Lesson 8 - Introduction to Abdominal Radiographs 2

What is the radiolucency of positive contrast?

radioopaque

What is the radiolucency of negative contrast?

radiolucent

What are the types of GI studies?

1. esophagram

2. upper GI/Barium series

3. barium enema

4. barium sulphate suspension

What are the negatives of barium?

1. barium impedes scoping

2. barium in the small intestine can cause peritonitis

3. aspiration of barium is forever

What is the contrast study of choice for a canine patient with suspected GIT perforation?

positive contrast with oral iodinated contrast

What are the indications for barium esophagram?

1. esophageal foreign body

2. stricture mass

3. motility disorders

What are the type of urinary contrast studies?

1. excretory urogram

2. cystogram

3. retrograde urethrogram

What is an excretory urogram also known as?

intravenous pyelogram

How do you perform an excretory urogram?

intravenous injection of an iodinated contrast medium (Iohexal)

What are the contraindications for excretory urogram?

1. anuria

2. dehydration

3. hypersensitivity

When does the nephrogram phase start during an excretory urogram?

5-10 minutes

When does the pyelogram phase start during an excretory urogram?

10-20 minutes

When does the bladder start filling after starting an excretory urogram?

40 minutes

What are the types of cystograms?

1. pneumocystography

2. contrast cystography

3. double contrast

What is evaluated with a cystogram?

1. location/patency of the bladder

2. wall thickness

3. presence of calculi

4. presence of mass

What is positive contrast cystogram used for?

suspected bladder rupture

What contrast do you not use for cystogram?

barium

What is a pneumocystogram used for?

demonstrate wall thickness and structural abnormalities

What type of cystogram is no longer necessary?

pneumocystogram

What are the reasons for change in stomach position?

GDV

What are the reasons for increased opacity of the stomach?

1. foreign bodies

2. pyloric outflow tract obstruction

What are the reasons for decreased opacity of the stomach?

GD/GDV

What are the reasons for increase in stomach size/wall thickness?

1. gastritis

2. neoplasia

3. GDV

4. gastric dilatation

Which direction and degree of torsion is more common?

1. clockwise

2. 90 degrees

3. 360 degrees

Where does the pylorus move with GDV?

dorsal and cranial

Where does the fundus move with GDV?

ventral and to the right

On a right lateral view the pylorus is filled with air, what might be causing this?

Gastric dilatation volvulus

What are the radiographical signs of GDV?

1. compartmentalization sign

2. splenic displacement

3. pylorus filled with air on right lateral

What are some possible radiographical signs of GDV?

1. decreased liver size

2. esophageal dilation

3. peritoneal effusion

4. small intestinal dilation

5. free peritoneal gas

What is a frequent cause of chronic vomiting in dogs?

chronic obstruction

What are the causes of pyloric outflow obstruction?

1. functional disturbance

2. mass

3. fibrosis

4. inflammation

5. hypertrophic pyloric stenosis

6. chronic hypertrophic pyloric gastropathy

What are the radiographic signs of pyloric outflow obstruction?

1. gastric dilation

2. gravel sign

What is the gravel sign?

indigestible granular material present on radiograph

What vomiting is associated with gastric foreign bodies?

acute vomiting

What diagnostics do we need to perform for a non-radiopaque foreign body or neoplasia in the stomach?

contrast or ultrasound

What are the radiographical signs of gastritis?

1. gastric wall thickening

2. thickening and/or increase in the number of rugal folds

What radiographical sign may be seen with uremic gastritis?

mineralization

What are the most common gastric neoplasms in the dog and cat?

1. malignant lymphoma

2. adenocarcinoma

3. leiomyosarcoma

4. leiomyoma/adenoma

What type of hernias can cause displacement of the intestines?

1. inguinal

2. diaphragmatic

3. perineal

4. body wall

What type of hernia is an incidental finding in cats?

diaphragmatic hernia

What are the causes of generalized ileus?

1. functional

2. mesenteric torsion

What are the causes of localized ileus?

1. intussusception

2. chronic partial obstruction

3. foreign bodies

What are the causes of intestinal disease without ileus?

1. neoplasia

2. linear foreign body

3. enteritis

What is the common clinical presentation for intestinal disease without ileus?

diarrhea and upper GI signs if closer to the stomach

What are the radiographical signs of intestinal disease without ileus?

1. diffuse thickening

2. corrugation

3. bunching

4. higher than normal ratio of fluid to gas

5. gravel sign

What are causes of small intestine corrugation other than intestinal causes?

1. pancreatitis/peritonitis

2. pancreatic tumors

3. carcinomatosis

What neoplasias in dogs cause SI thickening and corrugation?

1. adenocarcinoma

2. lymphoma

3. leiomyosarcoma

What neoplasia in cats cause SI thickening and corrugation?

1. lymphoma

2. adenocarcinoma

3. mast cell tumor

What infiltrative diseases cause SI thickening and corrugation?

1. lymphoma

2. IBD

3. pythium

What benign lesions can cause SI thickening and corrugation?

