Urinary

Question 1

What anatomic regions does the cranial pole of the left kidney contact?

Answer 1

It contacts the greater curvature of the stomach and dorsomedial aspect of the spleen laterally.

Question 2

Is the spleen dorsal or ventral to the left kidney.

Answer 2

Often ventral

Question 3

Where is the right kidney found?

Answer 3

In the renal fossa of the right caudate liver lobe

Question 4

Where do the descending duodenum and right pancreatic lobe lie in relation to the right kidney?

Answer 4

Immediately ventral and medial to it

Question 5

Describe the anatomy of the renal arteries.

Answer 5

The renal arteries often divide into dorsal and ventral branch before reaching the kidney.

In ~20% of dogs, the renal arteries may be doubles, particularly the left renal artery.

The right renal artery arises before (~2cm cranial) the left renal artery.

Question 6

Where do the renal veins lie in relation to the renal arteries?

Answer 6

They lie immediately ventral to their corresponding arteries.

Question 7

What are the three distinct zones that can be seen on ultrasound of the kidneys?

Answer 7

Renal cortex
Renal medulla
Renal sinus - renal hilum opens to the renal sinus

Question 8

Why is the renal sinus more hyper echoic than the renal cortex?

Answer 8

Because of peripelvic fat - appearing as a v-shaped hyeprehcoic region

Question 9

What causes increased echogenicity of the renal cortex in cats?

Answer 9

Fat vacuoles in the cortical tubular epithelium

More common in older male cats

Question 10

For dogs, what is the suggested normal range for kidney length: aortic diameter ratio?

• There is high variation in kidney length of dogs with similar BW. Cats have less variation.

Answer 10

The investigators concluded that a ratio of kidney length to aortic diameter of 5.5. - 9.1 was normal.

<5.5 indicates the kidneys are small
>9.1 indicates the kidneys are large

However, this ratio is rather broad and the usefulness is yet to be established in dogs with various renal disease.

Question 11

What is range for normal kidney length in cats?

Answer 11

3.0 - 4.5 cm long is considered normal

Question 12

What are some differentials for renomegaly with smooth contours?

Answer 12

Compensatory hypertrophy
Acute renal failure
Ethelyen glycosl poisoning 
Hydronephrosis 
Acute nephritis
Early amyloidosis
PSS
Diffuse infiltrative disease
Diffuse neoplasia

Question 13

What are some differentials for renomegaly with irregular contours?

Answer 13

Granulomas
Abscess
Polycystic kidney disease
Neoplasia (primary or metastatic)

Question 14

What are differentials for small kidneys?

Answer 14

Congenital renal hypoplasia or dysplasia

End-stage renal disease

Question 15

What happens to the kidneys when furosemide or contrast agents are administered?

Answer 15

Diuresis associated with administration of furosemide produces a transient increase in kidney size due to medullary enlargement in normal dogs.

Diuresis associated with water-soluble iodinated contrast agents during urography causes lesser degrees of transient kidney enlargement.

Question 16

What is the upper limit for renal pelvis, in a normal dog not underlying diuresis?

Answer 16

1.8 mm

Recent studies show up to 3mm in dogs

Question 17

What is normal thickness of the proximal ureter?

Answer 17

3-4 mm

Question 18

What does failure to visualize the kidney on an excretory urogram indicate?

Answer 18

Either the kidney is absent from renal genesis or prior nephrectomy
Or it is non-functional

Question 19

What are the 2 different types of renal cysts?

Answer 19

Simple cyst = round or ovoid contour, echo-free contents, smooth and sharply demarcated thin walls with a distinct far-wall border, and strong distal echo enhancement.

Complicated cysts =

Cysts are frequently seen end-stage kidney disease and might be part of the degenerative process affecting the kidneys. Can also be seen with PCKD.

**Cysts can result in displacement, distortion, and dilation of the collecting system from partial obstruction.

Question 20

How can you treat a renal cysts?

Answer 20

Solitary renal cyst have been successfully ablated with ultrasound-guided ethanol injection.

Question 21

What other differentials must be included if the renal cystic walls are thick or irregular, internal separation are present, or the contents of the cysts are not completely anechoic?

Answer 21

Complicated cysts
Hematoma
Abscess
Tumor

Question 22

What are some differentials for non-neoplastic renal masses with solid patterns?

Answer 22

Granuloma
Hematoma or abscess containing homogenous, viscous internal debris may also occasionally simulate a renal mass

**Fine needle aspiration should be performed

Question 23

Describe the sonographic appearance of complex renal masses and what each region represents.

Answer 23

Complex masses ay contain a variable mixture of anechoic, hypo echoic and hyper echoic components.

The anechoic and hypo echoic regions represent areas of hemorrhage or necrosis. Sonographers often refer these regions as cystic areas despite the fact that their appearance do not resemble a true cyst. The majority of the mass contains these “cystic” regions.

