Abdominal Imaging I

Should abdominal rads be taken on peak inspiration or expiration?

Expiration

Abdominal margins that should be included in every rad

- diaphragmatic crura (and whole diaphragm)

- ventral body wall

- coxofemoral joints

- lumbar vertebrae

What is detail?

How well the margin of an organ or structure can be discerned from the adjacent organ/structure

AKA, ability to see organs

Ideal BCS rad detail

Adequate

Mildly to moderately obese BCS rad detail

Excellent - fat and soft tissue are different opacities

Thin/cachectic BCS rad detail

Poor - lack of fat and superimposition of organs

Why do neonates have decreased rad detail?

Higher accumulation of brown fat - higher water content

What is within the peritoneal space?

- liver

- spleen

- GI tract

- urinary bladder

- LNs

- mesentery

What is within the retroperitoneal space?

- kidneys

- perirenal fat

- ureters

- adrenal glands

- abdominal aorta

- abdominal vena cava

- +/- ovaries

- +/- prostate

Causes of decreased detail

- young animal

- decreased BCS

- peritoneal effusion

- large masses

- steatitis/peritonitis

- carcinomatosis/sarcomatosis

Cause of increased detail

- gas in peritoneal space/retroperitoneal cavity

- obesity

Causes of pneumoperitoneum

- hollow viscous rupture/GI perforation

- penetrating abdominal wound

- iatrogenic (procedure within 28 days)

- abscess rupture (gas forming bacteria)

- perforated emphysematous cystisis/cholecystitis

Where are the best places to look for pneumoperitoneum?

In front of the liver and around the falciform fat - stay away from SI

Generally, what is the cause of pneumoretroperitoneum?

Extension of pneumomediastinum

Further evaluation of pneumoperitoneum diagnosis technique

Horizontal beam rad - put patient in left lateral recumbency for 10 min prior to shooting the rad

Causes of peritoneal mineralization

- bate's body (nodular fat necrosis)

- dystrophic mineralization of a structure to prior mineralization

- vessel mineralization (endocrinopathies)

- incidental adrenal mineralization in older cats

Causes for generalized hepatomegaly

- metabolic hepatopathy (hepatic lipidosis, cushings, diabetes)

- toxicity

- viral/inflammatory hepatitis

- infiltrative neoplasia (lymphoma)

- congestion

Causes for focal hepatomegaly

- nodular hyperplasia

- neoplastic mass

- cyst

- abscess

- hematoma

- hepatic lobe torsion

Rad findings of generalized hepatomegaly

- rounded caudoventral margins

- caudally shifted gastric acid

- caudal margins extends beyond costal arches

Rad findings of focal hepatomegaly

- focally rounded margin

- asymmetry on ventrodorsal projection

- mass can be pedunculated and caudal to stomach

Rad findings of microhepatia

- caudoventral margin difficult to visualize

- cranially displaced gastric axis

- cranial displacement of other abdominal organs

2 common differentials for microhepatia

- normal variation

- chronic hepatitis with hepatic cirrhosis

- congenital PSS

2 spots of gas accumulation in the liver

- portal vein gas

- parenchymal gas

Where is the spleen found on VD rads?

Head is found left cranial

Causes of generalized splenomegaly

- breed related

- drug induced congestion (anesthesia, sedation)

- infiltrative neoplasia (lymphoma, MCT)

- extramedullary hematopoiesis

- splenic torsion

- infectious disease

Breed related generalized splenomegaly

- greyhounds

- shepherds

Causes of focal splenomegaly

- malignant neoplasia (hemang, histiocytic sarcoma, MCT)

- hematoma

- benign neoplasia/nodular hyperplasia

- abscess (rare)

Radiographic findings of pancreatitis

- cranial abdominal mass effect

- widening of the pyloroduodenal angle

- reduced detail in the right cranial abdomen

- gastric and duodenal functional ileus

Common pancreatic neoplasias

- carcinoma

- insulinoma2

Diagnosis?

Liver parenchymal gas - hepatic abscess

Diagnosis?

Hepatosplenomegaly - high suspicion for lymphoma

Diagnosis?

Generalized splenomegaly

Diagnosis?

Pneumoretroperitoneum

Diagnosis?

Generalized hepatomegaly

Diagnosis?

Focal splenomegaly

What is this and what is the significance?

Bate's body/nodular fat necrosis

- incidental

- common in cats

Diagnosis?

Pneumoperitoneum

Diagnosis?

Portal vein gas

Diagnosis?

Focal hepatomegaly