Ultrasound - GI tract, pancreas, liver, spleen Flashcards
When performing an U/S exam, we need to pay attention to… (8)
Size
Shape
Location
Margination
Echogenicity
Architecture
Function/GIT peristalsis
Neighboring structures
In what cases should you U/S examine the stomach and intestines? (6)
Persistent or chronic vomiting
Diarrhea
Abdominal pain
Abdominal mass
Weight loss, anorexia
Foreign body ingestion
Landmark for finding the duodenum?
right kidney and then move left so the duodenum should be between pylorus and right kidney essentially
Which kidney is more cranial?
the right kidney
The gastric wall and intestinal wall has a characteristic…
layered appearance.
Ideal situation: no gas, fluid content, not overdistended, layering visible, wall thickness measurable.
The thickest layer of the intestines.
The mucosa is the thickest layer.
Cats particularly have a very prominent echogenic mucosal layer in the ileum.
Cats particularly have a very prominent …
echogenic mucosal layer in the ileum.
The layers of the large intestinal wall are often not clearly seen due to
the presence of gas and fecal material, causing acoustic shadowing.
The gastric wall is arranged forming
rugal folds.
Peristaltic and segmental contractions are normally seen at a rate of 4-5 contractions/ minute in the stomach and proximal duodenum.
In the mid abdomen the small intestinal contractions generally are seen 1-3 times/minute.
Peristaltic and segmental contractions in the stomach and proximal duodenum are normally seen at a rate
of 4-5 contractions/ minute.
In the mid abdomen, the small intestinal contractions generally are seen at a rate of
1-3 times/minute.
Name those layers.
serosa (one of thinnest)
muscularis (one of thinnest)
submucosa (one of thickest)
mucosa of GI lumen (one of thickest)
In cats, IBD and lymphoma affect what layers of the intestines?
muscular and submucosal layers so endoscopy won’t help you cause you need to go deeper I believe?
What is anchor movement seen on U/S?
When, due to an obstruction in the GI tract, lumen content is seen to move back and forth but not forward.
Indications for pancreatic U/S. (7)
Anorexia
Weight loss
Vomiting/Diarrhea
Abdominal pain
Abdominal mass
Hypoglycemia (insulinoma)
Icterus
Pancreas size/thickness in dogs and cats?
In dogs variable: 1-3 cm x 1 cm
Cats 0,5 – 1 cm
right limb, body and left limb are the parts of the pancreas
what side is the duodenum on?
primarily on the right
Echogenicity and shape of the pancreas on U/S.
Iso- to slightly hypoechoic to surrounding fat
(so fairly dark-grey, NOT super white at all)
Homogenous echotexture
Smooth borders, regular margination.
Leaf-like, triangular in cross-section.
left: severe pancreatitis + hypoechoic mass
right: pancreatitis in cat, anechoic pancreas
acute necrotizing pancreatitis
In dogs, pancreatitis is mostly
acute.
More clinically striking with more obvious U/S signs.
In cats, pancreatitis is mostly
chronic.
Vague clinical signs, “always” a differential.
Less obvious U/S signs than dogs have, maybe even normal on U/S. Feline pancreatic lipase immunoreactivity test should be done.
Cats often have nodular hyperplasia in their pancreas.
Indications for liver U/S. (8)
Hepatomegaly
Abdominal mass
Icterus
Ascites
Unspecific GI-disease
FUO (fever of unknown origin)
Search for metastasis
FNA/biopsy
Probe choice for liver U/S.
low frequency especially in a large animal
Hepatobiliary U/S technique.
on the right side of the animal as the gallbladder is towards the right
Evaluating size and shape of the liver on U/S for…
Small: PSS (portosystemic shunt), Hepatic fibrosis/ cirrhosis/ diaphragmatic hernia
Enlarged: Other diseases
Should have straight borders with sharp edges.
Evaluating echogenicity of the liver on U/S …
Homogeneous architecture and moderately echogenic, with an even , granular texture.
The gall bladder appears rounded with thin and smooth walls. The contents are usually anechoic.
