USG GI tract of dog prepare by dr.Pravin Chaudhary.pptx

Ultrasonograpy future of gastrointestinal tract in dog

1. Ultrasonograpy of the Gastrointestinal Tract in dog Name : Chaudhary Pravin Bhai..N Group No: 01 Reg.no:3040419009 College of veterinary science and animal husbandry., Navsari

2. Specific indications for gastrointestinal ultrasonography Chronic vomiting and diarrhoea
Palpable abdominal masses or thickening of gastrointestinal structures
Abdominal pain
Weight loss and/or anorexia
Suspicion of ingested foreign bodies Investigating possible hernias neoplasia

3. Key points: One of the major limiting factors when attempting to image the Gl tract is the presence of gas within the lumen. Reverberation artefact caused by gas prevents visualisation of the far field, often preventing complete evaluation of structures.

4. Preparing the patient by withholding food for 12 to 24 hours prior to examination is recommended. A high frequency linear or micro-convex transducer (7mHz or higher) should be used to enable assessment of w all layering .

5. Dorsal, left or right lateral recumbency can be utilised and different advantages. Dorsal recumbency is likely to allow complete visualisation of the gastrointestinal tract, lateral recumbency (left or right) will assist with redistribution of luminal gas or fluid, thus allowing more compelet visualisation of individual sections of the Gl tract

6. This ventrodorsal abdominal radiograph has been annotated to give a schematic representation of the position and course of parts of the Gl tract in a dog. In cats, the stomach is orientated more obliquely, and the pylorus and duodenum are positioned closer to the midline.

7. Normal Appearance of GI tract Wall lay ring of the gastrointestinal tract can be divided in to 5 distinct layers: Lumen : hyperechoic Mucosa : hypoechoic Submucosa : hyperechoic Muscularis : hypoechoic Serosa :Thin hyperechoic layer Gl segment Canine (mm) Wall thickness Stomach 2.0-5.0 Duodenum 2.9-5.7 Jejunum 2.2-4.7 Colon 1.0-2.6

8. All sections of the Gl tract share a common layered ultrasonographic appearance However, the overall and relative thickness of parts of the Gl tract layers varies with different sections of the Gl tract.

9. STOMACH: From the xiphoid position, slide the transducer caudally so that the stomach is in short axis (in transverse section) . When the transducer is swept toward the right side , the pyloroduodenal junction is visualized as the thickened area of the muscularis between the pylorus and proximal duodenum.

10. Observing peristaltic contractio ns can be used to assess motility; these average at around five contractions per minute. Stomach Wall : The appearance of the stomach is variable depending on luminal contents. Collapse of the stomach walls in the image on the left prevents easy identification of the stomach lumen. Artefact caused by the ingesta and gas in the image on the right prevents visualisation o f the far wall of the stomach .

11. The stomach has a variable appearance, depending upon luminal content Appearance of a wagon wheel.

12. Duodenum The canine duodenum is located running in a cranio -caudal direction along the right lateral body wall, following a superficial and more linear path than the jejunum

13. Transverse image of the proximal duodenum at the level of the duodenal papilla. Ultrasound image of the longitudinal view of the normal canine descending duodenum Bile ducts

14. Longitudinal axis view of the proximal descending duodenum of a normal dog. The focal indentation (white arrow) in the duodenal mucosa (rectangular or square hyperechoic area) is a “ pseudo ulcer ” due to a Peyer’s patch; this is a normal finding in the dog. Pseudo ulcer”

15. Jejunum Jejunal loops can be visualised throughout the abdomen. Motility ranges from 1-3 peristaltic contractions per minute. Ileum: The ileum is most readily identified using a right lateral approach . The prominent submucosa and contracted state give the lumen a star shape or rosetted , sphincter-like appearance

16. Lumen a star shape or rosetted ,

17. Colon: In comparison to the more proximal sections of Gl tract, the colon has a much thinner total wall thickness, with layering which is more difficult to evaluate without a high frequency probe . Intraluminal gas and faecal contents commonly cause a distal acoustic shadowing artefact, which obscures the far wall.

18. Ultrasonographic appearance of gastrointestinal pathology. Following factors should be evaluated : Total wall thicknes s or changes in relative wall layer thickness Alteration in the relative echogenicit y of the layers Alteration in the pattern or distinction of wall layering Alteration in motility : hypermotility , spasmodic motility or intestinal ileus Identification of luminal contents

19. Assessment of associated anatomy including lymphadenopathy, echogenic changes to the surrounding mesentery and presence of abdominal free fluid should also be performed.

20. Gastric lymphoma intramural mass with associated loss of layering, thickened stomach wall and relative change in echogenicity

21. Gastric Foreign Body Foreign body in present within the gastric lumen (arrow) Acoustic shadow artefact

22. corrugation This image shows a section of jejunum (arrow). The intestinal wall has an undulating pattern typical of corrugation.

23. Intussusception This image shows a transverse plane image of an intussusception. Here, a multi-layered ‘target’ or ‘ bullseye ’ pattern can be seen, caused by one section of small intestine invaginating within itself.

24. Foreign body in intestine