Imaging of the Pancreas (eBook)

All authors have published extensively in pancreatitis. Drs. Balthazar and Megibow have developed a classification system of acute pancreatitis used world-wide; Professor Pozzi-Mucelli is the Chairman of Radiology at one of the largest pancreatic centres in Europe.

Foreword 6
Preface 7
Table of Contents 9
Acute Pancreatitis 11
1 Pathophysiology of Acute Pancreatitis 12
1.1 Introduction 12
1.2 Etiology 12
1.2.1 Mechanical Etiology 13
1.2.1.1 Biliary Calculi 13
1.2.1.2 Pancreatic Obstruction from Neoplasm and Ascariasis 13
1.2.1.3 Congenital Anomalies – Pancreas Divisum 14
1.2.1.4 Trauma 14
1.2.2 Metabolic Etiology 14
1.2.2.1 Alcohol 14
1.2.2.2 Hypertriglyceridemia 15
1.2.2.3 Hypercalcemia 15
1.2.2.4 Post Cardiac Surgery 16
1.2.3 Miscellaneous Etiologies 16
1.3 Biochemical Pathogenesis of Acute Pancreatitis 16
1.3.1 Enzyme Co-localization and Mediators of Infl ammation 16
1.3.2 Mediators of Inflammation in Acute Pancreatitis 18
1.3.3 Systemic Manifestations of Inflammation in Acute Pancreatitis 20
References 21
2 Clinical Aspects of Acute Pancreatitis: Features, Prognosis and Use of Imaging Findings in Therapeutic Decision Making 23
2.1 Features of Acute Pancreatitis 23
2.2 Prognosis and Severity 24
2.2.1 Clinical Assessment of Severity 25
2.2.2 Laboratory Assessment of Severity 25
2.2.3 Radiologic Assessment of Severity 27
2.3 Timing and Use of Imaging in Therapeutic Decision Making 27
2.3.1 At Time of Diagnosis 27
2.3.1.1 Identification of Gallstones 27
2.3.1.2 Confirmation of Acute Pancreatitis 28
2.3.1.3 Assessment of Severity 28
2.3.2 During the First Week and Thereafter 29
2.3.2.1 Interstitial Pancreatitis 29
2.3.2.2 Necrotizing Pancreatitis 30
2.3.2.3 Infected Pancreatic Necrosis 32
2.3.2.4 Sterile Pancreatic Necrosis 35
2.3.2.5 Organized Necrosis 35
2.3.3 Venous Thrombosis and Solid Organ Involvement 36
2.3.4 Acute Hemorrhage 37
2.4 Summary 38
References 38
3 The Role of Ultrasound in Acute Pancreatitis 41
3.1 Introduction 41
3.2 Diagnosis 41
3.2.1 Size of the Pancreas 42
3.2.2 Echotexture of the Pancreas 42
3.2.3 Focal Changes 43
3.3 Extra-glandular Changes 44
3.3.1 Fluid Collections 44
3.3.2 Pancreatic Ascites 45
3.4 Etiologic Diagnosis 46
3.4.1 Gallstones 46
3.4.2 Biliary Ducts Stones 46
3.4.3 Idiopathic Pancreatitis 48
3.5 Clinical Evaluation 48
3.5.1 Severity Grading 48
3.5.2 Resolution of Acute Pancreatitis 49
3.6 Complications 49
3.6.1 Glandular Infections 49
3.6.2 Pseudocysts 50
3.6.3 Vascular Complications 52
3.7 Conclusions 52
References 52
4 The Role of Computed Tomography 56
4.1 Introduction 56
4.2 Pathophysiology 57
4.3 Clinical Signifi cance of Pancreatic Necrosis 59
4.4 Classification of Pancreatitis 59
4.5 Diagnosis of Acute Pancreatitis 60
4.5.1 Clinical and Laboratory Features 60
4.6 CT Diagnosis 61
4.6.1 Technical Considerations 61
4.6.2 Normal Pancreas 61
4.6.3 Diagnostic CT Features of Acute Pancreatitis 62
4.6.4 Limitations in the CT Diagnosis 65
4.6.5 Less Common CT Presentations 65
