Introduction to Abdominal
Radiology
Meghan Woodland, DVM
Indications
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Vomiting/Diarrhea
Abdominal Pain
Hematuria
Abdominal Mass/Distension
Tenesmus (Pain on Defecation)
Technical Factors
• Abdomen has low inherent contrast
– Lower kVp
– Higher mAs
• Collimation
– High amount of scatter
– Use grid (if patient is >10-11cm thick)
• Take exposure on expiration
Positioning
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VD and R lateral views
Include from diaphragm to pelvic inlet
Fore limbs pulled cranially
Hind limbs pulled caudally
Additional views as necessary
Radiographic techniques: the dog
By Joe P. Morgan, John Doval, Valerie Samii
Radiographic techniques: the dog
By Joe P. Morgan, John Doval, Valerie Samii
Improper
positioning.
Could miss a
diaphragmatic
hernia.
Unprepared Abdomen
“Butt Shot” – Urethral Calculi
Interpretation of Abdominal
Radiographs
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Liver
Spleen
Kidneys
GIT (Stomach, SI, Cecum, LI)
Bladder
Prostate
Extra-abdominal structures
Structures Not Normally Seen
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Gall bladder
Pancreas
Adrenals
Ovaries
Uterus
Ureters
Lymph Nodes
Mesentery
Vasculature
Liver
• Lateral view:
– Caudo-ventral margin angular
– Should not extend beyond the costal arch
– Normal gastric axis parallel to ribs or perpendicular
to spine
• VD view:
– Liver margins not well seen
– Long axis of stomach perpendicular to spine
Over-inflation of chest gives false appearance of enlarged liver
Spleen
• Size is subjective
• Lateral view:
– Tail of spleen visible, but position varies
– Not usually seen on this view in cats
• VD view:
– Head of the spleen is visualized
• Caudo-lateral to stomach fundus
• Cranio-lateral to left kidney
– Cats : often seen lying along the left body wall
Dog – Lateral View
Dog – VD View
Cat – Lateral View
Cat – VD View
Kidneys
• Right located cranial to left
• May be difficult to see in young or emaciated
animals
• Size (only evaluated on VD view)
– Dogs: 2 ½ to 3 ½ times the length of L2
– Cats: 2 to 3 times the length of L2
Dog – Lateral View
Dog – VD View
Cat – Lateral View
Cat – VD View
Gastrointestinal Tract
• Stomach
– Caudal to liver
– Gastric Axis
– Less than 3 ICS wide on lateral view
– VD:
• Dog = U-shaped
• Cat = J-shaped
“U-Shaped” Stomach
Dog – VD View
“J-Shaped” Stomach
Cat – VD View
Gastrointestinal Tract
• Small Intestine
– Size: Width less than 3 times the last rib
– Duodenum
• Fixed along the right side
• Extends caudally from the pyloric region of the stomach
– Jejunum/Ileum
• Position Varies
• Mid-ventral abdomen
Gastrointestinal Tract
• Cecum
– Comma shaped
– Mid, right abdomen
– Not often seen in cats
• Large Intestine
– Ascending, transverse and descending colon
– Size: Width less than 5 times the last rib
Cecum – VD View
Cecum – Lateral View
Megacolon in a Dog
Descending colon
Transverse Colon
Ascending Colon
Transverse Colon
Ascending Colon
Descending colon
Contrast Study
Bladder
• Size varies
• Dog:
– Oval to ellipsoid
– Caudal abdomen or pelvic
• Cat:
– Ellipsoid
– Always intra-abdominal (elongated bladder neck)
Bladder more
pelvic
Dog – Lateral View
Long Bladder Neck
Cat – Lateral View
Prostate
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Intact males ++
Caudal to bladder
Symmetrical with smooth margins
Size:
– Lateral: Less than 70% of sacro-pubic distance
– VD: Less than 50% of pelvic inlet width
Extra-Abdominal Structures
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Soft Tissues
Bone (Spine, Pelvis, Hind limbs)
Diaphragm
Thorax (if visible)
Decreased Abdominal Detail
• Inability to distinguish organs
• Causes:
– Young Animals *
– Emaciated Animals
– Peritoneal Fluid
– Inflammation (Peritonitis, Pancreatitis)
– Carcinomatosis
 Normal finding
Emaciated Cat
Abdominal Fluid
Fun Slides
How Many
Babies?
Where is the
foreign body?
What organs are mineralized?
????
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THE END!