33	(1)
Primary Cardiac Abnormalities	33	(2)
Atrial Fibrillation	33	(1)
Myocardial Infarction	34	(1)
Valvular Heart Disease	34	(1)
Patent Foramen Ovale	34	(1)
Cardiac Masses	34	(1)
Embolic Stroke	35	(2)
The Local Vascular Lesion	35	(1)
Microvascular Changes in Ischemic Brain	35	(1)
MCA Embolus	36	(1)
Borderzone Versus Embolic Infarctions	36	(1)
Lacunar Strokes	37	(2)
Other Causes of Stroke	39	(1)
Inflammatory Conditions	39	(1)
Venous Sinus Thrombosis	39	(1)
Vasospasm in the Setting of Subarachnoid Hemorrhage	39	(1)
Migraine	40	(1)
Primary Hematologic Abnormalities	40	(1)
Conclusion	40	(1)
PART II Imaging of Acute Ischemic Stroke
Unenhanced Computed Tomography
Erica C. S. Camargo
Guido Gonzalez
R. Gilberto Gonzalez
Michael H. Lev
Introduction	41	(1)
Technique	42	(3)
Physical Basis of Imaging Findings	45	(1)
Optimal Image Review	46	(2)
Window-Width (W) and Center-Level (L) CT Review Settings	46	(2)
Density Difference Analysis (DDA)	48	(1)
CT Early Ischemic Changes: Detection and Prognostic Value	48	(2)
Early Generation CT Scanners	48	(1)
Early CT Findings in Hyperacute Stroke	48	(1)
Prognostic/Clinical Significance of EIC	49	(1)
Aspects	50	(4)
Implications for Acute Stroke Triage	51	(1)
Reading CT Scans	52	(2)
Conclusion	54	(3)
References	54	(3)
Stroke CT Angiography (CTA)
Shams Sheikh
R. Gilberto Gonzalez
Michael H. Lev
Introduction	57	(2)
Background -- General Principles of CTA	59	(5)
Advantages and Disadvantages of CTA	59	(1)
Potential Advantages	59	(1)
Potential Disadvantages	59	(2)
CTA Scanning Technique: Pearls and Pitfalls	61	(2)
Single-slice Protocols	63	(1)
Multi-slice Protocols	63	(1)
Radiation Dose Considerations	63	(1)
CTA Protocol for Acute Stroke	64	(13)
General Considerations	64	(1)
Contrast Considerations	65	(1)
Contrast Timing Strategies	66	(4)
Post-processing: Image Reconstruction	70	(1)
Image Review	70	(1)
Maximum Intensity Projection	71	(1)
Multiplanar Volume Reformat	72	(1)
Curved Reformat	73	(1)
Shaded Surface Display	73	(1)
Volume Rendering	73	(4)
CTA Protocol for Acute Stroke	77	(2)
Accuracy and Clinical Utility of CTA in Acute Stroke	79	(4)
Optimal Image Review	79	(1)
Role of CTA in Acute Stroke	79	(4)
Future Directions	83	(1)
Conclusion	83	(4)
References	83	(4)
CT Perfusion (CTP)
Sanjay K. Shetty
Michael H. Lev
Introduction	87	(1)
CTP Technical Considerations	88	(3)
Comparison with MR-PWI	91	(1)
Advantages	91	(1)
Disadvantages	91	(1)
CTP: General Principles	92	(1)
CTP Theory and Modeling	92	(2)
CTP Post-Processing	94	(2)
Clinical Applications of CTP	96	(1)
CTP Interpretation: Infarct Detection with CTA-S1	96	(5)
CTP Interpretation: Ischemic Penumbra and Infarct Core	101	(6)
Imaging Predictors of Clinical Outcome	107	(1)
Experimental Applications of CTP in Stroke	107	(1)
Conclusion	108	(7)
References	108	(7)
Conventional MRI and MR Angiography of Stroke
David Vu
R. Gilberto Gonzalez
Pamela W. Schaefer
Conventional MRI and Stroke	115	(6)
Hyperacute Infarct	115	(2)
Acute Infarct	117	(1)
Subacute Infarct	117	(1)
Chronic Infarcts	118	(1)
Hemorrhagic Transformation	119	(1)
Conclusion	120	(1)
MR Angiogram and Stroke	121	(18)
Noncontrast MRA	122	(1)
TOF MRA	122	(2)
Phase-Contrast MRA	124	(2)
Contrast-Enhanced MRA	126	(1)
Image Processing	126	(1)
Extracranial Atherosclerosis and Occlusions	127	(3)
Intracranial Atherosclerosis and Occlusions	130	(1)
Dissection	131	(1)
Other Infarct Etiologies	132	(1)
Moya Moya	132	(1)
Vasculitis	133	(1)
Fibromuscular Dysplasia	133	(1)
Venous Infarct	134	(1)
Conclusion	134	(1)
References	135	(4)
Diffusion MR of Acute Stroke
Pamela W. Schaefer
A. Kiruluta
R. Gilberto Gonzalez
Introduction	139	(1)
Basic Concepts/Physics of Diffusion MRI	139	(5)
Diffusion Tensor Imaging (DTI)	142	(2)
Diffusion MR Images for Acute Stroke	144	(1)
Theory for Decreased Diffusion in Acute Stroke	144	(1)
Time Course of Diffusion Lesion Evolution in Acute Stroke	145	(2)
