Atlas of Virtual Colonoscopy (eBook)

Abraham H. Dachman, MD, is a nationally known specialist in abdominal imaging. He uses X-rays and advanced imaging equipment to visualize the structure and function of abdominal organs. This information is used to help diagnose disease, to assist in surgical planning, and to determine if treatments are effective. Dr. Dachman is known for his expertise in using computed tomography (CT scans) to create 3-D images of abdominal structures. This 3-D technology gives physicians an additional, valuable tool to better visualize tissue without performing an invasive procedure. He is a leading authority on virtual colonoscopy--using noninvasive CT technology to detect polyps and masses in the colon. In addition, he applies 3-D techniques to aid in the detection and staging of pancreatic cancer, and in the evaluation of tumor response to chemotherapy. An active researcher, Dr. Dachman has published several journal articles, book chapters, and books, including the first text on virtual colonoscopy, "The Atlas of Virtual Colonoscopy." In addition, he shares his knowledge about this emerging field through courses for radiologists who want to learn how to read virtual colonoscopy studies. He also has given presentations at dozens of scientific meetings around the United States.Dr. Andrea Laghi is a renowned professor at the University of Rome, and the author of various journal articles in the field of virtual colonoscopy.

Atlas of Virtual Colonoscopy 2
Foreword I 5
Foreword II 6
Preface 8
Acknowledgments 10
Contents 11
Contributors 13
Part I:Text 16
1: Virtual Colonoscopy: From Concept to Implementation 17
Early Development and Clinical Trials 17
Challenges to Gain Reimbursement 18
Future Challenges for Broader Implementation 19
References 20
2: Global Implementation of Computed Tomography Colonography 22
Virtual Colonoscopy in Argentina 22
About Colorectal Cancer in Argentina 22
About Virtual Colonoscopy 23
Conclusions 24
Computed Tomographic Colonography in Austria 25
Introduction 25
Implementation of Computed Tomographic Colonography in Austria 25
Research 25
Training and Education 26
Distribution and Reimbursement 26
CTC Consensus Statement of the Austrian Radiological Society and the Austrian Society of Gastroenterology and Hepatology 27
Conclusion 27
Computed Tomographic Colonography: Implementation in Belgium 28
Introduction 28
History: The Enthusiasm for a New Technique 28
Current Status: The Period of Validation 29
The Future: Need for Structured Education 29
Conclusion 30
Implementation of Computed Tomographic Colonography in Canada 30
Introduction 30
Canadian Health Care System 30
Funding for Physicians and Radiological Equipment 31
Epidemiological Importance of Colorectal Cancer in Canada 31
Screening Initiatives Canada Guidelines 32
Screening of Individuals at Higher Risk 32
Ontario 33
Manitoba and Alberta 33
Saskatewan, Quebec, and British Columbia 34
Remaining Provincial Initiatives 34
Uptake for Screening Across Canada 34
Inclusion of CTC in the Screening Guidelines for CRC 35
Ontario Health and Technology Assessment Centre Recommendations 36
Implementation of CTC in Canada 36
Interface with Gastroenterology in Canada 37
Reimbursement 38
Current Clinical Status of Computed Tomographic Colonography 38
The CTC Program at the Joint Department of Medical Imaging in Toronto 38
Future Directions 39
Computed Tomographic Colonography in France 39
Conclusion 40
Screening and Computed Tomographic Colonography: The German Experience 41
Geography and Demography 41
Health Care System 41
Medical Education 42
Radiation Protection 42
Screening Optical Colonoscopy 42
CT Colonography 43
