Equine Abdominal Ultrasound

Question 1

what are 7 indications to perform abdominal ultrasound in horses?

Answer 1

1. colic
2. weight loss
3. diarrhea
4. organ dysfunction (based on bloodwork)
5. fever of unknown origin
6. hypoproteinemia
7. ADR

Question 1

what is NOT visible with the transcutaneous abdominal ultrasound in horses?

Answer 1

• small colon
• nongravid uterus
• ovaries
• aorta and associated vessels
• abdominal lymph nodes
• mesenteric root

these are all potentially visible with transrectal ultrasound.

transcutaneous AND transrectal ultrasound both show: cecum, large colon, spleen, kidneys, bladder.

Question 2

what organs are visible with the transcutaneous abdominal ultrasound that are NOT visible with transrectal ultrasound in horses?

Answer 2

• stomach
• duodenum
• liver
• both kidneys

Question 3

To image the equine abdomen, what Mhz probe should we use?

Answer 3

1-5 MHz

we want a low frequency to get greater depth. but we must recall that low frequency means low detail.

Question 4

What can you do instead of clipping a horse in order to ensure good ultrasound visualization?

Answer 4

use a coupling agent such as isopropyl alcohol or ultrasound gel.

Question 5

Which of the following is/are NOT found on the RIGHT side of the horse?
A. right kidney
B. duodenum
C. stomach
D. cecum
E. right dorsal colon
F. right ventral colon
G. jejunum
H. liver

Answer 5

C. stomach

Question 6

what organs can be found on the LEFT side of a horse? (there are 7-8)

Answer 6

• left kidney
• spleen
• left dorsal colon
• left ventral colon
• small colon
• jejunum
• stomach
• sometimes liver

Question 7

What is FLASH ultrasound?

Answer 7

technique in colic cases to image specific locations that are MOST likely to identify visible abnormalities in many cases of colic.

Question 8

As compared to eachother they kidney is more ________ than the liver.

Answer 8

hypoechoic (black/dark)

Question 8

As compared to eachother they spleen is more ________ than the liver.

Answer 8

hyperechoic (white/light)

Question 8

The liver is best imaged on the (right/left) of the horse, just below the ventral lung border

Answer 8

RIGHT

Question 9

What should a normal appearance of the liver be on u/s?

Answer 9

sharp margins
branching vascular pattern
no bile ducts seen

Question 10

which side of the horse is the spleen best seen on?

Answer 10

LEFT

it is superficial to all abdominal organs.

Question 11

what is the normal appearance of the spleen?

Answer 11

granular homogenous appearance with few blood vessels.
it is hyperechoic compared to the liver.

Question 12

What location(s) are best to find the right and left kidneys?

Answer 12

right – rostral PLF
left – deep to spleen in PLF (more caudal that the right kidney is and deeper)

Question 13

Why is imaging near the spleen and kidney so important?

Answer 13

to rule out nephrosplenic entrapment

the nephrosplenic space is a potential space where the colon can get trapped.

Question 14

When evaluating the GI tract on ultrasound, what 5 parameters are we considering?

Answer 14

1. diameter (varies depending on section of GI tract but should be less than 5-6 cm)
2. motility (should move ALL the time)
3. wall thickness (normal is 3-4 mm, stomach can be up to 7.5 mm)
4. location
5. contents

Question 15

what are the 4 layers of the GI tract and their echogenicity on ultrasound?

Answer 15

1. serosa (hyperechoic / white)
2. muscularis (hypoechoic / black)
3. submucosa (hyperechoic /white)
4. mucosa (hypoechoic / black)

usually all layers are not visible.

Question 16

T/F: when measuring wall thickness of the GI tract, you should include the gas layer within the segment of the intestine.

Answer 16

false
this is a common mistake