Chapter 38 and 39 Principles of Abdomen and The Peritoneal Space Flashcards Preview

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Flashcards in Chapter 38 and 39 Principles of Abdomen and The Peritoneal Space Deck (51):
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Fig. 36-1 Lateral views of the abdomen illustrating the effect of different amounts of abdominal fat. A, Obese
cat. Extensive fat deposition in the falciform, omental, mesenteric, and retroperitoneal areas provides contrast
between viscera. Metallic objects represent vascular clips from a previous ovariohysterectomy. B, Normal cat.
Fat deposition is less than that in A, but it is adequate to allow visualization of viscera. C, Emaciated cat.
Without interposed fat, border effacement of viscera is present, producing a uniform, homogeneous abdomen
devoid of contrast except for gas in the bowel loops. D, Normal 2­month­old golden retriever. Poor contrast is
caused by a relative lack of fat in this young subject; this is a normal fnding.
 

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Fig. 36-2 Lateral view of the abdomen of a cat with a large volume of
intraperitoneal fluid. Homogeneous soft tissue opacity is distributed uni
formly throughout the distended abdomen. No fluid is in the retroperito
neal space, but fascial planes and organs in the retroperitoneal space are
not visible because of superimposition of the peritoneal fluid.
 

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Fig. 36-3 Lateral radiograph of the midabdomen of a dog with perito
neal fluid. There is a mottled, hazy, irregular fluid opacity within the
abdomen leading to blurring of the margins of soft tissue structures. This
radiographic appearance could be caused by the presence of an exudate
or hemorrhage, but in this dog it was caused by hypoproteinemia.
 

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Fig. 36-4 Lateral view of the abdomen of a cat with peritoneal fluid.
Serosal detail in the intraperitoneal space is obliterated, but there is good
visualization of fascial planes and fat in the retroperitoneal space. The
falciform fat in the cranioventral aspect of the abdomen, which is extra
peritoneal, is also normal. Comparison of the appearance of the fat in the
intraperitoneal versus retroperitoneal spaces can assist in the radiographic
detection of either retroperitoneal or intraperitoneal disease. There is also
renal mineralization and a large calcifed peritoneal body.
 

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Fig. 36-5 Lateral view of the abdomen of a dog with rodenticide toxic
ity. There is fluid opacity in the retroperitoneal space with blurring of the
margin of the lumbar musculature and a streaky appearance to the retro
peritoneal fat. Note the normal sharp serosal margin detail and contrast
within the intraperitoneal space.
 

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Fig. 36-6 Close­up of the cranioventral aspect of the abdomen of a dog with a ruptured splenic hemangiosarcoma leading to peritoneal carcinomatosis. The mottled appearance of the mesenteric fat is typical of carcinomatosis.
 

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Fig.  36-7 A, Lateral radiograph of the cranioventral aspect of the abdomen of a dog with a ruptured bowel that has led to pneumoperitoneum. Extraluminal gas in this patient appears as small gas bubbles in a location not expected for bowel (black arrows). The location of this gas is a good indicator that it is extraluminal. Had these gas collections been located in the midaspect of the abdomen, they might not have been rec
ognized as abnormal. B, Horizontal­beam abdominal radiograph of the same dog as in A. The dog was placed in left recumbency and a horizon tally directed x­ray beam was used to make the radiograph. The free peritoneal gas has collected beneath the right abdominal wall (white arrows). The more cranially located gas is in the lung (black arrowhead).
There is more free intraperitoneal gas than would be estimated from the conventional lateral projection in part A.
 

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Fig. 36-8 A, Lateral survey radiograph of a cat with abdominal effusion and a large amount of free intraab
dominal gas with margins of the gas pocket indicated by black arrows. B, Lateral survey radiograph of the
abdomen of a dog immediately after laparotomy. A large volume of free abdominal gas outlines the caudal
surface of the right crus of the diaphragm, the cranial pole of the right kidney, the caudal surface of part of
the liver, and the serosal surfaces of some bowel loops.
 