Computed Tomographic Colonography: The Irish Experience 44
Introduction 44
The Boston Link 44
Access to CT Colonography in Ireland 45
CT Colonography and Ireland: 2010 and Beyond 45
Computed Tomographic Colonography in Israel 45
Computed Tomographic Colonography in Italy 47
Research 47
Education and Training 48
Political Situation 48
Computed Tomographic Colonography in Japan 49
Introduction 49
Current Status of CTC in Japan 49
Diagnosis of Superficial Colorectal Tumors Using CTC 50
Future Prospects of CTC Diagnosis in Japan 52
Acknowledgments 55
Additional Note on Categorization of Superficial Tumors 55
Global Implementation of Computed Tomographic Colonography in Korea 56
Computed Tomographic Colonography in Sweden 57
Acknowledgement 58
UK Implementation of Computed Tomography Colonography 59
Introduction 59
Early Research and Implementation 59
Further Development of CT Colonography Research in the UK 59
Current Implementation 60
UK Training Courses 61
Conclusion 61
References 61
3: Epidemiology and Screening of Colorectal Cancer 67
Epidemiology of Colorectal Cancer 67
CRC Pathogenesis 67
CRC Screening 68
Fecal Occult Blood Test 69
Flexible Sigmoidoscopy 69
Colonoscopy 69
CT Colonography 70
High-Risk Individuals 70
Family/Personal History 70
Familial Adenomatous Polyposis 71
Hereditary Nonpolyposis Colorectal Cancer 71
Peutz–Jeghers and Juvenile Polyposis Syndrome 71
Inflammatory Bowel Disease 72
CRC Screening Guidelines 72
Position Statement of the American Cancer Society, US Multisociety Task Force on Colorectal Cancer, and American College of R 72
Position Statement of the US Preventive Task Force 73
References 74
4: Implementation and Clinical Trials in the United States 76
Introduction 76
Colorectal Cancer: Screening Options 76
Clinical Background: Polyp Histology, Size, and Management 77
Early CTC 77
CTC Takes a Couple of Steps Backward 78
Department of Defense Trial Sets the Bar 78
2005 Meta-analyses Muddy the Waters 79
Definitive CTC Clinical Validation 80
ACRIN I/II 80
University of Wisconsin 80
National Naval Medical Center Colon Health Initiative 81
Walter Reed Army Medical Center 81
Non-US-Based Clinical Trials 81
Future Clinical Trials 82
Conclusion 82
References 83
5: Clinical Trials in Europe 85
Introduction 85
Trials Aimed at Assessing Performance of CTC with Different Protocols and Instrumentation 85
Trials Targeting Average-Risk Individuals 85
Trials Targeting Individuals at Increased Risk for CRC by Family History 86
Trials Targeting Individuals at Increased Risk by Personal History (Surveillance) 86
CTC in FOBT Positives 87
CTC in Patients with Alarm Symptoms 87
Conclusions 87
References 87
6: Patient Preparation and Tagging 89
Introduction 89
Diet 89
Fiber-Restricted Diet 89
Liquid Diet 89
Cathartic Preparation 89
Polyethylene Glycol-Based Electrolyte Solution 89
Bisacodyl Sodium 90
Sodium Phosphate 90
Magnesium Citrate 90
Current Practice 90
Fecal and Fluid Tagging 91
Barium-Based Agents 91
Ionic Iodine-Based Agents 91
Non-ionic Iodine-Based Agents 91
Electronic Cleansing 92
Artifacts 93
Different Cathartic Preparations and Tagging Protocols 93
ACRIN Trial 93
University of Wisconsin 94
Massachusetts General Hospital 95
Conclusion 95
References 95
7: Scheduling, Performing, and Reporting Computed Tomographic Colonography 97
Introduction 97
Screening CTC Requests 97
Documenting Site Quality Assurance 97
Selecting a Cathartic and Oral Tagging Agent: Educating Radiology Personnel 99
Training CT Technologists 101
Technologist Training in Colonic Insufflation 102
How to Insufflate 103
Minimizing Perforation Risk 104
When to Scout 104
When to Scan After Scout View 105