Reliability	147	(3)
Reversibility of DWI Stroke Lesions	150	(2)
Prediction of Hemorrhagic Transformation	152	(3)
Diffusion Tensor Imaging	155	(4)
Correlation with Clinical Outcome	159	(1)
Stroke Mimics	159	(1)
Nonischemic Lesions with No Acute Abnormality on Routine or Diffusion-Weighted Images	159	(1)
Syndromes with Reversible Clinical Deficits that may have Decreased Diffusion	159	(2)
Transient Ischemic Attack	159	(1)
Transient Global Amnesia	160	(1)
Vasogenic Edema Syndromes	161	(3)
Posterior Reversible Encephalopathy Syndrome (PRES)	161	(1)
Hyperperfusion Syndrome Following Carotid Endarterectomy	162	(2)
Other Syndromes	164	(1)
Other Entities with Decreased Diffusion	164	(1)
Venous Infarction	165	(1)
Conclusion	166	(7)
References	167	(6)
Perfusion MRI of Acute Stroke
Pamela W. Schaefer
William A. Copen
R. Gilberto Gonzalez
Introduction	173	(1)
Dynamic Susceptibility Contrast Imaging	174	(1)
PWI Using Endogenous Contrast Agents	175	(2)
Post-Processing of Dynamic Susceptibility Contrast Images	177	(5)
Reliability	182	(1)
Diffusion in Combination with Perfusion MRI in the Evaluation of Acute Stroke	182	(11)
Diffusion and Perfusion MRI in Predicting Tissue Viability	182	(7)
Perfusion MRI and Thrombolysis in Acute Ischemic Stroke	189	(1)
Diffusion and Perfusion MRI in Predicting Hemorrhagic Transformation of Acute Stroke	190	(2)
Correlation of Diffusion and Perfusion MRI with Clinical Outcome	192	(1)
Conclusion	193	(6)
References	193	(6)
Acute Stroke Imaging with SPECT, PET, Xenon-CT, and MR Spectroscopy
Mark E. Mullins
Introduction	199	(1)
SPECT	199	(3)
Advantages	201	(1)
Liabilities	201	(1)
PET	202	(2)
Advantages	203	(1)
Liabilities	204	(1)
Xe-CT	204	(1)
Advantages	205	(1)
Liabilities	205	(1)
MR Spectroscopy	205	(4)
Advantages	207	(1)
Liabilities	207	(1)
References	207	(2)
PART III Intervention in Acute Ischemic Stroke
Clinical Management of Acute Stroke
W.J. Koroshetz
R.G. Gonzalez
Introduction	209	(1)
History of Stroke Onset	209	(1)
Clinical Presentation	210	(1)
Emergency Management	211	(1)
General Medical Support	211	(4)
ABCs of Emergency Medical Management	211	(4)
Medical Evaluation	215	(1)
Neurologic Assessment	215	(4)
Intervention and Treatment	219	(1)
Conclusion	219	(2)
Suggested Reading	220	(1)
Intravenous Thrombolysis
Lee H. Schwamm
Introduction	221	(1)
Thrombosis and Fibrinolysis	221	(1)
Fibrinolytic Agents	222	(1)
Intravenous Fibrinolysis	223	(3)
Evidence-Based Recommendations for Acute Ischemic Stroke Treatment with Intravenous Fibrinolysis	226	(1)
Acute Ischemic Stroke Treatment with Intravenous t-PA	227	(6)
Conclusion	233	(4)
References	233	(4)
Endovascular Treatment of Acute Stroke
Raul G. Nogueira
Johnny C. Pryor
James D. Rabinov
Albert Yoo
Joshua A. Hirsch
Rationale	237	(1)
Technical Aspects	238	(13)
Pre-procedure Evaluation and Patient Monitoring	241	(2)
Procedural Technique	243	(1)
Chemical Thrombolysis	243	(1)
Mechanical Thrombolysis	244	(3)
New Mechanical Devices	247	(1)
Thrombolytic Agents	247	(3)
Adjunctive Therapy	250	(1)
Intra-arterial Thrombolysis Trials	251	(4)
Background	251	(1)
Anterior Circulation Thrombolysis	251	(1)
Posterior Circulation Thrombolysis	252	(1)
Combined Intravenous and Intra-arterial Thrombolysis	253	(2)
Grading Systems	255	(1)
Conclusion	255	(8)
Appendix: MGH Protocols for Intra-arterial Thrombolytics (Chemical and/or Mechanical) for Acute Stroke	256	(1)
Intra-arterial Inclusion Criteria	256	(1)
Absolute Exclusion Criteria	256	(1)
Relative Contraindications	257	(1)
Pre-Thrombolysis Work-up	257	(1)
Pre-Thrombolysis Management	257	(1)
Peri-Thrombolysis Management	258	(1)
Pre- and Post-Treatment Management	258	(1)
Protocol for Blood Pressure Control After Thrombolysis	258	(1)
Management of Symptomatic Hemorrhage After Thrombolysis	259	(1)
References	259	(4)
Epilogue: CT versus MR in Acute Ischemic Stroke	263	(2)
R. Gilberto Gonzalez
Subject Index	265