4.6.5.1 Segmental Pancreatitis 65
4.6.5.2 Groove Pancreatitis 65
4.6.5.3 Autoimune Pancreatitis 67
4.6.5.4 Acute Exacerbation of Chronic Pancreatitis 67
4.7 Staging of Acute Pancreatitis 68
4.7.1 Clinical and Laboratory Evaluation 68
4.7.2 Numerical Systems 69
4.8 CT Staging 70
4.8.1 CT Severity Index 72
4.8.2 Limitations and Pitfalls of CT Staging 72
4.9 Complications of Acute Pancreatitis 73
4.9.1 Intermediate Complications 75
4.9.1.1 Infected Pancreatic Necrosis 75
4.9.1.2 Pancreatic Abscess 75
4.9.1.3 Pancreatic Pseudocysts 76
4.9.2 Other Complications 77
4.10 Late Complications 78
4.10.1 Vascular and Hemorrhagic Complications 78
4.10.2 Pancreatic Ascites 80
4.11 Summary 81
References 81
5 Magnetic Resonance Imaging of Acute Pancreatitis 85
5.1 Introduction 85
5.2 MRI Protocol 86
5.2.1 General Principles of MRI of the Pancreas 86
5.2.2 Breath-hold Imaging 86
5.2.3 Non-breath-hold Imaging 86
5.2.4 Patient Preparation 87
5.2.5 Protocol 87
5.2.6 Secretin-MRCP (S-MRCP) 88
5.2.7 Intravenous Contrast 89
5.3 Role of MRI of Acute Pancreatitis 91
5.3.1 Underlying Causes of Pancreatitis 91
5.4 MRI Findings in Acute Pancreatitis 91
5.4.1 Normal Pancreas 91
5.4.2 Mild (Edematous) Pancreatitis 92
5.4.3 Severe (Necrotizing) Pancreatitis andComplications 94
5.4.4 Pancreatic Necrosis 95
5.4.5 Hemorrhage 98
5.4.6 Peripancreatic Collections 99
5.4.7 Pseudocysts 100
5.4.8 Vascular Complications 102
5.4.9 Imaging Features of Autoimmune Pancreatitis 103
5.5 Emerging MRI Techniques 106
5.5.1 Perfusion Imaging 106
5.5.2 MR Spectroscopy 107
5.5.3 Diffusion-Weighted Imaging 107
5.6 Conclusion 108
References 108
Pancreatic Trauma 111
6 Pancreatic Trauma 112
6.1 Introduction 112
6.2 Clinical Classifi cation of Pancreatic Injury 112
6.3 Imaging Diagnosis 113
6.3.1 Computed Tomography 113
6.3.1.1 CT Technique 113
6.3.1.2 CT Findings 114
6.3.2 Magnetic Resonance Imaging 116
6.3.3 Other Imaging Tests 118
6.4 Clinical Follow-Up 118
6.5 Accuracy of Imaging Studies in Pancreatic Trauma 118
References 118
Chronic Pancreatitis 120
7 Pathophysiology of Chronic Pancreatitis 121
7.1 The Role of Alcohol in Chronic Pancreatitis: Old and New Concepts 121
7.2 A Common Pathogenetic Mechanism: Ductal Obstruction 122
7.3 The Causes of Ductal Obstruction: “Inflammatory Pancreatic Diseases” 123
7.3.1 Pancreatitis Associated with Sphincter of Oddi Dysfunctions and Biliary Lithiasis 124
7.3.2 Pancreatitis Associated with Cystic Dystrophy of the Duodenal Wall – Groove Pancreatitis 124
7.3.3 Autoimmune Pancreatitis 125
7.3.4 Pancreatitis Associated with Gene Mutations 125
7.3.5 Pancreatitis Associated with Pancreatic and Peripancreatic Anomalies 126
7.3.6 Other Causes 127
References 127
8 Clinical Aspects of Chronic Pancreatitis: Features and Prognosis 132
8.1 The Different Clinical Aspects of “Inflammatory Pancreatic Diseases” 132
8.1.1 Pancreatitis Associated with Sphincter of Oddi Dysfunctions (Sod) and Biliary Lithiasis 133
