Ultrasound of the GI and Pancreas Flashcards
Can the GI tract be ultrasounded form end to end?
NO
Transverse and longitudinal planes of the GI tract are in relation to..
The axis of the bowel not the patient.
GI contents (with abdominal ultrasound)
Greatly affect your ability to perform the exam.
What type of probe should you use for GI ultrasound?
High frequency (7.5 to 10 MHz) need good definition.
Important to fast the patient for how many hours before a GI ultrasound?
6 to 12 hours.
What can you do prior to GI ultrasound to improve ability to visualize?
Give water prior to examination and reposition the animal during the exam to improve visibility
Detailed evaluation of the GI tract is difficult in..
Full of ingesta or fluid.
Anxiety or painful patients, resulting in straining
Large/deep chested patients.
What are you evaluating on GI ultrasound?
Wall thickness of the stomach, small intestines, duodenum and colon.
Wall layers
Content
Motility
Lesions (extent of lesions, regional lymphadenopathy, and obstruction)
What is the normal wall thickness on ultrasound of the stomach?
5-8 mm
What is the normal wall thickness on ultrasound of the small intestine?
2-4 mm
What is the normal wall thickness on ultrasound of the duodenum?
4-6 mm
What is the normal wall thickness on ultrasound of the colon?
2 mm
What can you evaluate about lesions during an GI ultrasound?
Lesions (extent of lesions, regional lymphadenopathy, and obstruction)
*View ultrasound GI + pancreas lecture; slide 6
View the views of the stomach, duodenum and colon in different views.
What is the white line in the middle of the ultrasound of the bowel?
Lumen (black surrounding is the mucosa)
*View ultrasound GI + pancreas lecture; slide 8
View the stomach in cross section and longitudinal view
*View ultrasound GI + pancreas lecture; slide 8
View the stomach in cross section and longitudinal view
*View ultrasound GI + pancreas lecture; slide 9
View gastric contents in the stomach.
*View ultrasound GI + pancreas lecture; slide 10
View gastric contents in the stomach, fluid in the stomach.
Gastric mucscularis is ________ than bowel mucscularis relative to the mucosa.
Gastric mucscularis is THICKER than bowel mucscularis relative to the mucosa.
*View ultrasound GI + pancreas lecture; slide 11
View the small intestine (duodenum and jejunum)
*View ultrasound GI + pancreas lecture; slide 12
View normal feline ileum and ICJ
Longitudinal and transverse
What is the normal size of mesenteric (jejunal) nodes?
1-2 mm thick normally (often don't see) Mildly enlarged (2-3 mm)
mesenteric (jejunal) nodes enlarged due to..
Normal in puppies
Reactive nodes (may or may not be significant)
*View ultrasound GI + pancreas lecture; slide 13
What are GI disorders?
Inflammatory disorders Tumors Ulcers Foreign objects Intussusception
What are inflammatory GI diseases?
Examination can be normal. Wall layers altered but still present (thickening of mucscularis or submucosa, increased echogenicity of mucosa).
Thickening of the wall (mild to moderate)
Usually multiple segments involved
Regional lymphadenopathy (mild to moderate)
What is lymphocytic plasmacytic enteritis?
Hyperechoic speckles in the mucosa, mildly enlarged mesenteric (jejunal) nodes
- View ultrasound GI + pancreas lecture; slide 16 and 18.
- thickened mucscularis relative to mucosa.
What is IBD and Lymphangietasia?
Seen in the duodenum and jejunum.
May see Lymphangietasia with IBD or lymphoscarcoma.
May see dilated lymph ducts with recent meal.
*View ultrasound GI + pancreas lecture; slide 17
Ultrasound of gastrointestinal tumors:
Wall thickening (moderate to severe) Loss of layering*** big neoplasia sign Obstruction is possible especially with CA > LSA > smooth muscle tumors.
Ultrasound of gastrointestinal tumors:
Wall thickening (moderate to severe)
Loss of layering*** big neoplasia sign
Obstruction is possible especially with CA > LSA > smooth muscle tumors.
Regional lymphadenopathy is common.
What are the common GI tumors?
Lymphoma (often longer segment is affected)
Carcinoma (shorter segment)
Smooth muscle tumors
IBD, LSA, and MCT tend to be..
diffuse with mild to moderate mucscularis thickening or mass effect in the wall.
*MUST get samples for diagnosis.
Images are shown as examples, not specific diagnosis.
IBD, LSA, and MCT tend to be..
diffuse with mild to moderate mucscularis thickening or mass effect in the wall.
*MUST get samples for diagnosis.
Images are shown as examples, not specific diagnosis.
*View ultrasound GI + pancreas lecture; slide 23
Not uniform thickening, more likely to be cancer
Mass
*View ultrasound GI + pancreas lecture; slide 23
Not uniform thickening, more likely to be cancer
Mass
*View ultrasound GI + pancreas lecture; slide 24
Colonic carcinoma.
