Ultrasound of the Gastrointestinal Tract (eBook)

Dr. Giovanni Maconi Born in 1964. Graduated from Pavia University and received his Medical Degree in 1989. Specialized in Gastroenterology at the Catholic University of Rome in 1993. He joined the "L. Sacco University Hospital", Milan, in 1992. Since December 2002 he is lecturer in Gastroenterology at the University of Milan. Thanks to his extensive research activities, he was awarded at young clinician program at World Congress of Gastroenterology, Vienna, in 1998. Author and co-author of over 70 scientific papers, mostly on Ultrasound and Gastroenterology and particularly on the role of bowel ultrasound in chronic inflammatory bowel diseases. He sits on the Editorial Board of the Scandinavian Journal of Gastroenterology, the World Journal of gastroenterology Digestive and Liver Disease. Prof. Gabriele Bianchi Porro Born in Forli, Italy. Graduated from Milan University and received his Medical Degree in 1962. He joined the "L. Sacco University Hospital", Milan, in 1972 and after two years was appointed Head of the Gastroenterology Unit. At present he holds the Chair of Gastroenterology at the University of Milan. Author of over five hundred scientific papers, mostly on Gastroenterology, and more than 30 books. He is Editor in Chief of Digestive & Liver Disease, International Editor of the Scandinavian Journal of Gastroenterolog, and Associate Editor of Current Treatment Options in Gastroenterolgy. He sits on the Editorial Boards of the European Journal of Gastroenterology and Hepatology, the Journal of Internal Medicine, Drugs, Drug Investigation, Drugs and Ageing.

