Maconi / Bianchi Porro Ultrasound of the Gastrointestinal Tract
1. Auflage 2007
ISBN: 978-3-540-49841-4
Verlag: Springer
Format: PDF
Kopierschutz: 1 - PDF Watermark
E-Book, Englisch, 227 Seiten, Web PDF
Reihe: Diagnostic Imaging
ISBN: 978-3-540-49841-4
Verlag: Springer
Format: PDF
Kopierschutz: 1 - PDF Watermark
Transabdominal ultrasound is accepted in clinical practice as a primary imaging procedure in the diagnostic work-up and follow-up of a number of disorders of the gastrointestinal tract. This book provides a comprehensive overview of the use of ultrasound in the imaging of acute and chronic inflammatory conditions, as well as of neoplastic and infectious diseases of the gastrointestinal tract. The book explains specific ultrasound features of gastrointestinal disorders, and appraises the value and limits of ultrasound. Each chapter offers a description of findings obtained with ultrasound, and includes consideration of alternative diagnostic imaging methods for comparative purposes. The discussion extends to relevant technical developments and applications, such as functional and 3D ultrasound, contrast agents and operative ultrasound. The contributors are considered authorities in their specific fields. The book is up-to-date with the latest innovations, and includes many high-quality illustrations.
Zielgruppe
Professional/practitioner
Weitere Infos & Material
Acute Abdomen.- Acute Appendicitis and Appendiceal Mucocele.- Mesenteric Lymphadenopathy.- Acute Colonic Diverticulitis and Diverticulosis.- Intestinal Obstruction.- Abdominal Hernias, Volvulus and Intussusception.- Ischemic Colitis.- Chronic Inflammatory Bowel Diseases.- Crohn’s Disease.- Ulcerative Colitis.- Malabsorption.- Coeliac Disease.- Lymphangiectasia, Whipple’s Disease and Eosinophilic Enteritis.- Infections.- Infectious Enteritis.- Intestinal Tuberculosis.- Pseudomembranous Colitis.- Amoebic, Ascariasis and Other Parasitic and Infectious Enteritis.- Neoplasm.- Colorectal Cancer.- Gastric Cancer.- Gastrointestinal Lymphoma.- Peritoneal Metastasis.- Carcinoid and Submucosal Tumors.- Procedures and Technical Developments.- Intravenous Contrast-Enhanced Bowel Ultrasound.- Oral Contrast-Enhanced Bowel Ultrasound.- Functional Ultrasound of the Gastrointestinal Tract.- Three-Dimensional Ultrasound of the Gastrointestinal Tract.- Percutaneous Gastrointestinal Biopsy.
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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.
