Retroperitoneal Space and Upper Urinary

Question 1

the space between the peritoneum (serosa) and the dorsal body wall

Answer 1

peritoneal space

organs partly covered by peritoneum are retroperitoneal

Question 2

Most abdominal organs are fully covered by

Answer 2

peritoneum (serosa)

Question 3

between the peritoneum and usually has a tiny amount of fluid

Answer 3

peritoneum space

Question 4

What are the structures within the retroperitoneal space

Answer 4

1) Kidneys
2) Ureters
3) Adrenal glands
4) Aorta
5) Caudal Vena Cava
6) Some lymph nodes

Question 5

fluid within the retroperitoneal space

Answer 5

Retroperitoneal effusion

Question 6

What does retroperitoneal effusion look like on radiographs?

Answer 6

1) Focal/ Wispy if small amount of diffusion
2) Loss of distinction of hypaxial muscles, vessels and kidneys
*With no distinction from fluid, you cant tell if there is also a soft tissue mass
3) If large volume, expansion of retroperitoneal space, ventrally displaces GI tract

Question 7

Fluid within the retroperitoneal space is ____________ opacity and will

Answer 7

soft tissue opacity and will border efface with retroperitoneal soft tissues

normally there is contrast because of the presence of fat

Question 8

Why is there normally contrast within the retroperitoneal space

Answer 8

presence of fat

Question 9

Why might you only see retroperitoneal effusion

Answer 9

because it is separated from the peritoneal space

Question 10

What causes retroperitoneal effusion

Answer 10

1) Hemorrhage- trauma, coagulopathy, neoplasia
2) Urine leakage- kidneys, ureters, urethra (some portions)
3) AKI
4) Foreign body abscesses- grass awns into the hypaxial muscles

Question 11

What occurs with large volume of retroperitoneal effusion

Answer 11

expansion of retroperitoneal space, ventrally displaces GI tract

Question 12

What causes increased visibility of the retroperitoneal structures (opposite of fluid)

Answer 12

Retroperitoneal gas

rarely can gas also arise from retroperitoneal disease

Question 13

The retroperitoneal space is a cranial connection to

Answer 13

mediastinum of the thorax and caudal connection to intrapelvic region

rarely can gas also arise from retroperitoneal disease

Question 14

What is located cranial-dorsal-medial to kidneys

Answer 14

adrenal glands

Question 15

T/F: Mineralization of the adrenal glands in cats is significant

Answer 15

False

Question 16

What might mineralization or mass of the adrenal glands in dogs indicate

Answer 16

1) Benign adenoma
2) Primarily malignant neoplasia (pheochromocytoma or adenocarcinoma)
3) Other neoplastic (endocrine) metabolic causes

Question 17

T/F: adrenal glands are rarely seen on radiographs

Answer 17

true

Question 18

Is the left or right kidney more cranial?

Answer 18

right

Question 19

Is the left or right kidney more caudal

Answer 19

left

Question 20

How does fasting affect the visualization of the kidneys?

Answer 20

it enhances it. food or fecal material can sometimes block the kidneys

Question 21

If is commonly hard to see the ______ kidney on VD

Answer 21

right

but it is sometimes hard to see left kidney on VD

Question 22

If you have good visibility and cant see a kidney, what may indicate if it is small/absent

Answer 22

prior nephrectomy
renal aplasia (congenital)

Question 23

Dogs have kidneys that are shaped ___________
while cats have _________

Answer 23

dogs- more elongated
cats- slightly rounder

Question 24

Size of kidneys on radiographs is best evaluated when the patient is in what position

Answer 24

VD

lateral is subjective evaluation based on experience

Question 25

How do you tell the size of the kidney

Answer 25

Divide kidney length by length of L2 Dogs: 2.5-3.5x length of L2 Cats: 2.5-3.5x length of L2 older cats can be down to 2x length L2 Not strict limits