Foreword 5
Preface 7
Contents 9
Acute Abdomen 11
1 Acute Appendicitis and Appendiceal Mucocele 13
1.1 Introduction 13
1.2 Clinical Evaluation of Acute Appendicitis 13
1.3 Diagnostic Methods 13
1.4 Differential Diagnosis 17
1.5 Mucocele of the Appendix 19
1.6 Conclusion 19
References 19
2 Mesenteric Lymphadenopathy 21
2.1 Introduction 21
2.2 Normal Mesenteric Lymph Nodes 21
2.3 Neoplastic Conditions 22
2.4 Inflammatory Conditions 24
2.5 Infectious Conditions 26
2.6 Primary Mesenteric Lymphadenitis 27
3 Acute Colonic Diverticulitis and Diverticulosis 29
3.1 Introduction 29
3.2 Diverticulosis 29
3.3 Diverticulitis 31
3.4 Conclusion 34
References 35
4 Intestinal Obstruction 37
4.1 Introduction 37
4.2 Pathology of Bowel Obstruction 37
4.3 Small Bowel Obstruction 38
4.4 Colon Obstruction 42
4.5 Paralytic Ileus 42
References 44
5 Abdominal Hernias, Volvulus and Intussusception 45
5.1 Abdominal Hernias 45
5.2 Small Bowel Volvulus 54
5.3 Gastric Volvulus 56
5.4 Caecal Volvulus 57
5.5 Intussusception 58
References 63
6 Ischemic Colitis 65
6.1 Introduction 65
6.2 Imaging Findings 65
6.3 Sonographic Findings 66
6.4 Computed Tomography Findings 66
References 68
Chronic Inflammatory Bowel Diseases 70
7 Crohn’s Disease 71
7.1 Introduction 71
7.2 Pathological Features 71
7.3 Ultrasonographic Features of Bowel Walls 72
7.4 Abdominal Complications of Crohn’s Disease 76
8 Ulcerative Colitis 83
8.1 Introduction 83
8.2 Clinical and Pathological Features 83
8.3 Ultrasonographic Features of Bowel Walls 85
8.4 Detection and Determination of Extension 88
8.5 Assessment of Disease Activity 88
8.6 Toxic Megacolon 89
8.7 Differential Diagnosis Between Ulcerative Colitis, Crohn’s Disease and Other In. ammatory Diseases 89
References 90
Malabsorption 93
9 Coeliac Disease 95
9.1 Introduction 95
9.2 Abdominal Ultrasound in the Diagnosis of Coeliac Disease 95
9.3 Splanchnic Circulation in Coeliac Disease 99
9.4 Role of Ultrasonography in Diagnosing the Complications of Coeliac Disease 99
9.5 Gallbladder Motility and Gastric Emptying in Coeliac Disease: Ultrasonographic Studies 100
References 101
10 Lymphangiectasia, Whipple’s Disease and Eosinophilic Enteritis 103
10.1 Primary Intestinal Lymphangiectasia 103
10.2 Whipple’s Disease 104
10.3 Ultrasonography in the Diagnosis and Follow-Up of Eosinophilic Enteritis 105
References 106
Infections 109
11 Infectious Enteritis 111
11.1 Clinical Features 111
11.2 Infectious Enteritis and Colitis 112
11.3 Infectious Bacterial Ileocecitis 114
11.4 Neutropenic Enterocolitis 116
References 117
12 Intestinal Tuberculosis 119
12.1 Introduction 119
12.2 Pathology 119
12.3 Sonographic Findings of Intestinal Tuberculosis 119
12.4 Sonographic Findings of Tuberculous Peritonitis 122
12.5 Differential Diagnosis 123
References 124
13 Pseudomembranous Colitis 125
13.1 Introduction 125
13.2 Microbiology 126
13.3 Clinical Manifestations 126
13.4 Endoscopy 126
13.5 Imaging Study 126
References 129
14 Amoebic, Ascariasis and Other Parasitic and Infectious Enteritis 131
14.1 Amoebiasis 131
14.2 Ascariasis 132
14.3 Trichuriasis 134
14.4 Oesophagostomiasis 134
References 135
Neoplasm 137
15 Colorectal Cancer 139
15.1 Introduction 139
15.2 Pathology 139
15.3 Transabdominal Sonographic Technique 140
15.4 Transabdominal Sonographic Findings of Colon Cancer 140
15.5 Transrectal Sonography 141
References 144
16 Gastric Cancer 145
16.1 Introduction 145
16.2 Sonographic Assessment of the Gastric Wall 145
16.3 Sonographic Features of Gastric Cancer 146
16.4 Staging of Gastric Cancer 150
16.5 Conclusion 151
References 152
17 Gastrointestinal Lymphoma 153
17.1 Introduction 153
17.2 Endoscopic Ultrasound 153
17.3 Transabdominal Ultrasound 158
18 Peritoneal Metastasis 161
18.1 Introduction 161
18.2 Ultrasonographic Findings 161
18.3 Differential Diagnosis and Role of Ultrasound-Guided Biopsy of Peritoneal Masses 166
References 167
19 Carcinoid and Submucosal Tumors 169
19.1 Introduction 169
19.2 Preparations for Sonographic Assessment of Submucosal Tumors 169
19.3 Carcinoid Tumor 169
19.4 Submucosal Tumor 171
19.5 Conclusion 175
References 175
Procedures and Technical Developments 177
20 Intravenous Contrast-Enhanced Bowel Ultrasound 179
20.1 Introduction 179
20.2 Bowel Sonography (B-Mode, Doppler and Power Doppler Sonography) 179
20.3 Intravenous Contrast Agents 180
20.4 Contrast Harmonic Imaging 183
20.5 Instrumentation Technology 184
20.6 Intravenous Contrast-Enhanced Bowel Sonography 184
20.7 Future Prospects 188
References 188
21 Oral Contrast-Enhanced Bowel Ultrasound 191
21.1 Introduction 191
21.2 Hydrosonography of the Stomach 191
21.3 Small Intestine Contrast Ultrasonography 192
21.4 Hydrocolonic Sonography 196
References 196
22 Functional Ultrasound of the Gastrointestinal Tract 199
22.1 Introduction 199
22.2 Distal Stomach 200
22.3 Gastric Emptying 200
22.4 Proximal Stomach and Gastric Accommodation 201
22.5 Antral Peristalsis 202
22.6 Flow of Luminal Contents 203
22.7 Gastroesophageal Re. ux Disease 204
22.8 Gallbladder 205
22.9 Ultrasound as a Clinical Tool to Evaluate Patients with Functional GI Disorders 205
References 206
23 Three-Dimensional Ultrasound of the Gastrointestinal Tract 209
23.1 Introduction 209
23.2 Formation of 3D Ultrasonographic Images 209
23.3 Three-Dimensional Ultrasonography of the Stomach 212
23.4 Three-Dimensional Endoscopic Ultrasonography 215
23.5 Three-Dimensional Ultrasonography of the Rectum 217
23.6 Conclusion 218
References 218
24 Percutaneous Gastrointestinal Biopsy 223
24.1 Introduction 223
24.2 Indications and Contraindications 224
24.3 Technique 224
24.4 Results 226
References 228
Subject Index 231

