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medsurg
11/6/98
wortman

exam questions, by the way, will 
have slides
there will be 8 multiple choice questions from him, and 4 
will be based on slides.

we finished yesterday talking about 
radiographic signs of esophageal disease. opacity, size, position, 
function. we talked about changes in opacity that could be a variation of 
normal as that due to aerophagia or could be pathological. 

changes in 
radiographic opacity of the esophagus:

neck rad, 10 yr old female 
sheltie, hx gagging, voice change, regurgitation
we see a change in 
opacity - a radiolucency of varying diameter is present in neck, 
following dorsal to trachea. also irregular soft tissue swelling in 
cranial neck, and some change in diameter of trachea near that. 


constrast esophagram of same dog - irregular filling through whole neck 
region. filling defects in esophagus. some contrast in larynx. so there 
is some diffuse disease here. dx was thyroid tumor that had invaded into 
the esophagus and impaired function.

this is a 6 yr old WHWT. this chest 
rad shows a large, air filled stomach with a large white area cranial to 
the diaphragm, dorsal to the heart. this is a bone density in the 
esophagus - we can tell b/c we see a white line cranial to it 
representing the dorsal border of the esophagus, and an airfilled 
structure ventral to that, ventral to which is the ventrally displaced 
cranial trachea. 
we think this dog has a bone stuck in the esophagus. 
this is one of the three high incidence locations of esophageal FB - 
cardia of stomach. also base of heart is another area, as in this other 
rad we are now seeing. here we see contrast outlining the FB, and some 
contrast in stomach. the other main area is the thoracic inlet - here we 
see a chicken foot - can identify the digits of the foot. 

changes in 
size of esophagus: the main one we see is an enlargement, since normal 
sized esophaguses usually do not show up on rads.
slide: 5 mo old female 
sheperd x. increased opacity in cranial chest - some fluid/gas in caudal 
thoracic esophagus. trachea is very ventrally deviated. so the cranial 
esophagus is very dilated. the trachea is on the sternum. the mottled 
opacity is food in the esophagus mixed with fluid and air. 

slide: 
contrast of this same animal. ooh, could this be a vascular ring 
anomaly?? there is a big outpouching cranial to the heart. there is a 
marked constriction at heart base; then contrast does pass beyond it. he 
says this appearance puts him in mind of vascular ring anomaly, PRAA. 
also there could be loss of function of cranial esophagus and you have to 
know if this will improve or not. if there is underlying motility 
disorder, surgery may not be so helpful. we see filling defects within 
the caudal esophagus - probably food. 

VD - same animal - marked cranial 
widening of esophagus. the outpouching is visible as a white blob.  this 
marked distension occurs when your esophagus tries and tries to propel 
food and eventually has to distend b/c it cant propel food. slide: line 
drawing showing ligamentum arteriosum constricting esophagus.

another 
type of diverticulum can occur in addition to this propulsion type. there 
is a traction type, where scar formation pulls esophagus with it as scar 
contracts, seen post esophagotomy. 

slide: in horse, post esophagotomy - 
as it healed, a scar formed and pulled esophagus toward skin surface. 


slide: very dilated esophagus. this 5 yr old OES was regurgitation (o 
reported vomiting) also had atrophied masseter and temporal muscles, and 
was progressing to generalized muscle atrophy. this esophagus is very 
wide, filling whole chest dorsal to heart, and causing ventral tracheal 
deviation. on the VD view we see two parallel white lines running through 
chest vertically that shouldnt' be there. we also see evidence of 
pneumonia and cavitary lesion - aspiration?

changes in function:


sometimes we are asked to document functional problems - can do 
esophograms, watch how it responds to a food bolus. if you watch 
fluoroscopically, you can see what happens to it. should go down quickly 
in a rapid swoop. sometimes sticks at thoracic inlet, base of heart, 
cardia, and gets pushed by secondary peristalsis. sometimes doesn't move 
at all.