8.1.2 Pancreatitis Associated with Cystic Dystrophy of the Duodenal Wall (or Groove Pancreatitis) 134
8.1.3 Autoimmune Pancreatitis 134
8.1.4 Pancreatitis Associated with Slow-Growing Pancreatic and Biliary Tumours 134
8.1.5 Pancreatitis Associated with Pancreatic Anomalies 135
8.1.6 Pancreatitis Associated with Gene Mutation 135
8.1.7 Pancreatitis Secondary to Sequelae of Acute Necrotizing Pancreatitis 136
8.2 Natural History of Chronic Pancreatitis and Prognosis 136
References 137
9 The Role of Ultrasound 141
9.1 Ultrasonographic Features 141
9.1.1 Pancreatic Gland Changes 141
9.1.1.1 Size, Shape and Contour 141
9.1.1.2 Echogenicity, Parenchymal Texture andCalcifi cations 143
9.1.2 Pancreatic Duct Changes 143
9.1.2.1 Caliber and Contour 143
9.1.2.2 Intraductal Calculi 145
9.2 Ultrasonographic Diagnosis 145
9.2.1 Severity 146
9.2.1.1 Early Stage 146
9.2.1.2 Advanced Stage 146
9.2.2 Etiology 147
9.2.2.1 Obstructive Chronic Pancreatitis 147
9.2.2.2 Non-obstructive Chronic Pancreatitis 147
References 150
10 The Role of Computed Tomography 151
10.1 Relapsing Pancreatitis (RP) 151
10.1.1 Neoplastic Causes of RP 152
10.1.1.1 Adenocarcinoma of the Papilla 152
10.1.1.2 Neuroendocrine Tumors 152
10.1.1.3 Mesenchymal Tumors 152
10.1.2 RP Due to Congenital Malformation 152
10.1.2.1 Pancreas Divisum 152
10.1.2.2 Annular Pancreas 152
10.1.2.3 Extraluminal Duodenal Diverticulum 152
10.1.2.4 Intraluminal Duodenal Diverticulum 154
10.1.2.5 Duodenal Duplication 154
10.1.2.6 Choledochal Cyst-Choledochocele 154
10.2 Chronic Pancreatitis (CP): Early Phase 154
10.3 Chronic Pancreatitis (CP): Advanced Phase 154
10.3.1 Obstructive Chronic Pancreatitis (OCP) 156
10.3.1.1 CT Characterisation of OCP 156
10.3.1.1.1 Parenchyma 156
10.3.1.1.2 Ducts 156
10.3.1.2 CT Diagnosis of Causes of OCP 158
10.3.1.2.1 Scarring from Severe Acute Pancreatitis (SAP) 158
10.3.1.2.2 Chronic Infl ammatory Stenosis of the Papilla 158
10.3.1.2.3 Duodenal Dystrophy 158
10.3.1.2.4 Congenital Lesions 162
10.3.1.2.5 Slow-growing Tumors 162
10.3.1.3 CT Differential Diagnosis: OCP vs Pancreatic Tumors 165
10.3.1.3.1 CT Differential Diagnosis: OCP vs IPMT 165
10.3.1.3.2 CT Differential Diagnosis: OCP Secondary to Solid Duodenal Dystrophy (SDD) vs Ductal Adenocarcinoma of the Head of the Pancreas 166
10.3.1.3.3 CT Differential Diagnosis: OCP Associated with Inverse Pancreas Divisum vs Neuroendocrine Tumors 166
10.3.2 Non-obstructive or Primitive Chronic Pancreatitis (PCP) 166
10.3.2.1 CT Identification of Hereditary PCP Secondary to Genetic Mutations 166
10.3.2.1.1 Ductal Structure 166
10.3.2.1.2 Parenchyma 170
10.3.2.2 CT Identification of Autoimmune PCP 170
10.3.2.2.1 Diffuse Form 170
10.3.2.2.2 Focal Form 173
10.3.2.3 CT Identification of PCP Associated with Toxic and Metabolic Factors 173
10.3.2.4 CT Differential Diagnosis: PCP vs Pancreatic Tumors 178
10.3.2.4.1 CT Differential Diagnosis: Autoimmune Focal PCP vs Ductal Adenocarcinoma 178
10.3.2.4.2 CT Differential Diagnosis: Diffuse Autoimmune PCP vs Lymphoma 178
