{"id":14336,"date":"2018-03-18T18:02:30","date_gmt":"2018-03-18T18:02:30","guid":{"rendered":"http:\/\/phosdev.com\/todaysveterinarypractice\/?p=14336"},"modified":"2022-03-31T14:12:07","modified_gmt":"2022-03-31T14:12:07","slug":"ultrasonography-of-the-gastrointestinal-tract-ileum-cecum-colon","status":"publish","type":"post","link":"https:\/\/navc.sitepreview.app\/todaysveterinarypractice.com\/radiology-imaging\/ultrasonography-of-the-gastrointestinal-tract-ileum-cecum-colon\/","title":{"rendered":"Ultrasonography of the Gastrointestinal Tract: Ileum, Cecum, Colon"},"content":{"rendered":"
Welcome to this series of articles on small animal abdominal ultrasonography. The initial articles provided an overview of basic ultrasonography principles and a discussion about how to perform a systematic scan of the abdomen. The rest of the series discusses ultrasound evaluation of specific abdominal organs\/systems.<\/div>\n
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Localization and Scanning Technique<\/h2>\n

Dogs and cats are positioned in dorsal or lateral recumbency for scanning of the gastrointestinal tract. Longitudinal axis and transverse axis views of the different segments of the gastrointestinal tract are necessary for a complete examination.<\/p>\n

Maintain a consistent sequence when evaluating the complete gastrointestinal tract; preferably, in the following order: stomach, duodenum, jejunum (see \u201cUltrasonography of the Gastrointestinal Tract: Stomach, Duodenum, and Jejunum<\/a>\u201d [January\/February 2018]), ileum, (cecum), ileocecocolic (cat) or ileocolic (dog) junction, cecum, and parts of the colon (ascending, transverse, descending).<\/p>\n

Ileum<\/h3>\n

The normal canine and feline ileum is short and is typically located in the right cranial to mid-quadrant of the abdominal cavity, medial to the right kidney. The ileum can be found using the transverse colon or ileo(ceco)colic junction as a guide.<\/p>\n

The transverse colon, which is immediately caudal to the gastric body, is followed to the right of midline to the level of the ascending colon; continuing in an oral direction, bypass the ileo(ceco)colic junction to image the ileum.<\/p>\n

The ileum is more difficult to identify in dogs than cats due to interposition of the normal gas filled cecum.<\/p>\n

Ileocecocolic and Ileocolic Junctions<\/h3>\n

The ileocecocolic junction (cats) or ileocolic junction (dogs) is usually located within the right cranial abdominal quadrant medial to the right kidney (FIGURES 1 AND 2<\/strong>).<\/p>\n

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FIGURE 1. Short axis view of the transverse colon in a dog; the transverse colon is located caudal to the liver and stomach. On this sagittal image of the abdomen (cranial is to the left), note the thin walled, gas filled transverse colon with dirty acoustic shadowing.<\/p><\/div>\n

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FIGURE 2. Short axis view of the caudal aspect of the descending colon in a dog. Note the thin walled (white arrowhead), gas filled descending colon with dirty acoustic shadowing. The urinary bladder is used as a landmark to find the descending colon in the far field of the image.<\/p><\/div>\n

Cecum<\/h3>\n

The canine and feline cecum is a blind sac that is medial to the descending duodenum and can usually be found caudolateral to the ileo(ceco)colic junction. Due to the superimposition of gas filled intestinal segments, the cecum is not always identifiable.<\/p>\n

Colon<\/h3>\n

All parts of the colon are fully evaluated by beginning at the level of the ileocecocolic junction in the cat and ileocolic junction in the dog and sweeping the transducer cranially along the ascending colon. The ascending colon is a short segment of large intestine in the right cranial abdominal quadrant.<\/p>\n

Continue leftwards along the transverse colon. The transverse colon spans the right to left cranial abdomen and can readily be identified using the stomach as a landmark; it is located immediately caudal to the greater curvature of the stomach (FIGURE 1<\/strong>). Finish scanning the colon by continuing caudally along the descending colon.<\/p>\n

Using the urinary bladder as a landmark to identify the descending colon (FIGURE 2<\/strong>), a reversed approach (descending colon, transverse colon, and then ascending colon) can also be used. The descending colon, usually containing gas or feces, is located immediately dorsal to the urinary bladder, within the far field of the image.<\/p>\n

BOX 1 Criteria for Assessing the Ileum and Colon Include:<\/div>
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