that same OES - bolus in midthoracic esophagus, moving along to 
caudal esophagus. there is no functional esophageal tone, though. the 
food is sloshing in the esophagus. this dog has megaesophagus. sort of a 
controversial dx. but radiologically just means a big distended 
esophagus, of any cause. 

hx vomiting and regurgitation since weaning in 
3 month old puppy
air filled esophagus, ventrally deviated trachea 

contrast esophagram - distension of esophagus cranial to heart base, 
narrowing at heart base, distension in caudal thorax as well. what is 
this? megaesophagus? vascular ring and megaesophagus? normal? not normal 
:). looks like it is constricted at heart base. but, here, in a right 
lateral radiograph, it looks distended all the way through. the weirdness 
on left lateral is because of the normal left aorta. the esophagus just 
drapes there and looks constricted. so this is just megaesophagus. 
looking back on survey rad, there is no constriction at the heart base, 
so you would not have thought of vascular ring anomaly. but you use right 
lat view to ddx b/w ring anomaly and megaesophagus w/o ring anomaly

11 
yr old spayed irish setter 
hx coughing, occasional vomiting for years

listless a few weeks, not barking well, good appetite, weight loss
there 
is an irregular soft tissue opacity in caudal thorax, right next to the 
diaphragm. if this were in the esophagus we would expect esophagus to be 
air filled and dilated cranial to it, which we do not see. we know she's 
been coughing. that could be pneumonia from aspiration but this is 
probably a lung lesions. the VD view localizes mass to the midline, 
caudal thorax. 
esophagram looks normal but esophagus is dorsally 
deviated by this papillary carcinoma of the lung. 

slide: that WHWT with 
the bone in esophagus - note differences - the tumor is more ventral, 
though both masses are in caudal/dorsal chest. the bone rad shows a 
dilated air filled esophagus cranial to the bone.

slide: cat radiograph 
- mass in dorsal caudal chest - the question is, is this pulmonary or 
esophageal?  cranial to it is a well defined air opacity. there is slight 
ventral deviation of the trachea. the esophagram shows obstruction at the 
site of the mass, which is an SCC protruding into and occluding the 
lumen. this animal was regurgitating. 

dog was chained outside, saw 
something, wanted to run, ran and got hurt by chain, had change in voice 
and started regurgitating. we see ventral deviation of trachea, increased 
lucency above it, what appears to be distended air filled structure in 
dorsal chest. dx here is what? megaesophagus, probably from vagal nerve 
injury. contrast study - new survey rads were done...now, there is a soft 
tissue density in the caudal dorsal chest! what is that? is it the 
stomach? contrast shows obstruction and the contrast is trying to outline 
it - it is the tstomach, gastroesophageal hernia or gastroesophageal 
invagination. the megaesophagus is a predisposing factor for this - this 
is when the stomach protrudes into the lumen of the esophagus. 

Stomach 
and Small Bowel:
the Upper GI study: UGI or upper GI study. 
indications:

recurrent or refractory vomiting or diarrhea
must be at least some 
vomiting to warrant this study
hematemesis or melena
suspected GI foreign 
body or obstruction
abdominal mass
confirmation of various herniae


standard UGI study: 
ensure proper patient preparation
-survey rads

-administer barium sulfate
-serial radiographic evaluation

patient prep: 

withold food x 24 hrs
mild cathartic at start of fast sometimes used
1-2 
warm water enemas - one the evening before, one the morning of UGI

acepromazine if sedation required
remove (stop giving) symptomatic 
motility inhibitors prior to study!

survey rads: always take at least a 
lateral rad to ensure proper patient preparation. also to evaluate 
appropriate technique, esp if previous rads taken elsewhere. also 
provides basis for comparison, and sometimes may provide the dx. 

