Retroperitoneal Space and Upper Urinary Tract

Question 1

Define: Peritoneal Space

Answer 1

Between peritoneum and usually has a tiny amount of fluid

Question 2

Define: Retroperitoneal Space

Answer 2

Between peritoneaum and dorsal abdominal body wall
Organs partly covered by peritoneum are retroperitoneal

Question 3

What (6) organs/structures are considered retroperitoneal structures?

Answer 3

Kidneys
Ureters
Adrenal glands
Aorta
Caudal vena cava
Some lymph nodes

Question 4

What does retroperitoneal effusion look like on radiographs?

Answer 4

Loss of distinction of hypaxial muscles, vessels, kidneys
With loss of distinction, you can’t tell if there is also a soft tissue mass
Large volume = ventrally displaced GI tract

Question 5

Answer 5

Retroperitoneal effusion

Question 6

Answer 6

Retroperitoneal effusion

Question 7

Answer 7

Peritoneal effusion (normal retroperitoneal space)

Question 8

What are important causes of retroperitoneal effusion?

Answer 8

Hemorrhage: trauma, coagulopathy (rodenticide), neoplasia
Urine leakage: kidneys, ureters, urethra (some portions)
AKI
FB abscesses (grass awns, esp. foxtails)

Question 9

Answer 9

Retroperitoneal effusion
Animal attach trauma

Question 10

Answer 10

Retroperitoneal effusion
Animal attack trauma

Question 11

Answer 11

Retroperitoneal effusion
Dog attack trauma

Question 12

Answer 12

Retroperitoneal effusion (hemorrhage)
HBC

Question 13

Answer 13

Retroperitoneal effusion (hemorrhage)
HBC

Question 14

Answer 14

Retroperitoneal effusion

Question 15

Answer 15

Retroperitoneal effusion

Question 16

Answer 16

Retroperitoneal effusion

Question 17

Answer 17

Mild retroperitoneal effusion
Trace peritoneal effusion
Large urinary bladder (obstruction)

Question 18

What is indicative of adrenal gland mineralization in dogs and cats?

Answer 18

Cats: not significant
Dogs: benign adenoma or primary malignant neoplasia

Question 19

Which kidney is which?

Answer 19

Question 20

Answer 20

Normal kidneys

Question 21

Answer 21

Normal kidneys

Question 22

Answer 22

Normal kidneys

Question 23

Answer 23

Normal kidneys

Question 24

Answer 24

Normal kidneys

Question 25

How do we measure kidney size in relation to normal?

Answer 25

Question 26

What are (7) differentials for bilateral kidney enlargement?

Answer 26

Renal lymphoma (cats) FIP (cats) Hydronephrosis AKI (mild) Congenital PSS (mild) Metastatic neoplasia Polycystic kidney disease

Question 27

What are (5) differentials for unilateral kidney enlargement?

Answer 27

Hydronephrosis Compensatory hypertrophy (mild) Primary renal tumor (abnormal shape) Renal cysts (abnormal shape) Metastatic neoplasia (abnormal shape)

Question 28

Answer 28

Bilateral mild renomegaly *FIP*

Question 29

Answer 29

Bilateral mild renomegaly *FIP*

Question 30

Answer 30

Right renomegaly (left upper end of normal) Both kidneys irregular Abdominal mass (labeled) *Lymphoma*

Question 31

Answer 31

Right renomegaly (left upper end of normal) Both kidneys irregular *Lymphoma*

Question 32

Answer 32

Bilateral renomegaly

Question 33

Answer 33

Bilateral renomegaly

Question 34

Answer 34

Bilateral mild renomegaly *Presumed AKI*

Question 35

Answer 35

Bilateral mild renomegaly *Bilateral hydronephrosis due to obstructive ureteroliths*

Question 36

Answer 36

Mild left renomegaly *Hydronephrosis due to retrocaval ureter*

Question 37

Answer 37

Enlarged left kidney *Hydronephrosis*

Question 38

Answer 38

Irregular shape and enlargement of left kidney *Renal carcinoma*

Question 39

Answer 39

Left renomegaly with soft tissue opaque material in caudal left peritoneal space *Primary renal neoplasia with hemorrhage*

Question 40

Answer 40

Large left kidney mass *Sarcoma*

Question 41

Answer 41

Mild left renomegaly with nephrolith *Compensatory hypertrophy of left kidney and marked chronic degenerative change of right*

Question 42

What are (2) differentials for bilateral small kidneys?

Answer 42

Chronic renal degeneration Renal dysplasia/hypoplasia

Question 43

What are (3) differentials for unilateral small kidneys?

Answer 43

Chronic renal degeneration Atrophy secondary to chronic obstruction Renal dysplasia/hypoplasia (more often bilateral)

Question 44

What values are considered small vs enlarged kidneys?

Answer 44

*Dogs* Small < 2.5x L2 Large >3.5x L2 *Cats* Small < 2x L2 Large > 3x L2

Question 45

Answer 45

Small left kidney *Degenerative renal change or dysplasia/hypoplasia*

Question 46

Answer 46

Small kidney, tiny nephroliths *Degenerative renal change or dysplasia/hypoplasia*

Question 47

Answer 47

Left kidney bigger than right *Chronic right renal obstruction with hydronephrosis and compensatory hypertrophy of left*

Question 48

What causes mineralization in the kidneys?

Answer 48

Nephroliths (if in region of renal pelvis) Focal dystrophic mineralization

Question 49

Answer 49

Ureteroliths

Question 50

Answer 50

Ureteroliths

Question 51

Answer 51

Bilateral renomegaly (borderline) *Bilateral obstructive ureteroliths and hydronephrosis*

Question 52

Answer 52

Bilateral renomegaly (borderline) *Bilateral obstructive ureteroliths and hydronephrosis*