Normal U/S abdomen Flashcards
T/F: Gastric gas hampers evaluation
TRUE
Where do you clip fur for an abdominal ultrasound?
10th-12th ICS
What veins/arteries are visible in the abdomen?
- Veins are Visible, arteries are not
- Portal veins
- hyperechoic wall
- enlarged = possible liver disease
- Hepatic veins
- isoechoic wall
- enlarged = possible CHF (congestion)
What are the arrows pointing to?
What 6 things should you evaluate when examining the liver?
- Size
- Margins
- Margination
- Echogenicity
- Architecture
- Lesions
T/F: Parenchymal changes are often unspeific and a biopsy should be taken for definitive diagnosis.
TRUE
When evaluating parenchymal changes, what other changes should you look for?
- Hepatomegaly
- Irregular margins
- Lymph node changes
- Ascites
- Assessment of other organs
What are the differential diagnoses for a diffusely hypoechoic parenchyma?
- Acute hepatitis
- Venous congestion (would also see enlarged hepatic veins)
- Lymphosarcoma
What are the differential diagnoses for a diffusely hyperechoic parenchyma?
- Diabetes mellitus
- Hyperadrenocorticism
- Hepatic lipidosis
- Lymphosarcoma
What diseases can be present even with a normal liver/parenchyma on an ultrasound?
- Acute hepatitis
- Toxic hepatopathy
- Diffuse infiltrative disease
What abdominal organ is this?
Gall bladder (both are normal–one on the right has ‘slush’)
What approaches can be used to examine the gall bladder on U/S?
- Retrocostal approach
- Intercostal approach
How does a normal gall bladder appear on U/S?
- The gall bladder is readily visualized
- Anechoic content, but sludge can be seen normally
- Gets bigger with anorexia or fasting
- Thin wall (1-2 mm), Isoechoic to liver parenchyma
Are intrahepatic biliary ducts normally seen on U/S?
No–they are not detected in the normal dog and cat
Can the common bile duct be seen in a normal U/S?
- Can be traced in the normal cat
- Usually not apparent in the normal dog due to overlying gas in the GI tract
How do the following appear on U/S of the gall bladder and biliary tree?
- Sludge
- Cholecystitis
- Choleliths
- Obstruction
- Sludge = normal
- Cholecystitis = thickened GB wall
- Choleliths = mineral: hyperechoic casting a clean shadow
- Obstruction = Dilation of GB and common bile duct
This is a normal gall bladder. What species is this?
Pussy cat
Where can you find the spleen for U/S?
- Splenic head fixated at the greater curvature of the stomach
- At the level of the costal arch
- Body and tail
- Position very variable
- Left and ventral abdominal wall
- The entire spleen must be examined!
What is the normal anatomy of the spleen on an U/S?
- Size very variable
- Hyperechoic capsule
- Smooth margins
- Splenic vein at hilus
- Homogenous fine granular appearance (liver has coarser appearance)
- Interior echo finer and denser than liver
- Compare echogenicity to left kidney
- Spleen > left kidney
What two organs are shown? Which has greater echogenicity?
Spleen and kidney
The spleen is hyperechoic to the kidney
What organ is this? is the structure outlined in red normal?
Spleen
Outlied structure is fat at the hilus–it is NORMAL!
What organ is this? What is represented by the red and blue areas?
Spleen (cat)
Red = artery, blue = vein (both at the hilus)
What is the normal ultrasonographic anatomy of the kidney?
- Renal medulla is segmented
- Clear cortico-medullary distinction
- Renal cortex < spleen
- Renal cortex > renal medulla
- Renal pelvis usually 1-2 mm wide
- Proximal ureter is enlarged if greater than 3-4 mm
T/F: Pelvic fat is causes the renal pelvis to be hypoechoic and is easily misdiagnosed.
FALSE–pelvic fat causes the renal pelvis to be HYPERechoic. DON’T misdiagnose this!
What organ is this? Which plane is it being viewed in?