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Fig. 36-9 Lateral view of the abdomen made with the patient in dorsal recumbency with the cranial abdomen slightly elevated, and the use of a horizontally directed x­ray beam.

Free abdominal gas has accumulated between the diaphragm (white arrow), the liver (black arrow), and the ventral abdominal wall. The diagnosis was ruptured stomach.
 

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Fig. 36-10 Lateral view of a dog with pneumomediastinum. The pneumomediastinum is not visible in this image. Some of the mediastinal gas dissected along the fascial planes through the aortic hiatus into the retro peritoneal space (white arrows).
 

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Fig. 36-11 Lateral radiograph of a cat with a focal calcifed body in the peritoneal space. The calcifed body was an incidental fnding and thought to be a result of dystrophic calcifcation of necrotic fat.
 

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Fig. 36-12 Lateral view of the caudal abdomen of a 13­year­old Shetland sheepdog in chronic renal failure. The aorta and external iliac arteries (black arrows) are visible because of metastatic calcifcation.
 

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Fig. 36-13 Lateral view of the abdomen of a dog with tubular gas opaci ties (white arrows) ventral to the abdominal wall from an inguinal hernia with entrapped small intestine within the hernia. The level of the abdominal wall is indicated by the black arrows.
 

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Fig. 36-14 Sagittal sonogram of a dog with ascites. Anechoic fluid is present between and surrounding liver lobes. The lack of echoes in the fluid is consistent with the fluid being of low cellular content.
 

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Fig. 36-15 Sagittal sonogram of a 6­ year­old dog with an abdominal mass and peritoneal effusion. Free peritoneal fluid (white arrows) with low­level echoes is compatible with highly cellular fluid.
 

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Fig. 36-16 Sagittal sonogram of a 9­year­old dog with peritoneal metastasis, which is seen as hypoechoic, irregularly shaped material (*) interspersed through the more echogenic mesenteric fat. A small amount of anechoic peritoneal fluid is present on the right edge of the image (#).
 

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Fig. 36-17 Abdominal sonogram of a dog with a small amount of peritoneal gas. Even small gas collections create strong reflective artifacts (white arrow).
 

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Fig. 36-18 Lateral view of the abdomen of a normal dog. Note the fat opacity within the retroperitoneal space. Ill­defned nodular soft tissue opacities in the caudal retroperitoneal space seen ventral to L6 (black arrows) represent end­on projections of the deep circumflex iliac arteries and veins, not lymph nodes.
 

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Fig. 36-19 Lateral view of the abdomen of a dog with anal gland adenocarcinoma. The medial iliac lymph nodes are mildly enlarged and appear as an ill­defned soft tissue mass (white arrows) in the retroperitoneal space ventral to L7. The colon is displaced ventrally.
 

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Fig. 36-20 Lateral view of the abdomen of a dog with lymphosarcoma.
Medial iliac lymph node enlargement is severe and appears as a soft tissue mass in the retroperitoneal space extending caudally from L4­L5 into the pelvic canal (white arrows).
 

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Fig. 36-21 Lateral view of the abdomen of a dog with metastatic mast cell tumor. A large soft tissue mass caused by enlargement of the medial iliac lymph nodes extends from L3­ L4 into the pelvic canal, displacing the colon and rectum ventrally.
 

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Fig. 36-22 Sagittal (A) and transverse (B) sonograms of a normal medial iliac lymph node. On the sagittal
view, the lymph node (black arrows) is elongated and just ventral to the aorta near the aortic bifurcation. The
lymph node is nearly isoechoic to surrounding structures and has a thin echogenic capsule. On the transverse
image, the lymph node (black arrows) is a curved structure just ventrolateral to the aorta. Ventral is to the top
(A and B), and cranial is to the left (A).
 