Mesenteric Lymphadenopathy (p 11)

Giovanni Maconi, Elisa Radice, and Gabriele Bianchi Porro
2.1 Introduction

Wíth the increasing use of abdominal and bowel ultrasound in the screening and follow-up of bowel diseases, enlargement of the regional mesenteric lymph nodes have become a fairly common clinical finding, particularly in children and young adults. Therefore, since lymphadenopathy may often be an incidental finding in patients being examined for various reasons, the sonographer (and the physician) must decide whether it is a normal finding or a sign of a patient’s condition requiring further study. Indeed, mesenteric lymphadenopathy may be a manifestation of various disorders (Table 2.1).

2.2 Normal Mesenteric Lymph Nodes

Regional mesenteric lymph nodes are usually detected as the result of a symptom-directed diagnostic work-up, by a variety of imaging techniques, including ultrasound and colour Doppler ultrasonography, computed tomography (CT) and magnetic resonance imaging (MRI).

When they are found, the main goal of the diagnostic technique is to suggest whether it is a normal finding or the sign of a past or ongoing abdominal disease, and in this context, to differentiate its benign from malignant nature. The ultrasonographic criteria of the enlargement of mesenteric lymph nodes has been variably defined as the detection of nodes larger than 4 mm in the short axis (Sivit et al. 1993) and larger than 10 mm in the long axis (Watanabe et al. 1997).

This sonographic definition is in agreement with that of a study based on CT studies in an adult population where mesenteric lymphadenitis has been defined as three or more lymph nodes, each 5 mm or greater 5 mm in the short axis (Macari et al. 2002).

However, this size might not be a reliable normal cut-off value in children where it is much more controversial. A recent study showed that using a threshold of short-axis 5 mm for enlarged mesenteric lymph nodes might yield an unacceptably high percentage (54%) of false-positive results and that a better defi - nition of enlarged mesenteric lymph node would be a short axis of >,8 mm, which yielded only a 5% falsepositive rate (Karmazyn et al. 2005).

Therefore, the sonographic detection of oval, elongated, U-shaped lymph nodes with a short-axis diameter up to 4 mm in adults and 8 mm in children, should be considered a normal finding and should not be misdiagnosed as an early manifestation of a lympho-proliferative disorder.

The size of the nodes alone does not always re. ect underlying disease. The number and distribution of lymph nodes is also important. Normal mesenteric lymph nodes may be routinely identified at the mesenteric root and throughout the mesentery, in particular in right iliaca fossa in children (Karmazyn et al. 2005) and at the mesenteric root in adults (Lucey et al. 2005) (Fig. 2.1).

Size, site and number of lymphadenopathy detected by abdominal ultrasound may therefore help in suggesting their nature, or at least in differentiating among their main causes, which may be neoplastic, infectious or inflammatory.