Abdominal Imaging 3

sihirlifil's version from 2017-11-30 17:25

GI Tract

Question Answer
NORMAL lateral abdomen: Asterisk?
Colon with fecal material
Is this normal?
YES!... and no
Arrows pointing to empty muscular pylorus not a mass! If want to make sure, flip dog to other side, move air from fundus to pylorus to make sure air moves in(good serosal detail b/c fat)
NB: calculi in bladder!
Normal VD view: arrows?
Top left arrow: Descending duodenum
Left arrowhead: Ascendinc colon
Top right long arrow: Fundus
Medium arrows: Descending colon
Which of these is RLR? LLR?
Left = RLR
Right = LLR
In RLR, air will be in the...Fundus (rises!)
IN LLR, air will be in the...Pylorus
Which recumbency?
Barium is heavy and falls to dependent side, which is the pylorus
Air is in the fundus
Which recumbency?
Barium falls to fundus (dependent side) and air rises into pylorus
Which recumbency? (which species?)
RLR in a cat. Barium falls into pylorus, air into fundus
What makes this NORMAL image look so funky?
Diet soda was given orally following small volume of barium. CO2 inflated the stomach, coated the stretched-out walls with barium
Can see rugal folds = radiolucent striped filling defects outlined by barium
Gas in fundus, Barium in pylorus, RLR
Which is VD? DV?
Left = VD (gas tends to lie in the body)
Right = DV (gas rises into fundus)
Images of 2 different animals: Is this normal?
YES! Left is VD of dog, right is VD of cat
Cat stomach lies to left of midline while the dog is more on midline
Is this normal?
Yep! Undulating peristaltic waves
What are the US planes?Each organ & structure scanned in 2 planes (structures often lie obliquely in the abdomen)
GI US: appearance depends on?Contents! Gas & ingesta make examination difficult
Fluid will act as an acoustic window
Empty GI = less artifacts! So fast the animal!
Use highest frequency transducer if possible
Which transducer is better, 5MHz or 8MHz? Why?8MHz! Higher frequency = Better resolution of the 5 layers of the stomach
Why is the GI often difficult to examine on US?Presence of gas
Wall thickness depends on?Degree of distension of GIT
(stomach <5-6mm, SI <4.5mm in dog, 2-2.5mm in cat)
Which layers can be seen on US longitudinal plane? (5)Lumen, mucosa, submucosa, muscularis, serosa (fibrous = BRIGHT)
From top to bottom, which layers are shown (transverse plane US)
Serosa (hyperechoic)
Muscularis (hypoechoic)
Submucosa (hyperechoic)
Mucosa (hypoechoic)
Lumen (hyperechoic gas-lumen jxn)
Dx? radiographic findings?
Gastric dilation
Can occur without torsion!
Esophagus distended with air, round ST opacity superimposed on left crus of diaphragm & stomach (may be in lungs or esophageal lumen) = tumor in lumen, causing megaesophagus & aerophagia
T/F in a case of gastric dilation, the diaphragmatic crura on both the LLR and RLR are parallelFALSE! You actually can't use the crura to decide which side the dog is lying on (Note air in duodenum on LLR)
Round radiolucent FB in pylorus (which is in midline!!!), filling defect
Barium outlines stomach & proximal small intestine
This is a LLR of abdomen. The RLR was unremarkable. Why does this matter?
Taking 2 opposing lateral views helps move gas around the GIT, which contrasts FB! (In this case round ST opacity within pylorus)
Arrow? any other abnormalities?
Mineral opacities = Gravel sign within the pylorus, which is caudally displaced
Stomach distended with fluid
FB causing pyloric outflow obstruction!!! (sits like valve at antrum)
How does the pylorus move during torsion?Towards the left and dorsally to variable leve, depending on degree of torsion
Line of soft tissue between the 2 dilated parts of the stomach
Dx? Radiographic abnormalities?
Gastric torsion 180*
Pylorus lies dorsocranially, gas-filled fundus ventrally
Rugal fold stripes in fundus
This torsion is INCOMPLETE, so less pronounced distension & no compartmentalization
Gastric displacement
Pylorus displaced to the LEFT by a right-sided mass
This is NORMAL! Barium is in fundus & pylorus

Stomach Ultrasound

Question Answer
What is being measured? (Stomach transverse)
Gastric wall measurement between rugae
How does a normal cat stomach look?Wagon wheel shape

How does a normal dog stomach US compare to a cat?More elongated

Long axis:
What’s going on? How do the rugal folds look?
Gastric displacement: gastric axis displaced caudally by liver mass
Rugal fold margins WIDENED & irregular to to chronic vomition & inflammation
Gastric wall neoplasm = soft tissue depression (filling defect)
Cranial indentation of caudal border of the gastric body
What pathology between short arrows? Long arrow indicates?
Gastric wall thickened by neoplasia, layers disrupted
Long arrow = hyperechoic gas in gastric lumen

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