barium 
sulfate: barium sulfate USP is not recommended. this is the chemical 
grade stuff available in most pharmacies. doesn't enter suspension well, 
is poor medium. Barium sulfate, micropulverized - much better, stays in 
suspension better - if it comes out of suspension that indicates blood or 
mucus present, is a sign of disease. dosage: 20-40% w/v solu'n, 10-12 
ml/kg

sometimes we use iodinated contrast if suspecting perforation:

gastrograffin - squibb product: 37% meglumine diatrizoate
oral hypaque - 
winthrop product: 40% sodium diatrizoate
dose: 1-2 ml/kg, 50 ml maximum 
dose. hyperosmolar, don't give too much.
many feel barium is still 
preferred despite potential risks; lawyers suggest we should not use it, 
due to risk of complication. barium study is more sensitive


complications:
barium: aspiration, peritonitis
iodine products: 
dehydration, shock

slide: baby orangutan drinking barium from can. most 
animals will not do this. use a syringe to give per os in the buccal 
pouch, or use a tube to avoid the mess - orogastric in dogs, nasogastric 
in cats. 

serial evaluation - dog:
VD and RLR at 15, 30, 60 minutes, 
then hourly
additional views as needed: LLR, compression, 24 hr
study is 
complete when contrast reaches the colon and the stomach is empty

serial 
evaluation - cat:
VD and RLR at 5,30, 60 minutes, then hourly. barium 
progresses much more quickly, usually study is done much sooner. of 
course this is in normal animals. abnormal animals may have hypermotility 
or hypomotility.

we usually actually start with a VD, DV, RLR and LLR 
b/c their is air and fluid in stomach and we want a really good 
evaluation.

slide: barium and air in stomach. aniaml in LLR. so, fluid 
is falling into the fundus, and the right side, the antrum, is gas 
filled. so on the rad the barium looks dorsal and air looks ventral.


slide: same animal in RLR - barium is in antrum and gas is in fundus, and 
we see fundic mucosal detail. so now barium looks ventral and air looks 
dorsal.

VD or DV:
for DV, fluid is in antrum and air is in fundus
for 
VD, fluid is in fundus and air is in antrum or body

this is important 
esp for ddx gastric dilatation and gastric dilatation and volvulus

acute 
gastric enlargement: GD and GDV
you need to tell these apart. tend to 
occur in giant dogs. 
slide: as stomach distends, usually the greater 
curvature is being moved further and further out, while lesser curvature 
stays the same. 

--break---

this is often a confusing topic for 
students - if it wasn't confusing for you, you might be in engineering 
school. but you need to learn this. damn. damn.  next year in rounds, you 
will be asked about this.

so, this radiograph of a large dog with 
abdominal pain and distension...
we see a big stomach. the question is if 
it is GD or GDV, because GDV has to go to surgery. this is a LLR 
radiograph. ok, so that means fluid falls to the fundus and air to the 
pyloric antrum. normally we should see pylorus now, then. but, er, I do 
not see it, it all looks like a giant round stomach. Here in the RLR view 
of the radiograph we see the air filled pylorus dorsally. it has flipped 
over, it shouldn't be there. the rounded fundus is not air filled. the 
tubular antrum is. seeing gas filled tube on RLR means pylorus is on the 
left side. it shouldn't be there so you have a GDV. 

air in peritoneal 
cavity is another complication - this rad shows us air outlining a liver 
lobe - could be iatrogenic from trocharization or orogastric tube, or 
spontaneous rupture.

slide: left lat - air filled stomach
slide: right 
lat - we see pyloric antrum better. here whole stomach is air filled


slide: free gas in peritoneum the day after orogastric intubation; due to 
trauma from tube. remember heightened serosal detail is a sign of 
pneumoperitoneum.

common technical errors:

inadequate patient 
preparation - can cause confusion trying to interpret films and can 
affect transit time.
lack of survey rads- may make you unable to decide 
if something is real
insufficient contrast
incomplete serial evaluation


Radiographic signs: again -
size, shape, location, opacity, number, 
function!!

evaluation of UGI study:
size of lumen
thickness of wall

mucosal pattern
intraluminal contents
continuity of contrast column

flexibility/motility of wall
position of stomach and bowel
gastric 
emptying time
small bowel transit time

slide: cross section drawing of 
bowel 
if you do find a filling defect, is it from lumenal object, 
something in wall, or something outside gut?
another thing to look at is 
mucosal pattern - how contrast interfaces with mucosa. normally smooth. 
can look cobblestoned, can be filling defects, can be deviations, etc.