Kidneyyyyyyyy
It is in the transverse plane!
What is the normal renal size in the cat and dog?
- Cat–3.66 +/- 0.46 cm
- Dog–??
What are the indications for ultrasound of the lower urinary tract?
- The urinary bladder and parts of the urethra not obscured by the pelvis are easily detected and identified
- Ultrasound is very useful for examining bladder neoplasia and calculi
Lower urinary tract examination
- Full urinary bladder
- Positional scanning
- Do both transverse and sagittal scan
- Ballottement
- Causing turbulences
What are the ultrasound features of the urinary bladder?
- U/S examination reveals an anechoic fluid-filled structure with a well defined wall visible
- Wall thickness, shape, contents are easily evaluated
- Normal wall thickness varies with bladder distention and weight of patient
- An empty bladder can appear thickened artifactually
Ultrasonographic anatomy of the stomach
- In close apposition with the liver cranially
- In the normal dog and cat the empty stomach lies cranial to the last pair of ribs
- May extend slightly caudal to costal arch
- Lies in a transverse plane, usually to the left of the midline
Let’s review the anatomy of the stomach:
- Cardia (gastroesophageal junction)
- Fundus
- Body (largest portion)
- Pyloric portion:
- Antrum (2/3 oral)
- Canal (1/3 aboral) contains double sphincter
Why perform an ultrasonographic exam on the stomach?
- May eliminate the need for gastric series
- Faster, gives more info
- Useful and complementary modality
- Less expensive and faster
- 12-hour fast
Normal measurement for the stomach on U/S?
What is the echogenicity of the various layers?
= 5 mm in diamter (must measure in the middle of the lumen space)
What are the ultrasonographic features of the stomach?
- With decreasing distention the rugal folds are more prominent
- Stomach wall thickness in a dog is 3-5 mm
- Stomach wall thickness in a cat is 2 mm
- Measure between rugal folds
- Peristaltic contractions 4-5 per minute
How do you assess the stomach on U/S?
- Combination of factors:
- Peristalsis
- Stomach content
- Wall appearance
- Symmetry
- Extend
- Other findings
- Major obstacle is gas in GIT
What organ is this?
Stomach
What is the intestinal wall thickness in dogs and cats?
- Duodenum
- Dog–5 mm
- Cat–3 mm
- Jejunum
- Dog–2-4 mm
- < 2.3 mm
- Ileum
- Dog–4 mm
- Cat–3 mm
What are the 5 layers of the intestine?
- Serosa–hyperechoic
- Muscularis–hypoechoic
- Submucosa–hyperechoic
- Mucosa (thickest)–hypoechoic
- Lumen-mucosa-interface–hyperechoic
Where is the normal feline ileum found? Which is the prominent layer?
- In right cranial abdomen, medial and ventral to right kidney
- Prominent hyperechoic submucosal layer
What is the mucous pattern of the small bowel?
- Collapsed state
- Hyperechoic
- Without acoustic shadowing
What is the fluid pattern of the small bowel?
Anechoical luminal content
What is the gas pattern of the small bowel?
- Hyperechoic
- With acoustic shadowing
- Walls often appear less distinct
What is the alimentary pattern of the small bowel?
- Appearance depends on type of food
What are the 2 comparisons for the ileus?
- Mechanical vs. functional
- Complete vs. partial
What organ is this? Why does it look like this?
Corrugated ileus
Secondary to peritonitis/pancreatitis
Normal wall layering of the large bowel?
- 5 layers: hyper, hypo, hyper, hypo, hyper
- More challenging to see due to a thinner wall
- Need a high resolution probe to resolve layering
Large bowel wall thickness?
- Dog–2-3mm
- Cat– <2mm
- Always appears thinner than adjacent small bowel
U/S features of large bowel (2)
- Often can only evaluate near the wall due to the presence of gas and feces
- Cecum in dogs is often difficult to identify due to intraluminal gas
What organs are these?
Small (left) and large bowel (right)