1. polyp

2. leiomyoma

If you see generalized distension of the SI with ileus, what do you think?

1. functional ileus

2. distal mechanical obstruction

If you see localized distension of the SI with ileus, what do you think?

mechanical obstruction

What is the radiographical sign of ileus?

distension of the small intestine with fluid or gas

What are the functional causes of ileus?

1. bacterial overgrowth

2. hypokalemia

3. dysautonomia

How to tell the difference between a proximal or distal small intestinal obstruction?

proximal would have more severe signs and more localized distension

What are the radiographic changes with mechanical ileus?

1. mainly gaseous dilatation in the early stages

2. loops may show stacked or hair-pin appearance

3. two populations of bowel

When do you usually see a gravel sign with SI ileus?

distal small intestinal chronic partial obstruction

What type of foreign body is reported more frequently in cats?

linear foreign body

What radiographic changes are seen with linear foreign body?

1. plication

2. shortening of affected segment

3. intestine in central region

4. ileus in dogs

Where do most linear FB's lodge in dogs?

pylorus

Where do most linear FB's lodge in cats?

under the tongue

You see teardrop/crescent-shaped gas bubbles in the small intestine on a radiograph. What might be the problem?

linear foreign body

What can intussusception be primary or secondary to?

1. intestinal parasites

2. focal neoplastic lesions

3. linear foreign body

4. systemic disease

What animal is intussusception common in?

neonates with pre-existing intestinal motility disorders

Where is a common site for intussusception?

ileocolic junction

What is intussusception in the ileocolic region thought to be secondary to?

hookworm parasitism

Where are ileo-colic intussusceptions seen on radiographs?

mid-abdomen, caudal to the stomach, displace the remainder of the small intestine caudally

What can intussusception look like on radiographs sometimes?

1. elongated, sausage shaped soft tissue opacity

2. gas opacity may outline the crescenteric end of the bowel segment

What are the indications for cutting a patient open?

1. mechanical obstruction

2. regional ileus

3. two population of bowel

4. free abdominal air

5. palpable abdominal mass or opaque foreign body

What are the common causes of megacolon?

1. chronic constipation and nutritional, metabolic, or mechanical problems

2. chronic renal disease

3. persistent subclinical dehydration

4. idiopathic in cats

5. neurologic disease

What ratio of colon diameter to length of L5 suggests constipation?

1.28-1.48

What ratio of colon diameter to length of L5 suggests megacolon?

1.48

What is an issue that can occur with the cecum?

cecal inversion into the colon

What is the radiographic finding seen with cecal inversion?

soft tissue opacity in the right mid-abdomen and no normal air-filled cecum present

What is a change of number seen with kidneys on radiographs?

one kidney/renal aplasia

What causes a change in position of kidneys?

hernia/rupture

What causes an increase in opacity with the kidneys?

1. mineralization

2. fluid

What causes a decrease in opacity with the kidneys?

gas

What causes a decrease in size with the kidneys?

1. dysplasia

2. chronic kidney disease

3. congenital renal disease

4. end-stage renal disease

What are the main causes of renomegaly with smooth contour?

1. lymphosarcoma

2. hydronephrosis

3. perinephric pseudocyst

4. acute nephritis

What causes renomegaly with irregular contour?

1. neoplasia

2. renal cyst

3. polycystic kidney disease

4. feline infectious peritonitis

5. abscess

What type of mineralizations can occur with the kidneys?

1. nephrocalcinosis

2. nephrolithiasis

What is nephroocalcinosis?

dystrophic parenchymal mineralization

What can cause gas in the kidneys?

emphysematous pyelitis/ureteritis

What type of renal calculi are common in cats?

calcium oxalate

What type of renal calculi are common in dogs?

1. calcium oxalate

2. struvite

What causes ureteral dilation?

1. secondary to obstruction

2. obstruction from bladder mass

3. calculi or luminal mass

4. ligation during surgery

What can be seen on radiographs with renal failure?

free fluid in the retroperitoneal space that may extend into the peritoneal space

What is a common complication of chronic renal disease?

renal secondary hyperparathyroidism

What are the earliest and most dramatic radiographic changes seen with renal secondary hyperparathyroidism?

demineralization of the skull and mandible like floating teeth

What causes a change in contour/shape of the bladder?

neoplasia or rupture

What causes a change in position of the bladder?

1. hernia

2. distension

3. mass effect

What causes an increase in opacity of the bladder?

1. calculi

2. sand

3. foreign body

4. dytrophic mineralization

What causes a decrease in opacity of the bladder?

emphysematous cystitis

What causes a decrease in size of the bladder?

rupture with decrease serosal definition

How can male dogs have a change in number with the urinary bladder?

the prostate can mimic a second bladder with a paraprostatic cyst

What point in the body is used to estimate the size increase of the bladder?

apex of the bladder in relation to the umbilicus

How do patients present when they have a ruptured bladder?

collapsed with abdominal distention

What can cause a cranial displacement of the bladder?

distention due to obstruction

What can cause the bladder neck to be in the pelvic cavity?

20% of dogs normally have it located there or associated with incontinence