The solid portions represent a smaller %.

Hyperehcoic areas with dirty shadowing may also occur if gas-producing organs are present.

Question 24

What are some differentials for complex masses?

Answer 24

Hematomas
Granulomas
Abscess
Acute infarcts
Neoplasia (primary or metastatic)

Aspiration for cytologic analysis and bacterial culture may be required for definitive diagnosis.

Question 25

What are differentials for hyeprehcoic areas in the renal cortex?

Answer 25

Renal infarct 
Renal calcification
Renal fibrosis from previous pyelonephritis 
Gas
Neoplasia

Question 26

What are differentials for overall increased cortical echogenicity?

Answer 26

Glomerular or interstitial nephritis
Pyelonephritis
Leptospirosis
Acute tubular necrosis 
Ethylene glycol toxicosis 
End stage renal disease 
Nephrocalcinosis

Question 27

In dogs with hypercalcemia what causes a medullary rim sign?

Answer 27

Calcification of the basement membrane of the Bowman capsule and tubular epithelium of the adjacent cortex and medulla

Question 28

What are some differentials for renal pelvic dilation?

Answer 28

Diuresis
Congenital disease
Pyelonephritis
Obstruction to urine flow

If dilation is more than 3-4 mm, diuresis is considered less likely and further investigation is warranted

NOTE: the absence of dilation does not rule out disease (e.g. pyelonephritis)

Question 29

What are some differentials for dilated ureters?

Answer 29

Infection
Obstruction
Ruptured ureter
Ureterocele
Ectopic ureter

Question 30

What is a possible complication of hydronephrosis?

Answer 30

It may progress to pyonephrosis causes by urinary statis and subsequent infection. It is a collection of sloughed urothelium and inflammatory cells within a hydrfonephrotic kidney and or ureter.

Question 31

What are some possible causes of hydronephrosis?

Answer 31

In most cases, a bladder, urethral, or prostatic tumor involving the trigone is responsible for ureteral obstructions.

Obstructions due to ureteral inflammation, blood clots, fibroepithelium polyps, calculi, extrinsic masses, ureteral fibrosis, or strictures is less common.

Question 32

What are differentials for ureteral tumors?

Answer 32

Leiomyoma/leiomyosarcoma
Fibropapilloma
Transitional cell sarcoma

Question 33

What is the most common cause of ureteral obstruction in cats?

Answer 33

Ureteral calculi

Question 34

What is a urinoma?

Answer 34

A “paraureteral pseudocyst”

Urinoma is an encapsulated extravasation of urine. Urine leaked initiates a fibroblastic reaction encapsulating the urine in the retroperitoneal tissues, which may obstruct the ureter.

Urinomas have previously reported been to cause obstruction by extravasation and encapsulation of urine around a rupture ureter.

Question 35

What is the most common congenital condition that causes dilated ureters and renal pelvis dilation? Can be unilateral or bilateral.

Answer 35

Ectopic ureters

More common in females

Question 36

What is a ureterocele?

Answer 36

A congenital dilation of the distal ureter that is sometimes accompanied by an ectopic ureter or obstruction.

Question 37

Some calculi do not shadow. What sonographic techniques can be used to maximize shadowing to be obtained?

Answer 37

The highest frequency transducer possible must be used
The beam must be directed perpendicular to the suspected calculus
The calculus must be placed within the focal zone of the transducer
Doppler imaging can sometimes help identify questionable calculi of a “twinkling artifact” is seen

Question 38

What is the normal urinary bladder wall thickness in dogs and cats?

Answer 38

Dogs:

• Varies with body weight
• Normal in minimally distended bladder 2.3 mm
• Normal in moderately distended bladder 1.4 mm

Cats:
- 1.3-17 mm

Question 39

Describe the appearance of polyploid cystitis.

Answer 39

Wall thickening accompanied by multiple small masses that project into the bladder lumen. They are more common found cranioventrally within the bladder but can also be found craniodorsally.

If the mass is sessile or there is a single mass, neoplasia is most likely. Because neoplasia is more common than polyps, the diagnosis must be confirmed by biopsy.

Question 40

Describe the sonographic appearance of emphysematous cystitis.

Answer 40

Hyperechoic wall with irregular, dirty shadowing produced by the gas. This appearance can be distinguished from gas within the balder lumen because it is localized within the wall, follows. the contours closely and maintain a fixed location with positional change.

Question 41

Describe the appearance of pseudomembranous cystitis.

Answer 41

Bladder wall thickening, suspended echogenic debris, and unusual hyperemic septa diving the lumen into compartments.

Question 42

Describe the appearance of TTC.

Answer 42

Focal wall thickening with irregular, sessile mass extending into the bladder lumen.

Question 43

How can you differentiate a bladder mass from an a blood clot.

Answer 43

Blood clots tend to be mobile and settle within the dependent portion of the bladder. They also don’t have doppler waves.