Transcript General Abdominal Radiography - North Carolina State University

General Abdominal
Radiography
Tony Pease, DVM, MS
Assistant Professor of Radiology
North Carolina State University
Objectives
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Acquisition of radiographs
Abdominal radiographic anatomy
Radiographic patterns of abdominal disease
Determine normal compared to abnormal
Determine further evaluations needed
Reading
• Chapter 38
– Pages 483-493
Abdominal Radiography
• Generally being replaced with ultrasound
– Ultrasound does not give a global picture
• Radiographs are a snapshot of disease
– 1/120th of a second picture
• Ultrasound is real time
Abdominal Anatomy
• A lot of organs in a small space
• Rely on location
Acquiring radiographs
• Relatively high kVp (70)
– Moderate image contrast
– Some of shades of grey
– More than bone less than thorax
• Moderate mAs
– Minimizes motion artifact
– Maximizes contrast
• Enemas and fasting are helpful
Positioning
• Include caudal thorax
• Try to include greater trochanter of femur
• Center beam just caudal to the last rib
Large patients
• May need two films
per view
– Four films per study
– Make sure to
overlap images
Ventrodorsal
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Liver
Spleen
Left Kidney
Right Kidney
Stomach and duodenum
Left lateral
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Esophagus
Pylorus
Duodenum
Liver
Spleen
Left kidney
Right kidney
Urinary bladder
Right lateral
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Fundus
Liver
Spleen
Left kidney
Right kidney
Urinary
bladder
Normal cat abdomen
Deep circumflex iliac artery
Sometimes confused for
medial iliac lymph nodes
or ureteral calculi
Positional radiographs
• Remember gas rises
• Can manipulate the animal
Can you see the gas?
Lateral horizontal beam
Horizontal beam
• Place the animal in left lateral
– Puts the fundus of the stomach down
– Smaller pylorus is high
• Gas accumulates near the diaphragm
Some incidential findings
• Lucency on the ventral aspect of L3-4
• Cholesterol granulomas
• Spondylosis deformans
Lack of ventral aspect of L4
• It is where the diaphragm attaches
Cholesterol granuloma
• Generally in cats
Smooth bridging bone
Spaces of the abdomen
• Retroperitoneal
– Dorsal to the colon
– Contains kidneys, adrenal glands, lymph nodes
– Continuous with mediastinum
• Peritoneal
– Surrounds visceral organs
– Generally a potential space
Can compare spaces
Retroperitoneal space
Good detail
Peritoneal space
Poor detail
Loss of serosal detail
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Poor radiographic technique
Fat content of a puppy or kitten
Peritoneal fluid (many types)
Carcinomatosis
Lack of fat
Peritonitis
Peritoneal fluid
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Soft tissue and fluid are similar opacity
Therefore lose detail in the abdomen
Ultrasound superior for peritoneal fluid
Emaciation and fluid cause similar
appearance, except for overall size of
abdomen
Peritoneal fluid
• Multiple causes
– Increased hydrostatic pressure
– Decreased plasma colloid oncotic pressure
– Capillary permeability
• Radiographs very insensitive for detecting
• Cannot tell fluid type from radiographs
Mild
Severe
Severe
Lack of fat cause loss of detail
Is there peritoneal fluid?
Retroperitoneal space
• Only thing that is dorsal to the colon
Don’t forget that other view
Abdominal lymph nodes
• Many lymph nodes in abdomen
• Generally not seen radiographically
– Even if large
• Medial iliac lymph nodes are the exception
• Ultrasound more useful for lymph nodes
Medial iliac lymph nodes
Don’t forget about goats
• Can help diagnose caseous lymphadenitis
Pneumoretropertioneum
• Retroperitoneum communicates with the
mediastinum
• Therefore usually associated with:
– Subcutaneous emphysema
– Pneumomediastinum
Need large volume of gas
• Ruptured trachea
• Ruptured esophagus
– Need aerophagia
Pneumoretroperitoneum
• Not generally clinically important
• Just a sign of another disease
Even in the cow!
Pneumoperitoneum
• Can persist 10-14 days after surgery
• Rupture of a hollow viscus
– Gastrointestinal perforation
– Surgical emergency!!
• External puncture wound
Several places to look
What about large animal?
Foals and calves
• Can image abdomen
– Usually standing
– See fluid layers
• Can do barium enemas
– Strictures or atresia ani
Ileus
Traumatic reticuloperitonitis
Traumatic reticuloperitonitis
All about the belly in 1 hour!
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Good general overview
Over the next 3 weeks will be focused
Radiographs are a good overview
Helpful even if large animal
Questions?