*View ultrasound GI + pancreas lecture; slide 25
Leiomyosarcomas
Focal masses in the bowel wall are..
Non-specific, you need to get a sample for diagnosis!
Gastric ulcers on ultrasound:
Local (focal) thickening (focal loss of layers)
Crater with gas bubbles at the crater site.
Decreased gastric motility
Intraluminal fluid accumulation
Finding gastric ulcers on ultrasound..
Ulcers are hard to find. Not finding doesn’t rule out!
May be seen with FB, inflammatory disease or tumors or own their own.
If you find ulcer, check for signs of perforation.
*View ultrasound GI + pancreas lecture; slide 28
Gastric ulceration
*View ultrasound GI + pancreas lecture; slide 29
Peyers patch = psudoulcer
Foreign material in the GI tract..
Evaluate the size, shape and echogenicity
Usually have a bright interface with strong shadowing.
Evidence of obstruction (accumulation of intraluminal fluid oral to object.
Variable GI motility.
*View ultrasound GI + pancreas lecture; slide 31
Ball foreign objects.
Foreign bodies in the GI tract, tend to cause..
fluid accumulation orally and empty bowel aborally.
*View ultrasound GI + pancreas lecture; slide 32
What will you observe on ultrasound with linear foreign objects?
Plication of the bowel.
Usually a linear hyperechoic interface in a longitudinal plane.
Maybe small an difficult to visualize in a transverse plane.
Variable shadowing.
Placated bowel.
*View ultrasound GI + pancreas lecture; slide 33
What are other reasons for plicated bowel, not due to linear FB?
Metoclopramide therapy, ischemia, or inflammation may mimic linear foreign objects.
*View ultrasound GI + pancreas lecture; slide 35
Signs of intussusception?
Too many layers
Bright intussuscepted fat
Fluid accumulation
Decreased motility
*View ultrasound GI + pancreas lecture; slide 36
*View ultrasound GI + pancreas lecture; slide 37, 38
Intussusception
GI ultrasound tips:
Ultrasound is useful for detecting and localizing GI disorders.
Two problems can be occurring at the same time! (tumor + ulcer)
The US appearances of inflammation and neoplasia are the same.
Biopsy is needed for definitive diagnosis.
Ultrasound of the pancreas:
Almost isoechoic to surrounding fat.
May not be visible despite a good US window.
Need to use landmarks to maximize chances to see.
Pancreas anatomy
Consists of right and left lobes and central body.
Closely associated with the stomach, liver and duodenum.
Contains a central duct and vessel.
Dog: usually see vessel in right lobe
Cat: usually see duct in the left lobe.
*View ultrasound GI + pancreas lecture; slide 42
Right lobe of the pancreas in dogs.
Adjacent to the duodenum.
Usually see vessel in the right lobe.
*View ultrasound GI + pancreas lecture; slide 43
Caudal to the stomach.
Ventral/cranial to the splenic vein.
Cat: usually see duct in the left lobe.
*View ultrasound GI + pancreas lecture; slide 44
Right limb, left limb and body of the pancreas.
What are common pancreatic disorders?
Pancreatitis (psudocyst or abscess) Pancreatic neoplasia (carcinoma and Insulinoma)
Pancreatitis findings on ultrasound?
Hypoechoic (enlarged pancreas) Hyperechoic surrounding fat. Thickened/corrugated duodenum. Distended duodenum Pain when pressure is applied.
A normal pancreatic ultrasonogram..
does not rule out pancreatitis
Especially poor sensitivity in cats.
Underlying or concurrent neoplasia cannot be ruled out.
Recheck if signs persist.
Sonographic signs may persist after clinical signs abate*****
*View ultrasound GI + pancreas lecture; slide 48
Pancreatitis
*View ultrasound GI + pancreas lecture; slide 49
Pancreatic psudocyst/abscess
Pancreatic psudocyst/abscess
Sequela to acute pancreatitis. Cannot be differentiated by ultrasound (unless gas is present= abscess) Irregular fluid-filled cavity. Variable wall Surrounding bright fat
Pancreatic tumors:
Appear as hypoechoic/mixed echogenic nodules or masses in the region of the pancreas.
Surrounding parenchyma may not be seen.
Metastases commonly present
Difficult to differentiate from regional lymphadenopathy.
*View ultrasound GI + pancreas lecture; slide 51
Pancreatic carcinoma
Neoplasia of the pancreas and pancreatitis…
Appear very much the same!
*View ultrasound GI + pancreas lecture; slide 52
Insulinoma
*Normally small and indistinct lesion
*View ultrasound GI + pancreas lecture; slide 53
Benign nodular hyperplasia
Tips when ultra sounding the pancreas:
The normal pancreas is difficult to look at.
GI and vascular landmarks are key to finding the pancreas.
Cant make diagnosis without biopsy.
Aspirate and/or recheck ultrasound may be needed.