GI Tract Imaging (PDF)

FRD40721 - Radiography & Medical Imaging Science ( Ultrasound Imaging ) Lecture 12 Gastro-Intestinal Tract Imaging Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Readings 1. Rumack, CM Wilson, SR Charboneau, JW 2011, Diagnostic...

FRD40721 - Radiography & Medical Imaging Science ( Ultrasound Imaging ) Lecture 12 Gastro-Intestinal Tract Imaging Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Readings 1. Rumack, CM Wilson, SR Charboneau, JW 2011, Diagnostic Ultrasound Vol.1, 4th Ed. Mosby, St. Louis 2. Bates, JA 2011, Abdominal Ultrasound: How, Why and When, 3rd Ed. Churchill Livingstone, Edinburgh. 3. Zelesco, M. 2001, “Ultrasound of the Veriform Appendix”, Sound Effects, June pp.32-37. Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Anatomy Alimentary canal – Mouth – Pharynx – Oesophagus – Stomach – Small intestine – Large intestine Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Anatomy: Stomach • The stomach is a muscular organ located on the left side of the upper abdomen. • Receives food from the esophagus. • Secretes acid and enzymes that digest food. • Ridges of muscle tissue called rugae line the stomach. • The pyloric sphincter is a muscular valve that opens to allow food to pass from the stomach to the small intestine. Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Anatomy: Stomach Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Anatomy: Small Bowel • The small intestine (small bowel) lies between the stomach and the large intestine (large bowel) • Consist of the duodenum, jejunum, and ileum. • Its lumen diameter is smaller than that of the large intestine, but longer length than the large intestine. • The duodenum continues into the jejunum at the duodenojejunal junction or flexure. • Absorb most of the nutrients from what we eat and drink. Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Anatomy: Small Bowel Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Anatomy: Large Bowel • Large intestine includes the cecum along with appendix and the colon. • Also includes the rectum and anal canal. • Its lumen (diameter) is larger than the small intestine. • Absorbs water from wastes, creating stool. • As stool enters the rectum, nerves there create the urge to defecate. Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Anatomy: Large Bowel Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Anatomy - The Gut • Continuous hollow tube (lumen) • 4 layer walls (inner to outer): 1. Mucosa 2. Submucosa 3. Muscularis propria 4. Serosa Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Anatomy - The Gut Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae US Equipment • Curvilinear : 5-2 MHz / overview • Linear: 7-4, 13-10, 9-4 MHz / focussed scanning Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Patient Preparation • Aimed at removing excess gas from stomach and bowel • Fasting: – 8 -12 hrs / or (6-8 hrs) – Up to 24 hrs beneficial Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Ultrasound Appearance • Look for the ‘Gut Signature’ • Compression - any area of interest; – Normal bowel easily compressed and soft under probe – Short focal zone for superficial structures – Slow graded pressure - more tolerance in areas of tenderness Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Anatomy - The ‘Gut Signature’  Up to 5 layers seen on US  Normal wall is uniform  Assess: • Content of lumen • Diameter of lumen • Peristalsis • Compressibility Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae The Gut Signature - 5 layers Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Anatomy - The ‘Gut Signature / 3 layers Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Stomach Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Pathology – Ultrasound – Used in conjunction with other modalities – Gas limiting factor Role of Ultrasound – Detect free fluid(e.g ruptured appendix) – Masses(cysts, tumours etc.,localise source) – Surrounding tissue(inflamed fat, reactive nodes) – Gut – Clinical interaction - pain on palpation Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Pathology • Neoplasms (new and abnormal growth of tissue in a part of the body) o Adenocarcinoma o Metastases • Inflammatory Bowel Disease o Crohn’s disease • Appendicitis • Obstruction Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Pathology Any variation from normal ‘gut signature’ or behaviour should be considered suspicious:  Non-compressible gut  Diffuse or focal wall thickening  Exophytic masses  Dilated lumen  Hyper / hypo peristalsis  Adjacent hyperechoic fat  lymphadenopathy Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Ultrasound Appearances of Pathology Rumack, CM Wilson, SR & Charboneau, JW 2011, Diagnostic Ultrasound Vol.1, 4th edn, Mosby Year Book, St. Louis Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Pathology - Neoplasm Intra mural lesions Exophytic lesions Lesions which destroy bowel wall Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Pathology - Neoplasm ADENOCARCINOMA – Most common GIT malignancy – Affects stomach and large bowel more often than small bowel – Colorectal Adenocarcinoma is common (3rd after Ca breast and lung) Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae ADENOCARCINOMA ULTRASOUND Appearance: – Large masses – Thickened gut wall with symmetric or asymmetric pattern – Target or pseudokidney sign – Usually hypoechoic Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Pathology: ADENOCARCINOMA Target Sign Rumack, CM Wilson, SR & Charboneau, JW 2011, Diagnostic Ultrasound Vol.1, 4th edn, Mosby Year Book, St. Louis Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae ADENOCARCINOMA Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae ADENOCARCINOMA Pseudokidney Sign Rumack, CM Wilson, SR & Charboneau, JW 2011, Diagnostic Ultrasound Vol.1, 4th edn, Mosby Year Book, St. Louis Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae ADENOCARCINOMA Pseudokidney Sign Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Pathology - Neoplasm Metastases – Breast, lung common primaries – Stomach, small bowel, colon involved – Large diffusely infiltrative mass with bright linear echoes representing gas(ringdown) – Particulate ascites associated with metastases Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Pathology - Neoplasm Metastases Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Pathology – Inflammatory Bowel Disease Crohn’s disease • Type of inflammatory bowel disease • Most commonly in ileum and colon • Affects all layers of wall; o Typically thick and rigid with secondary narrowing of lumen Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Crohn’s disease Note thickened muscularis layer of terminal ileum and increase in echogenicity, and increased vascularity. Loss of differentiation of bowel layers Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Pathology - Acute appendicitis – Inflammation of the appendix – Worm-like extension of caecum – Any age, more common in males – peak incidence 20-30ys Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Variations in position Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Pathology - Acute appendicitis Symptoms; – Abdominal pain – Vomiting, nausea, loss of appetitie – Fever – Increase WBC count Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Pathology - Acute appendicitis – Tenderness in inflamation area – Increasing pain with cough – Variable location Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Pathology - Acute appendicitis ULTRASOUND – Transverse plane for best view – Hyperechoic and hypoechoic concentric layers – If total diameter >6mm non compressible – Appendicolith – Increased echogenicity surrounding fat – Free fluid in pelvis Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Normal Appendix • Compressible and ≤ 6mm Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Pathology - Acute appendicitis Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Pathology - Acute appendicitis Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Appendicolith Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Pathology - Obstruction • Obstruction of the intestines prevents the normal movement of the products of digestion. • Ultrasound often not helpful / Usually CT • Most patients - gaseous distention • Accumulation of fluid/gas • Partial or complete Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Obstruction Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae QUESTIONS??? Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Quiz Questions The most common malignancy of the GIT is a) Lymphoma b) Metastases c) Crohn’s disease d) Adenocarcinoma Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae Quiz Questions What is meant by the term “gut signature” and how does it aid in diagnosing pathology of the bowel? ( 5 marks) Course: FRD3061 Medical Imaging Science and Methods 2Ultrasound 1 Lecture 7B: Gastro-Intestinal Tract fchs.ac.ae