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Fig. 36-23 Sonographic appearance of abnormal lymph nodes. A, Enlarged, hypoechoic medial iliac lymph
node (white arrow) surrounding the aorta in a dog with lymphosarcoma. B, Enlarged jejunal lymph node (white
arrows) in a dog with lymphosarcoma. This lymph node is hypoechoic to surrounding tissues and is irregular
in shape. C, Enlarged jejunal lymph nodes (black arrows) in a dog with inflammatory bowel disease. Lymphoid
hyperplasia was found on evaluation of lymph node aspirates. Both lymph nodes are hypoechoic and appear
similar to those seen in the dog with lymphosarcoma (B). D, Enlarged ileocolic lymph nodes in a cat with
lymphosarcoma. The ileum (black arrowhead) is seen in cross section surrounded by enlarged hypoechoic lymph
nodes (black arrows). E, A large mixed echogenic mass in the midabdomen of a dog. The mass incorporated
intestinal segments. Gas (black arrow) within one bowel segment is seen as an echogenic focus producing
acoustic shadowing. The hypoechoic to nearly anechoic areas were presumed to be enlarged mesenteric lymph
nodes because lymphosarcoma was diagnosed from aspirates of these structures.
 

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Fig. 36-24 Ventrodorsal radiograph of a normal cat. The left limb of the pancreas is visible (black arrow).
 

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A, Lateral survey radiograph of a dog with increased irregular soft tissue opacity in the midcranial
to cranial abdomen as a result of localized peritonitis (between black arrows). This is a diffcult assessment to
make; recognizing this change requires high­contrast radiographs and a patient with adequate abdominal fat.
 

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Transverse ultrasonographic view of the right limb of the pancreas in the same dog. Note the pancreas
(white arrows) is enlarged, hypoechoic, and irregular in shape, and the surrounding mesentery is hyperechoic.
The diagnosis was pancreatitis.
 

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Fig.  36-26 Sagittal sonogram of the pancreatic region of a normal dog. The pancreas (black arrows) is the poorly defned structure adjacent to the liver, having approximately the same echogenicity as the mesentery.
The hypoechoic structure in the middle of the pancreas is the pancreaticoduodenal vein.
 

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Fig. 36-27 Transverse sonogram of the right lobe of the pancreas of a dog with mild pancreatitis. The pancreas is less echogenic than normal, is hypoechoic to surrounding fat, and lies just ventral to the liver and medial
to the duodenum (black arrowhead). The pancreaticoduodenal vein is the round anechoic structure within the pancreas.
 

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Fig. 36-28 Sagittal sonogram of the right lobe of the pancreas in a dog with pancreatitis. The pancreas is enlarged and hypoechoic, and the surrounding mesentery is hyperechoic. This is a common appearance in dogs with moderate to severe pancreatitis.
 

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Fig. 36-29 A, Sagittal sonogram of the right limb of the pancreas in a dog. A large pancreatic abscess is
present with a thick hyperechoic capsule and less echogenic internal contents. B, Sagittal sonogram of the right
limb of the pancreas in a dog. A solid, midlevel echogenic pancreatic tumor is present adjacent to the duodenum
(top right).
 

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Fig. 36-30 Lateral (A) and ventrodorsal (B) radiographs of a 14­year­ old dog. A large mineralized mass is
present caudal to the stomach and just to the right of midline (black arrows). The mass is a malignant functional
adrenocortical tumor causing hyperadrenocorticism. A small amount of mineralized ingesta is present within
the pyloric region of the stomach.
 

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Fig. 36-31 Lateral (A) and ventrodorsal (B) radiographs of an 8­year­old domestic cat. The adrenal glands
are mineralized (black arrows). The left adrenal gland is not visible in the ventrodorsal image because it is
superimposed on the spine. This fnding is clinically insignifcant.
 

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Fig. 36-32 Sagittal sonograms of a left (A) and right (B) normal canine adrenal gland. A, The left adrenal gland has a dumbbell shape and lies just ventral to the phrenicoabdominal vein (black arrow). It is less echogenic than surrounding fat.

B, The right adrenal gland is seen as an elongated hypoechoic structure just dorsal to the caudal vena cava (black arrow). The right adrenal gland in this dog is surrounded by a hyperechoic capsule. The phrenicoabdominal vein (white arrow) is less often visualized on the right side. The head is to the left and
ventral to the top.
 