Question 26

What is normal length of kidney on VD

Answer 26

Dogs: 2.5-3.5x length of L2 Cats: 2.5-3.5x length of L2

Question 27

What determines enlarged kidney in dog

Answer 27

>3.5x length of L2

Question 28

What determines the enlarged kidney in cat

Answer 28

>3x length of L2

Question 29

marked dilation of the renal pelvis, sometimes used to imply ureter obstruction

Answer 29

hydronephrosis

Question 30

lesser dilation of renal pelvis, less likely affect kidney radiographic size

Answer 30

pyelactasia

Question 31

enlargement compensating for loss of function of opposite kidney, contralateral kidney often (not always) small

Answer 31

compensatory hypertrophy

Question 32

common degenerative change to kidneys, and can uncommonly get disturbingly large

Answer 32

renal cysts

Question 33

fluid between the kidney cortex and capsule, various causes

Answer 33

perinephric pseudocyst

Question 34

many cysts in kidneys, especially in some breeds like persian cats, Himalayan cats, cairn terriers, bull terriers

Answer 34

Polycystic kidney disease

Question 35

amyloid deposition in kidneys, especially in some breeds

Answer 35

amyloidosis

Question 36

What cause bilateral enlarged kidneys

Answer 36

1) Renal lymphoma (cats) 2) FIP (cats) 3) Hydronephrosis often mildly enlarged 1) AKI 2) Congential portosystemic shunt Metastatic neoplasia Polycystic disease

Question 37

What causes unilateral kidney enlargement

Answer 37

1) Hydronephrosis often muldly or relatively enlarged 1) Compensatory hypertrophy often with abnormal shape 1) Primary renal tumor 2) Renal cysts 3) Metastatic neoplasia

Question 38

What measurements dictate small kidney(s)

Answer 38

Dogs <2.5x L2 Cats <2.5 or <2x L2

Question 39

What could cause bilateral small kidneys

Answer 39

Chronic renal degeneration Renal dysplasia/hypoplasia (young)

Question 40

What could cause unilateral small kidney

Answer 40

Chronic renal regeneration atrophy secondary to chronic obstruction renal dysplasia/hypoplasia (more often bilateral)

Question 41

What could cause kidneys to be irregular shape but not small

Answer 41

infarcts or other mild chronic renal degeneration

Question 42

What could cause changes in kidney opacity

Answer 42

1) Nephroliths- if in region of renal pelvis 2) Focal dystrophic mineralization in cortex

Question 43

Where in the kidneys do nephrliths occur

Answer 43

renal pelvis

Question 44

Where in the kidneys does focal dystrophic mineralization occur

Answer 44

renal cortex

Question 45

T/F: ureters are visible in on rads

Answer 45

False- not typically but you can use positive iodinated contrast agen (often iohexol) to see rads, fluoroscopy, or CT

Question 46

Where do ureteroliths typically occur on rads

Answer 46

small mineral objects in the retroperitoneal space between the renal pelvis and urinary bladder

Question 47

Urteroliths are more common in cats or dogs

Answer 47

cats

Question 48

What might trick you into seeing uteroliths

Answer 48

the deep circumflex iliac artery/vein seen end on due to summating with itself, soft tissue stacked in the direction of beam will appear mineral opaque also end-on bowel

Question 49

What should you do to confirm uteroliths

Answer 49

ultrasound

Question 50

IV injection of iodinated contrast medium what when filtered by kindeys, contrast opacifies kidneys, ureters, and urinary bladder

Answer 50

Excretory Urography

Question 51

Technique where contrast is injected into the renal pelvis difficult to do

Answer 51

Pyelogram

Question 52

T/F ultrasound is usually better than radiographs at evaluating upper urinary system

Answer 52

True

Question 53

T/F: CT give more info about the upper urinary system than ultrasound

Answer 53

True- but it is really expensive IV contrast generally required for abdomen CT but may cause issues with severe kidney disease CT is good for ectopic ureters and masses