What to Do If Colonic Distension Is Suboptimal on the Scout View 105
After Completion of the Supine Scan 106
Post–Optical Colonoscopy Cases 108
Summary of Potential Complications of CTC 109
Addressing Radiation Dose Concerns 109
Radiologist Training Requirements 113
Reporting the CTC Exam Results 114
Summary 118
References 118
8: Computed Tomographic Colonography: Image Display Methods 120
Introduction 120
Primary 2D Interpretation 120
Workflow 120
Advantages 121
Disadvantages 124
Primary 3D Interpretation 124
Workflow 127
Advantages 129
Disadvantages 130
Combined 2D/3D Approach 130
Novel Display Methods 131
Virtual Pathology 132
Unfolded Cube Projection 135
Filet View and Panoramic Endoluminal Display (“Band” View) 137
Supine-Prone Image Synchronization 138
Electronic Cleansing and Computer-Aided Detection 139
References 140
9: Nonpolypoid Colorectal Neoplasia 142
Introduction 142
Definition and Terminology 142
Definition of Nonpolypoid Colorectal Neoplasia 142
Morphologic Subtypes of Nonpolypoid Colorectal Neoplasia 142
Epidemiology and Malignant Potential 143
Prevalence/Frequency of Nonpolypoid Colorectal Neoplasia 143
Malignant Potential of Nonpolypoid Colorectal Neoplasms 145
Detection with Colonoscopy 146
Detection with CT Colonography 146
Sensitivity of CT Colonography for Detecting Nonpolypoid Colorectal Neoplasms 148
Suggestions for Better Visualization of Nonpolypoid Colorectal Neoplasms on CT Colonography 150
Conclusion 151
References 151
10: Magnetic Resonance Colonography 153
Introduction 153
MR Colonography Requirements 153
Technique 153
Tesla MRI 153
Patient Preparation and Impact on Accuracy and Acceptance 154
Bowel Cleansing 154
Fecal Tagging 154
Bowel Distension 156
Spasmolytic Agents 158
Bright Lumen and Dark Lumen MR Colonography 158
MR Colonography Results 159
Conclusions and Future Perspectives 160
References 160
11: Extracolonic Findings 162
Introduction 162
Detection and Reporting of ECFs on CTC 162
Incidence and Cost Effectiveness of ECF Reporting 165
References 168
12: Computer-Aided Diagnosis in Computed Tomographic Colonography 170
Introduction 170
Why Should CTC Readers Use CAD and How Should It Be Used? 170
CAD Schemes for Detection of Polyps in CTC 171
Technical Development of CAD Schemes 171
False-Positive Reduction in a CAD Scheme 172
Overview of FP Reduction Techniques 172
FP Reduction with 3D MTANNs 172
Stand-Alone Performance of CAD Schemes 175
CAD Schemes Developed in Academia 175
Industry (Nonacademic) CAD Software 176
Evaluation of a CAD Scheme with Reader Trial False-Negative CTC Cases 176
CAD Stand-Alone Performance for Reader Trial False-Negative Cases 177
Analysis of Stand-Alone CAD FP Sources 177
Stand-Alone Detection of Flat Neoplasms by CAD 177
Morphologically Flat Neoplasms (Flat Lesions) in CTC 177
Limitations of Current CAD Schemes for Flat-Lesion Detection 178
Flat-Lesion Database 179
Development of a 3D MTANN for Flat Lesions 180
Evaluation of the Stand-Alone Performance of the MTANN CAD Scheme 180
Multi-reader/Multi-case (MRMC) Observer Performance Study 181
University of Chicago Observer Performance Study (Prior Trial Cases Re-read) 184
Conclusion and Authors’ Perspective 187
References 187
Part II:Atlas 190
13: Normal Anatomy 191
Six Colorectal Segments 191
Rectum 192
Sigmoid Colon 193
Descending Colon 194
Splenic Flexure 195
Hepatic Flexure 195
Transverse Colon 196
Ascending Colon 197
Cecum 198
Appendiceal Orifice 199
Ileocecal Valve 200
Virtual Dissection Normal Anatomy 203
References 204
14: Sessile polyps 205
15: Pedunculated Polyps 218
16: Diminutive Polyps 226
17: Flat Lesions 231
18: Stool, Diverticulosis 250
19: Masses 258
20: Pitfalls and Miscellaneous 271
Appendix 297
Index 302