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Fig.  36-33 Sagittal sonogram of the left adrenal gland (cursors) of a dachshund with pituitary­dependent hyperadrenocorticism. The adrenal gland has a plump appearance but is normally shaped. The gland is enlarged, measuring 2.6 cm in length and 1.0 cm in thickness. The hypoechoic cortex can be differentiated from the more echogenic medulla. This layered appearance has been described in normal dogs and in dogs with  hyperadrenocorticism. The white arrow points to the aorta.
 

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Fig. 36-34 Sagittal sonogram of the left adrenal gland of a 12­year­old mixed­breed dog. A hyperechoic nodule is present in the cranial pole of the adrenal gland. The ultrasonographic appearance of this nodule is not specifc and could be caused by neoplasia (varying types), granuloma, or nodular hyperplasia.
 

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Fig. 36-35 Transverse sonogram of the right adrenal gland (white arrow)
of a 13­year­old Shih Tzu with hyperadrenocorticism. The adrenal gland is enlarged, round, and of mixed echogenicity, containing hyperechoic nodules. Histopathologically, the adrenal gland contained myelolipomas and adenomas.
 

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Fig. 36-36 Sagittal sonogram of the left adrenal gland of the same dog as in Figure 36­30. The adrenal gland is seen as a large, curvilinear hyper echoic line (black arrow) with distal acoustic shadowing, consistent with the appearance of mineral. The diagnosis was adrenocortical tumor.
 

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Fig. 38.1 Right (A) and left (B) lateral radiographs of the cranial aspect of the abdomen of a cat with acute
vomiting. In the right lateral view (A), the stomach contains gas and there is heterogeneous material in the
duodenum (white arrow), but there is no diagnosis. In the left lateral view (B), gas from the stomach flls the
proximal aspect of the duodenum outlining a foreign object (black arrow), confrming a bowel obstruction.
 

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Fig. 38.2 Ventrodorsal (VD) abdominal radiographs from two dogs. In A, the pelvic limbs are flexed, allowing
relaxation of the caudal abdominal muscles and greater expansion of the caudal aspect of the abdomen. In B,
the pelvic limbs are pulled caudally, creating skin folds (white arrows) that can interfere with interpretation,
and the caudal aspect of the abdominal cavity is narrower and more crowded. Also in B, the edge of the positioning
trough has created a linear opacity (black arrows) that can also interfere with interpretation. (Reprinted from
Thrall DE, Robertson IR: Atlas of radiographic anatomy and normal anatomic variants in the dog and cat, ed 2,
St Louis, 2016, Elsevier/Saunders., p 243.)
 

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Fig. 38.8 Right lateral radiograph of a normal dog where fluid has collected in the pylorus (black arrow). The fluid-flled pylorus has a mass like appearance, which can be confused with a gastric mass or a gastric foreign body.
 

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Fig. 38.9 Right lateral (A) radiograph of the abdomen of a dog suspected of having a linear foreign body.
There is fluid in the pyloric antrum (black arrows) and anchoring of the foreign body is not visible. In a left
lateral view (B), with air in the pyloric antrum, the portion of the foreign material anchored in the pyloric
antrum is clearly seen (black arrows) due to the contrast provided by the gas.
 

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Fig. 38.10 Lateral (A) and dorsoventral (DV; B) radiographs of the abdomen of a 15-year-old pug with acute
abdominal distention and thoracic pain from rib fractures. In the lateral view (A), there was concern whether
the dilated stomach was in a normal or abnormal position. The thoracic pain precluded obtaining a ventrodorsal
(VD) abdominal radiograph, so a DV was obtained instead. In the DV view (B), gas has risen to the fundus
because this part of the stomach is nondependent. There is no evidence of gastric malpositioning or gastric
compartmentalization, which are common features of gastric volvulus. This illustrates one of the few indications
for obtaining a DV view of the abdomen versus a VD view. Note the increased crowding of the abdomen and
the superimposition of the pelvic limbs on a portion of the abdomen, which are common problems with DV
compared with VD abdominal radiographs.
 