10.3.2.4.3 CT Differential Diagnosis: Hereditary PCP from Genetic Mutations vs IPMT 178
10.3.2.4.4 CT Identification of Ductal Adenocarcinoma in Pre-existing CP 181
10.4 Conclusions 182
References 182
11 The Role of MR Imaging in Chronic Pancreatitis 185
11.1 Introduction 185
11.2 Magnetic Resonance: Examination Technique 186
11.2.1 Imaging of the Pancreatic Parenchyma 186
11.2.2 Imaging of the Ducts 188
11.2.3 Secretin-Enhanced Magnetic Resonance Cholangiopancreatography 189
11.3 Magnetic Resonance: Imaging Findings 192
11.3.1 Diagnosis 192
11.3.1.1 Early Chronic Pancreatitis 192
11.3.1.2 Advanced Chronic Pancreatitis 194
11.3.1.3 Autoimmune Pancreatitis 197
11.3.1.4 Paraduodenal Pancreatitis 197
11.3.2 Complication Assessment 199
11.3.3 Differentiation Between Carcinoma and Focal Infl ammatory Masses 200
11.3.4 Road Map for Treatment Planning and Follow-Up 203
11.4 Work in Progress: Diffusion-Weighted Imaging 204
11.4.1 Differential Diagnosis Between Mass-Forming Pancreatitis and Pancreatic Carcinoma 205
11.4.2 Exocrine Function Assessment 205
11.4.3 Monitoring ofAutoimmune Pancreatitis Treatment 205
11.5 Appendix 206
References 207
12 The Role of Endoscopic Retrograde Cholangiopancreatography (ERCP) 210
12.1 Introduction 210
12.2 Technical Principles of ERCP 211
12.2.1 Technical Success 212
12.2.2 Complications 213
12.3 ERCP for the Diagnosis of CP 216
12.3.1 Indications for Diagnostic ERCP 216
12.3.1.1 Diagnosis of Early CP 217
12.3.1.2 ERCP for CP Severity Assessment 219
12.3.1.3 ERCP for Complications Assessment 219
12.3.2 New Diagnostic Applications of ERCP 219
12.3.2.1 ERCP Tissue Sampling 219
12.3.2.2 Intraductal Optical Coherence Tomography 220
12.4 ERCP for the Treatment of CP 220
12.4.1 Pancreatic Ductal Stones 220
12.4.1.1 Selection of Patients 220
12.4.1.2 Pre-Procedural Evaluation 221
12.4.1.3 Techniques and Timing of ERCP 221
12.4.1.4 Results 221
12.4.2 Pancreatic Ductal Strictures 222
12.4.2.1 Selection of Patients 223
12.4.2.2 Techniques of Pancreatic Ductal Stenting 223
12.4.2.3 Results of Pancreatic Ductal Stenting 224
12.4.2.4 Timing of ERCP for Stent Exchange 224
12.4.2.5 Timing of ERCP for Stent Removal 225
12.4.2.6 Endoscopy or Surgery as the Best First-line Treatment for Symptomatic CP? 225
12.5 Conclusions 226
References 226
Complications of Acute and Chronic Pancreatitis 229
13 Pathology of Chronic Pancreatitis 230
13.1 Introduction 230
13.2 Alcoholic Chronic Pancreatitis 231
13.2.1 Macroscopy 231
13.2.2 Microscopy 231
13.2.3 Pathogenesis 235
13.3 Hereditary Pancreatitis 236
13.3.1 Pathology 237
13.4 Autoimmune Pancreatitis 239
13.4.1 Macroscopy 241
13.4.2 Microscopy 241
13.4.3 Extrapancreatic Involvement 244
13.4.4 Relationship to Inflammatory Pseudotumor 245
13.4.5 Differential Diagnosis 245
13.5 Paraduodenal Pancreatitis and Cysts of the Duodenal Wall 246
13.5.1 Macroscopy 247
13.5.2 Microscopy 247
13.5.3 Differential Diagnosis 249
13.6 Obstructive Chronic Pancreatitis 249
13.7 Idiopathic Chronic Pancreatitis 250