slide: fluid filled bowel loops - some gas filled - barium present in 
bowel. in some areas looks fimbriated -that's normal. 
slide; 
hypersegmented area of proximal small bowel - sometimes called 'string of 
pearls' appearance - hyperperistalsis, more common in cat and esp in 
proximal duodenum. sort of like appearance of linear foreign body. but 
the general course of bowel looks ok, no rapid turns, so probably not.


slide: dog was vomiting and having loose bloody stool. GI study next day 
3 hrs post administration of contrast shows precipitation/flocculation of 
barium - remember this suggests wrong kind of barium or blood/mucus in 
gut. we see irregularity of mucosa. this is catarrhal enteritis related 
to heavy worm burden . wormed it, it did fine.

3 yr old american eskimo 
dog with hx vomiting a few hours after eating.
this radiograph shows  
multiple gas filled bowel loops, that probably are small bowel loops, and 
some of them show thickened appearance to wall. thick white areas 
following airfilled areas. it is hard to judge thickness of wall on 
survey film, though, b/c beam is vertical and bowel loop contains 
air/fluid. fluid filled bowel will look thickened. if gas column looks 
strange, that could be associated with abnormal bowel wall thickness. but 
you have to confirm by palpation, signs or contrast study. 

7 hrs post 
barium - delayed gastric emptying, should be empty by 3-5 hrs but isn't. 
we see a pretty, wavy pattern - looks like ramen noodles to me! linear 
foreign body? well, notice the bowel is uniformly distributed throughout 
abdomen. this is really marked infiltration of bowel wall, affecting th 
elumen. it's infiltrative inflammation. grossly the bowel was very thick, 
tubular, sort of ridged looking. 

another pattern you may see - an area 
of bowel where there is a wider port of barium, then an indentation next 
to it - infiltrative process - histoplasmosis; LSA; severe IBD looks like 
this. this is called "stack of coins" appearance sometimes. 

here is a 
large filling defect - hard to see serosal margin near the defect, but 
there sure looks like an obstructive lesion here invading into the gut. 
barium only passes on one side so this probably originates from the wall 
- intramural filling defect.  this was a leiomyosarcoma

this is a rad 
from about 1 hr post barium administration. the stomach has a filling 
defect - we see the caudal border looking ok, then a shelf like 
appearance to the cranial border of the fundus - that's the mucosal 
surface. so the diaphragm or the stomach wall is thick. probably stomach. 
probably intramural defect. diaphragmatic lesions are rare. this is 
gastric carcinoma. 

ulcer pattern - little outpouches of mucosa in this 
survey rad of duodenum. these are "pseudoulcers" - these are peyer's 
patches on the duodenum. these are normal. you can tell from regular 
ulcers by location in duodenum and by absence of abnormal bowel wall or 
lumen. if it were an ulcer, wall would be abnormal.
a true ulcer would 
probably look like a crater filled with barium, and a mound of 
circumferential tissue forming a collar. looking down on it will look 
more like a donut of no barium with barium outside and inside. the ridge 
won't have barium on it.

CRF animal - has an ulcer - central 
radioopacity ringed by radiolucent ring.

gastric emptying time: initial  
10 -15 minutes; total 1-4 hours.
some nervous small breed dogs have 
delayed emptying when they are upset. cuddle them first. :) 
small bowel 
transit time: in duodenum by 15-30 minutes, in jejunum/ileum at 30-60 
minutes, at ileocolic junction by 1.5-2 hrs in dog, faster in cat; 
cleared upper GI and in ileum and colon by 3-5 hrs.

chronic gastric 
enlargement (for acute - ddx GD, GDV):
mechanical obstruction: neoplasia 
(gastric, duodenal, pancreatic), pyloric hypertrophy, pyloric stenosis, 
foreign body, diaphragmatic hernia
functional obstruction: pylorospasm, 
small intestinal disease

[waaah. i am soooooo cold...]

