Abdominal Imaging II

1. Stomach

2. Cecum

3. Ascending colon

4. Descending colon

5. Small intestines

1. Descending duodenum

2. Ascending colon

3. Stomach

4. Trans colon

5. Cecum

6. Ascending duodenum

7. Small intestines

8. Descending colon

9. Rectum

1. Cardia

2. Fundus

3. Body

4. Pyloric antrum

5. Pyloric curvature

Dog vs cat stomach

Cat stomach is smaller, have fat in the submucosa, and pyloric sphincter is on midline or to the left

Dog pylorus is to the right of midline

On a left lateral view, there should be __ in the pylorus and __ in the fundus.

Gas, fluid

On a right lateral view, there should be __ in the pylorus and __ in the fundus.

Fluid, gas

Important view sequence in a suspected GDV

Start w right lateral - most sensitive, diagnostic

VD is next important view

Common presentation of dogs with a GDV

- large/giant breed dog

- non productive retching

- possible abdominal distension

- signs of obstructive shock (tachycardia, hypotension, poor pulse quality)

Radiographic findings of a GDV

PYLORUS DORSAL AND TO THE LEFT

Generally a gas filled stomach

+/- splenomegaly

Compartmentalization - soft tissue “band” that crosses the stomach, represents stomach folding onto itself

Pneumatosis or pneumoperitoneum

Megaesophagus

Small intestinal dilation

What is gastric pneumatosis?

Gas visible within the gastric wall

In cases of GDV, may be a poor prognostic indicator

May have to do some sort of gastric resection in surgery

True or false: food bloat is a surgical emergency.

False

Presentation of dogs with food bloat

- non productive retching

- abdominal distension

- abdominal pain

- lethargy/anorexia

Radiographic appearance of food bloat

- stomach is distended by heterogenous soft tissue opacity (not gas)

- stomach is normally positioned within the abdomen

Food bloat can be difficult to distinguish from...

Pyloric outflow obstruction

How can we differentiate food bloat from a pyloric outflow obstruction?

Repeat rads following medical management (IV fluids, pain meds) and 12 hour fast - gastric content should be moving through GI

Diagnosis of gastric foreign bodies on rads

Repeat rads following a 12 to 24 hour fast - food will have passed into SI and foreign material will likely linger

What view do we need to diagnose a pyloric outflow obstruction?

Left lat

Appearance of pyloric outflow obstruction

Gas halo surrounding soft tissue opaque material in pylorus

Diagnosis of gastric masses

Normally cannot be seen - need contrast study, ultrasound, CT

Common gastric tumors in dogs vs cats

Dogs - adenocarcinoma

Cats - lymphoma

Appearance of uremic gastropathy

Mineralization of the gastric wall on rads/ultrasound

Normal SI size

Dogs < 1.5 x the height of the mid aspect of L5

Cats < 12 mm

What is mechanical ileus and what is seen radiographically?

Obstructed SI lumen

- any combo of opacities

- 2 populations of small intestine, one more dilated than the other

Causes of mechanical ileus

- foreign material

- luminal mass

- extra luminal mass

- stricture

What is functional ileus and what is seen radiographically?

Decreased motility from vascular or neuromuscular abnormalities of the GI wall

- gas opaque

- generalized dilation

SI size parameters in the dog - normal and abnormal

Max serosa-serosa diameter/height L5

Normal is < 1.6 x height of L5 vertebral body

SI max/L5 between 1.6-2.4 may be obstructed

SI max/L5 > 2.4 very likely obstructed

SI size parameters in the cat - abnormal

Abnormal > 1.6 x the height of the cranial endplate of L5

Abnormal > 12mm

Gastric pneumatosis

Mechanical ileus

Functional ileus

Food bloat

Mechanical ileus

Gastric dilation

GDV

Gastric dilation