13.8 Metabolic Chronic Pancreatitis 251
13.9 Tropical Chronic Pancreatitis 251
13.10 Pancreatic Fibrosis Not Associated with Symptoms of Chronic Pancreatitis 251
13.11 Complications of Chronic Pancreatitis 251
13.11.1 Biliary Stricture 251
13.11.2 Duodenal Stenosis 252
13.11.3 Pseudocysts 252
13.11.4 Retention Cysts 252
13.11.5 Internal Pancreatic Fistulas 253
13.11.6 Splenic Vein Thrombosis 253
13.11.7 Concomitant Pancreatic Cancer 253
References 253
14 Clinical Aspect of Complications: Features and Prognoses 259
14.1 Introduction 259
14.2 Acute Pancreatitis 259
14.3 Complications 259
14.3.1 Systemic Complications: Multi-organ Failure 259
14.3.2 Local Complications 260
14.3.2.1 Pancreatic Necrosis 260
14.3.2.2 Fluid Collections 260
14.3.2.3 Pseudocyst 261
14.3.2.4 Infected Necrosis 261
14.3.2.5 Abscess 262
14.3.2.6 Fistulas 262
14.3.2.7 Fibrosis 262
14.4 Chronic Pancreatitis 262
14.4.1 Malabsorption 263
14.4.2 Diabetes 263
14.4.3 Ductal Carcinoma 263
14.5 Local Complications 263
References 264
15 Imaging of Pancreatic Pseudocyst 266
15.1 Definition 266
15.1.1 Epidemiology 266
15.1.2 Pathogenesis 267
15.2 Pathological Findings 271
15.2.1 Macroscopic Findings 271
15.2.2 Microscopic Findings 273
15.3 Role of Imaging 273
15.4 US Imaging 273
15.5 CT Imaging 273
15.6 MR Imaging 275
15.7 Endoscopic Ultrasound Imaging (EUS) 278
15.8 Differential Diagnosis 278
15.8.1 Cystic Dystrophy of Duodenum 279
15.8.2 Mucinous Cystic Pancreatic Tumor 280
15.8.3 Serous Cystadenoma 280
15.8.4 Intraductal Papillary Mucinous Tumors of the Collateral Ducts (IPMT II Type) 281
15.8.5 Solid and Papillary Tumor 282
15.8.6 Other Cystic Tumors 282
15.9 Role of Needle-Aspiration Biopsy 283
15.10 Pre-operative Assessment 283
15.11 Pseudocyst Evolution 283
15.12 Complications 284
15.12.1 Infection and Pancreatic Abscess 284
15.12.2 Vascular Complications 285
15.12.3 Jaundice 285
15.12.4 Compression on Gastro-intestinal and Urinary Tracts 285
15.12.5 Rupture and Fistulas 286
15.12.6 Pleural Eff usion 289
References 289
16 Imaging of Biliary and Vascular Complications 291
16.1 Introduction 291
16.2 Vascular Complications 291
16.2.1 Arterial Complications 291
16.2.1.1 Arterial Disruption 292
16.2.1.2 Pseudoaneurysm and Bleeding Pseudocyst 293
16.2.1.3 Haemosuccus Pancreaticus 296
16.2.1.4 Acute Bleeding in Acute Pancreatitis 296
16.2.2 Venous Complications 298
16.2.2.1 Venous Thrombosis 298
16.2.2.2 Pancreatic Duct/Portal Vein Fistula 298
16.2.2.3 Thrombophlebitis of the Peripancreatic Tributaries of the Portal Vein 298
16.3 Biliary Complications 298
16.3.1 Biliary Tract Obstruction 302
16.3.2 Pancreaticobiliary Fistula 302
References 305
17 Imaging of Local Extension and Fistulas 307
17.1 Introduction 307
17.2 Pancreatic Complications 307
17.2.1 Pancreatic Necrosis 307
17.2.2 Collections 308
17.2.2.1 Sterile Collections 308
17.2.2.2 Infected Necrosis 308
17.2.2.3 Imaging Findings 308
17.2.3 Pancreatic Abscess 312
17.2.4 Hemorrhage 312
17.2.5 Fistulas 313
17.2.5.1 Internal Fistulas 314