Evaluating structure of the liver on U/S … assess what parts? (4)
Portal vein; hyperechoic wall, ventral to hepatic veins.
Hepatic vein; anechoic wall.
Hepatic artery; very small, adjacent to portal veins.
Bile ducts; not visible, ventral to portal vein.
echogenic material in cat gallbladder is normal?
The common bile duct starts at
the point where the cystic duct and the
first hepatic duct join.
How many bile & pancreatic ducts/papillae in dogs?
And in cats?
Dogs: (2 papillae)
* Common bile duct enters close to but not
merged with the pancreatic duct.
* Accessory pancreatic duct enters at minor
duodenal papilla 2 cm aborally (= side furthest from mouth).
Cats: (1 papailla)
* Common bile duct and pancreatic duct
merges before opening at major duodenal
papilla.
* Only 20% of cats have an accessory
pancreatic duct at minor duodenal papilla.
What is unique to cat gallbladders?
They can have bilobed gallbladder or multiple gallbladders and still be normal.
Normal gallbladder thickness, common bile duct width etc. measurements in dogs and cats.
ddx for hepatic lesions based on echogenicity
Review these changes in echogenicity of the liver.
upper left = normal
upper right = increased echogenicity (diabetes)
lower left = decreased echogenicity (lymphoma)
ddx for varying hepatic size
cirrhosis sees decreased size
Cushing’s can cause what to happen to the liver?
liver can be hyperechoic with hypoechoic nodules
gravity dependent, echogenic sludge within gallbladders
Cholecystitis in 3 animals.
upper right: cholecystitis and cholangiohepatitis
lower left: cholecystitis with mucocele, bile leakage due to necrosis and biliary peritonitis
Dynamics of biliary obstruction.
24h: distention of GB and cystic duct
48h: distention of common bile duct
72h: distension of hepatic ducts
5-7d: dilated biliary canaliculi
Gallbladder mucoceles.
Common secondary to Cushing’s.
Describe Biliary mucoceles.
Mucinous hyperplasia of the gallbladder wall without known cause etc. see image.
Where is the spleen located?
Where is its head located versus body and tail?
left abdominal wall region.
Splenic head:
constant position
Caudodorsal to the stomach.
Often Under the caudal rib cage.
Splenic body and tail:
variable position
Along the left abdominal wall, sometimes crossing the midline ventrally, sometimes visible cranial to the urinary bladder.
Indications for spleen U/S. (5)
Splenomegaly
Abdominal mass
Peritoneal effusion/hemoperitoneum
Abdominal pain, sudden weakness/collapse
Trauma patient
Splenic U/S technique.
How does the normal spleen usually look?
The spleen is a strap shaped organ that is roughly triangular in cross-section.
Splenic size is very variable. The size can increase with certain anesthetic agents.
The borders should be smooth with an echogenic capsule.
Distinct and sharp margins.
Homogenous parenchyma, hyperechoic to liver and kidney cortex.
splenic U/S
splenic U/S
ddx for splenic conditions
focal dz
multifocal dz
diffuse nodular dx
inhomogenous alterations (= not the same but not that different)
Pathologies that can be found in the spleen.
splenitis
histiocytic sarcoma
hemangiosarcoma
splenic abscess
hematoma
etc. etc.
various ways splenic neoplasia can look.
Leopard spots can mean lymphoma.
Describe hemangiosarcoma on U/S.
Can be in the heart, spleen or liver, skin.
Splenic often sends mets to the heart.
Describe abdominal lymph nodes on U/S.
Usually elongated shape and perivascular location.
Approximately isoechoic to the surrounding fat.
Slightly hypoechoic cortex and slightly hyperechoic medulla.
More prominent in young animals.
How to tell an adrenal gland from an abdo LN?
Adrenal gland won’t have a hypoechogenic cortex.
Describe abdominal blood vessels on U/S.
Consistent in location.
Provide important landmarks to identify structures.
Useful if normal anatomy is distorted.
Investigation of vascular disease.
