Term
| Describe the size of the large bowel. |
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Definition
-lager than the small bowel
-Dogs: should be <1-1.5X the length of L7
-Cats: max is L5 diameter |
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Term
| What size bowel counts as megacolon in a cat? |
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Definition
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Term
| How thick is the wall of the large bowel? |
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Definition
| -2mm (half that of the small bowel) |
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Term
| Describe the shape of the colon. |
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Definition
| -appears as a tubular question mark or sheperd hook on VD view |
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Term
| Describe the shape of the cecum in the dog and cat. |
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Definition
-Dogs: large, coiled, or corkscrew cecum
-Cats: small, comma-shaped cecum |
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Term
| Describe the normal location of the cecum. |
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Definition
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Term
| Describe the normal location of ascending colon. |
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Definition
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Term
| Describe the normal locaiton of the descending colon. |
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Definition
| -left mid abdomen to pelvic canal/rectum (location can be variable) |
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Term
| Can we evaluate the mucosal surface of the large bowel with plain survey radiographs? |
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Definition
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Term
| What is the purpose of a pneumocolon? |
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Definition
-used to localize and ID the colon
-aids in determining large and small bowel
-often aids in the ID of a colonic intussusception |
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Term
| That are some of the causes of a colon that is decreased in size? (aka stricture) |
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Definition
-mural masses: neoplasia, granuloma, etc
-extramural masses: LN, prostate, etc
-inflammation: colitis
-spasm |
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Term
| What are some of the causes of a colon that is increased in size? |
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Definition
-Generalized: megacolon, esp in cats
-Localized: proximal to colonic obstruction, mass lesions, intussception |
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Term
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Definition
| -infrequent or difficult defecation associated with the retention of feces |
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Term
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Definition
| -contipatiion that is refractory to treatment, which occurs where there is permanent loss of function |
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Term
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Definition
-a persistent irreversible increase in colon diameter
-this is the most advanced stage in the spectrum of chronic constipation |
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Term
| How do we make a radiographic diagnosis of megacolon? |
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Definition
-history of chronic constipation/obstipaiton that is nonresponsive to medical treatment
-the presence of an enlarged distended colon filled iwth fecal mateiral |
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Term
| What are some examples of the causes of megacolon? |
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Definition
-traumatic pelvic canal narrowing
-nutritional
-metabolic
-idiopathic
-spinal anomalies
-neuromuscular dz
-perineal hernias
-congenital anomalies
-strictures
-sublumbar lymphadenopathy
-prostatomegaly |
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Term
| What are the three major types of intussusception? |
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Definition
| -ileocolic, cecocolic, and colocolic |
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Term
| How does an intussusception appear radiographically? |
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Definition
-variable
-soft tissue mass associated with the colon
-may appear as homogenous soft tissue opacity of the colon
-meniscus sign |
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