Introduction to Abdominal Introduction to Abdominal RadiologyRadiology

Meghan Woodland, DVM

IndicationsIndications

• Vomiting/Diarrhea• Abdominal Pain• Hematuria• Abdominal Mass/Distension• Tenesmus (Pain on Defecation)

Technical FactorsTechnical 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

PositioningPositioning

• 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 Interpretation of Abdominal RadiographsRadiographs

• Liver• Spleen• Kidneys• GIT (Stomach, SI, Cecum, LI)• Bladder• Prostate• Extra-abdominal structures

Structures Not Normally SeenStructures Not Normally Seen

• Gall bladder• Pancreas• Adrenals• Ovaries• Uterus• Ureters• Lymph Nodes• Mesentery• Vasculature

LiverLiver

• 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

SpleenSpleen

• 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

KidneysKidneys

• 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 TractGastrointestinal Tract

• Stomach– Caudal to liver– Gastric Axis– Less than 3 ICS wide on lateral view– VD:

• Dog = U-shaped• Cat = J-shaped

Dog – VD View

“U-Shaped” Stomach

Cat – VD View

“J-Shaped” Stomach

Gastrointestinal TractGastrointestinal 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 TractGastrointestinal 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

Contrast Study

Transverse Colon

Ascending Colon

Descending colon

BladderBladder

• Size varies• Dog:

– Oval to ellipsoid– Caudal abdomen or pelvic

• Cat:– Ellipsoid– Always intra-abdominal (elongated bladder neck)

Dog – Lateral View

Bladder more pelvic

Cat – Lateral View

Long Bladder Neck

ProstateProstate

• 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 StructuresExtra-Abdominal Structures

• Soft Tissues• Bone (Spine, Pelvis, Hind limbs)• Diaphragm• Thorax (if visible)

Decreased Abdominal DetailDecreased Abdominal Detail

• Inability to distinguish organs• Causes:

– Young Animals *– Emaciated Animals– Peritoneal Fluid– Inflammation (Peritonitis, Pancreatitis)– Carcinomatosis

Normal finding

Emaciated Cat

Abdominal Fluid

How Many Babies?

Fun SlidesFun Slides

Where is the foreign body?

What organs are mineralized?

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THE END!THE END!