17.2.5.1.1 Pancreatico-enteric Fistulas 314
17.2.5.1.2 Pancreatico-biliary Fistulas 314
17.2.5.1.3 Pancreatico-venous Fistulas 315
17.2.5.1.4 Pancreatico-pleural Fistulas 316
17.2.5.2 External Fistulas 317
17.2.5.2.1 Post-Traumatic Fistulas 317
17.2.5.2.2 Post-Surgical Fistulas 317
17.3 Extrapancreatic Complications 317
17.3.1 Intestinal Stenosis 317
17.3.2 Peptic Ulcer 320
17.3.3 Ascites 320
17.3.4 Splenic Involvement 321
17.4 Conclusions 321
References 322
18 Chronic Pancreatitis vs Pancreatic Tumors 325
18.1 Introduction 325
18.2 Focal Chronic Pancreatitis 325
18.2.1 Introduction 325
18.2.2 Mass Forming Pancreatitis 326
18.2.2.1 Introduction 326
18.2.2.2 Differential Diagnosis at Imaging 326
18.2.2.3 Role of US/EUS 327
18.2.2.4 Role of CT 333
18.2.2.5 Role of MR 334
18.2.3 Autoimmune Chronic Pancreatitis 334
18.2.3.1 Introduction 334
18.2.3.2 Differential Diagnosis at Imaging 340
18.2.3.3 Role of US 342
18.2.3.4 Role of CT 342
18.2.3.5 Role of MR 342
18.2.3.6 Role of ERCP 342
18.2.4 Cystic Duodenal Dystrophy (Solid Variant) 342
18.2.4.1 Introduction 342
18.2.4.2 Differential Diagnosis at Imaging 343
18.2.4.3 Role of US and EUS 349
18.2.4.4 Role of CT 349
18.2.4.5 Role of MR 349
18.2.5 Role of Nuclear Medicine 350
18.3 Diffuse Dilation of the Main Pancreatic Duct 353
18.3.1 Introduction 353
18.3.2 OCP vs Ductal or Ampullary Adenocarcinoma 353
18.3.3 CP vs IPMT of the Main Duct 353
18.3.3.1 Role of US/EUS 357
18.3.3.2 Role of CT and MR 359
18.3.3.3 Role of Pancreatoscopy 361
References 361
19 The Role of Endoscopy in Acute and Chronic Pancreatitis 366
19.1 General Issues 366
19.2 Biliary Obstruction in Acute and Chronic Pancreatitis 367
19.3 Pancreatic Pseudocysts 368
19.3.1 Endoscopic Transmural Drainage – Candidates 369
19.3.2 Endoscopic Pseudocyst Drainage – Technique 369
19.3.3 Transpapillary Drainage of Pseudocysts 372
19.3.4 Outcomes of Endoscopic Drainage 372
19.3.5 Complications of Endoscopic Pseudocyst Drainage 373
19.3.6 Recurrence After Endoscopic Pseudocyst Drainage 374
19.4 Endoscopic Management of Other Pancreatic Fluid Collections 374
19.4.1 Endoscopic Management of Pancreatic Duct Leaks 375
19.5 Conclusions 376
References 376
20 Surgical and Interventional Perspective in Chronic Pancreatitis 378
20.1 Introduction and Therapeutic Indications 378
20.1.1 Signs and Symptoms 378
20.1.2 Development of the Disease 379
20.1.3 Morphological Aspects Evaluated with Imaging 379
20.2 Clinico-morphologic Correlation and Therapeutic Choices 379
20.2.1 Pain 379
20.2.1.1 Pain Associated with Uniform Dilatation of the Wirsung Duct 380
20.2.1.2 Pain Associated with “Chain-of-Lake” Dilatation of the Wirsung Duct 380
20.2.1.3 Pain Asscociated with Segmental Dilatation of the Wirsung Duct 381
20.2.1.4 Pain and Groove Pancreatits 381
20.2.1.5 Pain and Suspected Tumor 381
20.2.2 Pseudocysts 382
20.2.3 Biliary Obstruction 382
20.2.4 Duodenal Obstruction 383
20.3 Conclusions 383
References 384
Subject Index 386
List of Contributors 394