Bladder and urethra

Question 1

What is the role of imaging modalities in bladder pathology investigation?

Answer 1

To investigate different types of bladder pathology or clinical scenarios like haematuria and trauma

Imaging modalities include plain radiography, contrast studies, compression study, and ultrasound.

Question 2

What are the imaging modalities used for bladder pathology?

Answer 2

• Plain radiographs
• Ultrasound (US)
• Contrast studies (Cystograms)

Question 3

What is the primary limitation of plain radiographs in bladder pathology?

Answer 3

Most bladder pathology is not detected on radiographs.

Question 4

What is the advantage of ultrasound in bladder imaging?

Answer 4

Easy to perform and detects all bladder pathology except bladder rupture.

Question 5

Name the different types of bladder pathology

Answer 5

*Cystitis
*Calculi (urolithiasis)
*Neoplasia
*Rupture
*Obstruction

Question 6

Which imaging modality is preferred for diagnosing cystitis?

Answer 6

Ultrasound (US) + US guided cystocentesis for culture.

Question 7

What imaging findings are associated with cystitis in dogs?

Answer 7

• Often normal on radiographs
• Thickened bladder wall on US
• Sediment (sludge) in urine may be seen.

Question 8

What is the imaging finding for neoplasia in the bladder?

Answer 8

• Irregular thickened wall on US
• Most urothelial cell neoplasms are in the trigone region, so always US the kidneys to check if the mass is obstructing the ureters (i.e. check for hydronephrosis)

Question 9

How is a bladder rupture diagnosed?

Answer 9

Positive contrast cystogram is the imaging modality of choice.

Question 10

What indicates a uroabdomen in abdominal fluid analysis?

Answer 10

• Creatinine concentration ratio >2:1
• Potassium concentration ratio >1.4:1.

Question 11

What are the common locations for calculi in the urinary tract?

Answer 11

• Kidneys
• Ureters
• Bladder
• Urethra.

Question 12

What is the significance of urate type calculi?

Answer 12

They are soft tissue opaque and are not seen on radiographs; commonly associated with Dalmatians or dogs with a portosystemic shunt.

Question 13

What is a double contrast cystogram?

Answer 13

A procedure where both air and positive contrast agent are instilled into the bladder.

Question 14

What is the purpose of a compression study in bladder imaging?

Answer 14

To determine if a mineral opacity is located in the bladder or in the colon (e.g. small piece of bone)

Question 15

What is the anatomy of the urethra in male dogs?

Answer 15

• Prostatic
• Membranous
• Penile.

Question 16

What are common causes of urethral obstruction in male dogs?

Answer 16

• Calculi
• Sludge material associated with idiopathic cystitis
• Trauma.

Question 17

What is the best imaging procedure to assess the urethra for rupture or obstruction?

Answer 17

Positive contrast urethrogram.

Question 18

What are the indications for performing a positive contrast retrograde urethrogram?

Answer 18

• To look for filling defects causing obstruction
• To check for extravasation indicating rupture.

Question 19

What is a common imaging finding in normal urethrograms?

Answer 19

Smooth mucosa.

Question 20

What is the limitation of ultrasound in assessing the urethra?

Answer 20

The portion within the pelvis cannot be seen due to shadowing from the bony pelvis.

Question 21

What does a filling defect in the urethra indicate?

Answer 21

The presence of an obstruction, usually calculi or neoplasia.

Question 22

What should be done to prevent air bubbles during a positive contrast retrograde urethrogram?

Answer 22

Fill the catheter with contrast prior to inserting it into the urethra.

Question 23

What are some imaging findings associated with bladder rupture?

Answer 23

• Loss of serosal detail on radiography
• Free abdominal fluid on US
• Contrast leaking into the peritoneum on positive contrast cystogram.

Question 24

What type of cystitis is most common in dogs?

Answer 24

Bacterial and the condition is much more common in female dogs

Question 25

What type of cystitis is mostly found in cats?

Answer 25

*Most commonly diopathic cystitis (sterile). Bacterial cystitis uncommon *Affects both female and male cats *Male cats can obstruct - common presentation in practice

Question 26

Can neoplasia of the bladder be seen on radiographs?

Answer 26

Not seen on Radiographs - bladder appears normal US required *Irregular thickened wall *Most urothelial cell neoplasms are in the trigone region - so always US the kidneys to check if the mass is obstructing the ureters (i.e. check for hydronephrosis)

Question 27

What is the best way to confirm neplasia diagnosis?

Answer 27

* US guided catheter biopsy is safest and most diagnostic * FNA - often low yield of cells and not diagnostic and risk needle track seeding

Question 28

What can cause urine in the peritoneum?

Answer 28

Urine in the peritoneum can be caused by rupture of the bladder, proximal urethra (e.g. junction with the bladder) or distal ureters (at junction with the bladder)

Question 29

What are the radiographic findings of a ruptured bladder?

Answer 29

Loss of serosal detail due to free abdominal fluid * The urinary bladder appears empty (there can be a small defect that allows the bladder to fill with a slow leak)

Question 30

Can bladder ruptue be diagnosed on US?

Answer 30

Rupture cannot be confirmed on US It looks the same as an empty bladder

Question 31

Where can urolithasis occur?

Answer 31

Can be in the kidneys, ureters (from the kidneys), bladder, or urethra Can cause obstruction in the narrow parts of the urinary tract - ureter, urethra

Question 32

What is the best modality for diagnosis of calculi? What is a common secondary disease and how is it diagnosed?

Answer 32

All calculi are seen on US so this is the best modality Be careful to examine all of the bladder, otherwise small calculi can be missed Secondary cystitis is very common so culture urine - often causes thickened bladder wall

Question 33

When should you use a double contrast cystogram?

Answer 33

In the rare situation that calculi are not seen on radiographs, and US is not available, then a contrast study needs to be performed.