Yorkie - 
vomiting for some months. some alopecia. vomited shortly after eating. 

survey rad - large structure in ventral cranial abdomen = stomach. very 
distended. the antrum shouldn't be >1/2 diameter of fundus. fundus must 
be huge.
VD: stomach is very distended, has a lot of food in it. this 
animal has been vomiting. if a vomiting animal has food in the stomach, 
think about that. was it just now fed, or is it not really food?


contrast: 1 hr post barium - you can see there is delayed gastric 
emptying b/c barium is not emptying into small bowel. 
lateral 2 hrs post 
barium - still we only see contrast in the stomach. it's obscuring 
everything else in there. this is really a giant hairball though. hey, 
that explains the alopecia, doesn't it. now, it could be hair on top of a 
tumor so you have to be careful about giving a prognosis prior to 
surgery.

rad of cat with hx gagging, anorexia, vomiting x 10 days. 
dehydrated. force feeding food but it vomits. survey rad shows gas filled 
area of stomach with food in it. we see good serosal detail of peripheral 
bowel loops. some gas distension of small bowel loops ome of which has 
weird shape - linear foreign body - bowel is all bunched together in one 
area. now this is also typical of fat cat. differentiate b/w scrunching 
of bowel - hair pin turns of linear fb; and bunching of bowel in fat cat


VD view - oral hypaque given - causes mucosal edema, btw - we see dilated 
bowel loops, marked hairpin turns - linear fb. stomach holds top of 
pantyhose. 

this 5 yr old cat has hx complete inappetance x 3 weeks, 
lost 7 lbs, is now 12 pounds down from 19 :). we see a large colon full 
of air and a piece of feces, we see gas filled small bowel loops, we see 
no stomach - makes sense, animal has empty stomach - it's there, just do 
not really see it. the bladder outline is clear. there is a bone density 
round thing just at the cranial edge of the bladder, and also over some 
of the intestines. doesn't look like it is associated with the other 
bowel loops. one bowel loop has more air in it. in lecture, abnormalities 
are in the middle of the rads, on exams, they are at the periphery, btw. 
so is this loop a small bowel loop or large bowel loop? we did a GI 
study. 

contrast rads: five minutes out - some barium in stomach, 
contrast filling duodenum and outlining something but now we gave more 
barium b/c this wasn't enough. 15 minutes - marked distension of distal 
duodenum, then normal appearing small bowel.  on VD that calcified round 
density is probably necrotic fat or hematoma that is calcified - it's 
very lateral, not associated with bowel. anyway, this cat had corncob in 
small bowel. 

this cat 1.5 yrs old, vomiting intermittently for a few 
days. gas filled stomach/bowel. this survey rad isn't giving us too much 
to go on. there is one bowel loop in ventral abdomen that might be fluid 
filled and distended. 
contrast rad: 15 minutes out. this is a right 
lateral b/c contrast is in antrum and fundus is gas filled. the DV shows 
us a distended bowel loop on the left side. at 30 minutes, and at 3 hrs - 
one small bowel loop has retained barium and has a filling defect in it. 
little rubber spider was in there.

excess gas and fluid in small 
intestines without dilation: this is sometimes confusing. can be due to 
aerophagia, recent enema, debilitated patient, enteritis, incomplete 
obstruction, malabsorption

if there is distention of the bowel, with 
excess gas and fluid:
consider nitrous oxide anesthesia, paralytic ileus, 
or mechanical ileus.

paralytic ileus: usually generalized involvement of 
small bowel. bowel usually uniformly dilated with mild rather than 
massive enlargement and minimal fluid content.

mechanical ileus: usually 
localized but can be extensive. usually non-uniform distension with 
moderate to severe enlargement. there is definite intraluminal fluid. 


sometimes in confusing cases, use of a horizontally directed beam is 
useful. stand dog up against vertically oriented plate and shoot 
sideways. if bowel is obstructed, air and fluid will be at different 
levels b/c of pressure differential. 

slide: a lot of air fluid 
interfaces - are these at the same level within single bowel loops? if at 
different levels, more likely mechanical. hard to interpret. 


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