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Fig. 38.11 Lateral radiograph of the cranial aspect of the abdomen of a
7-year-old American miniature horse. The small size of this horse allows
for reasonable radiographic quality, but the conspicuity of organs is less
than in a dog or cat because of the relatively reduced amount of abdominal
fat and the larger volume of the abdomen occupied by the gastrointestinal
tract. There is a small amount of sand in the ventral aspect of the large
bowel (white arrow); this is not signifcant. Horizontal gas/fluid interfaces
(black arrows) in the bowel are seen because the radiograph was made
with a horizontally directed x-ray beam. Visualization of gas/fluid interfaces
to this extent is normal in the horse.
 

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Fig. 38.12 Lateral radiographs of the cranioventral (A) and midventral (B) aspects of the abdomen of a
10-year-old standardbred horse. The massive size of the abdomen of adult horses, the large volume of the
abdominal cavity that is taken up by the gastrointestinal tract, and the relative lack of fat prevent visualization
of abdominal detail to the same extent as in dogs or cats, or even foals. However, some abnormalities can be
detected. In this horse, the cranioventral aspect of the abdomen in A is devoid of any detail because of the
extreme thickness of this region and the relatively homogeneous contents of the bowel; this is a normal
appearance. However, this is a common location for sand to accumulate, and clinically insignifcant segmental
accumulations are seen here. In B, there is a large circular radiopaque structure in the ventral aspect of the
abdomen that represents an enterolith (black arrows).
 

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Fig. 38.13 Right-left lateral radiograph of the cranioventral aspect of the abdomen of an adult Holstein
suspected of having traumatic reticuloperitonitis. There is a magnet in the reticulum (white arrow) but no
evidence of metallic foreign material. When a left-right lateral (B) was made, a wire (black arrows) is visible
cranial to the reticulum confrming a penetrating foreign body from the reticulum. The reticulum magnet is
again visible in B. The wire was not visible in the right-left radiograph because of magnifcation due to the
increased distance of the wire from the cassette. When the patient was radiographed from the opposite side,
the wire was much closer to the cassette and was not blurred by magnifcation.
 

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Fig. 38.14 Lateral radiograph of a cat with abundant fat in the abdominal cavity and retroperitoneal space. The fat provides contrast, and there is excellent discrimination between parenchymal organs. The kidneys, proximal
aspect of the spleen (white arrow), jejunal segments, and the urinary bladder are all highly conspicuous because of the peritoneal fat. Note the large collection of fat in the falciform ligament (black arrows).
 

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Fig. 38.17 Lateral radiograph of a cat with jejunal crowding in the central abdomen because of excessive omental and mesenteric fat. There are no other signs of a linear foreign body to justify attributing this appearance to anything but crowding caused by excessive fat. Small nephroliths are also present.
 

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Fig. 38.16 Lateral radiograph of an 11-week-old dog. Conspicuity of serosal margin detail is diminished because of the relative lack of abdominal fat; this is a common fnding in young animals. Margin visualization is, however, better than in patients who are undernourished and emaciated (compare with Fig. 38.15).
 

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Fig. 38.18 Ventrodorsal (VD) view of the caudal aspect of the abdomen in a male dog. The summation opacity created by the prepuce (white arrows) can be misinterpreted as a mass. Note also the skin folds created by pulling the pelvic limbs caudally (black arrows) rather than having them flexed during radiography.
 

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Fig. 39.36 Lateral (A) and ventrodorsal (B) radiographs of a 14-year-old dog. A large mineralized mass is
present caudal to the stomach and just to the right of midline (black arrows). The mass is a malignant functional
adrenocortical tumor causing hyperadrenocorticism. A small amount of mineralized ingesta is present within
the pyloric region of the stomach.
 

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Fig. 39.37 Lateral (A) and ventrodorsal (B) radiographs of an 8-year-old domestic cat. The adrenal glands
are mineralized (black arrows). The left adrenal gland is not visible in the ventrodorsal image because it is
superimposed on the spine. This fnding is clinically insignifcant.
 

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