Ch 42 Urinary bladder Flashcards
How many ligaments (from peritoneal reflections) hold the urinary bladder in place? What are they called?
3; 1 middle and 2 lateral ligaments
What are the layers of the urinary bladder?
mucosa, submucosa, muscular, serosal/peritoneum
In which species is the urinary bladder always intraabdominal (even when empty)? why?
cats, because the urinary bladder has a long neck.
Why is there good visualisation of the urinary bladder?
Because there is fat in the bladder ligaments that hold it
What percentage of dogs with perineal hernia had urinary bladder retroflexion?
24%
Compared to continent dogs, incontinent female dogs with intrapelvic urinary bladders usually have:
shorter urethras
Are intrapelvic urinary bladders always clinical?
No, they can be a normal variant.
Significant in incontinent female dogs, and can be associated with ectopic ureters!
What can cause a urinary bladder to have a pointed apex and elongated shape?
persistent urachal ligament
What appearance will a persistent urachal ligament cause?
pointed apex and elongated shape of the urinary bladder
emphysematous cystitis in a dog with DM
iatrogenic gas in bladder
prostatomegaly (caudal structure)
urinary calculi (cranial structure)
Which condition is emphysematous cystitis associated with?
diabetes mellitus; hyperglycemia/glucosuria/glucose acts as a substrate for glucose fermenting bacteria that produce gas (e.g. e. coli, klebsiella), (as well as DM causing lower immunity and poorer circulation)
Is emphysematous cystitis always linked with diabetes mellitus?
no, can occur in non-DM patients
what are the 6 types of uroliths?
Ca oxalate
Ca phosphate
Struvite
Silica
Urate
Cystine
Which uroliths are non-radiopaque?
Urate
Cystine
Which stones are smoothly marginated?
cystine, urate
+/- struvite (usually)
+/- Ca oxalate, Ca P
Which uroliths are mod - markedly opaque?
Ca oxalate
Ca P
struvite
silica
which urolith is this?
silica
Which complication can occur from overdistension of the bladder with contrast, especially in cats? is it a clinical problem?
- intramural and submucosal accumulation of contrast
- usually not a clinical problem
what is the most serious complication from negative contrast cystography? how may it be prevented?
- gas embolization in circulation > death
- use more soluble NO or CO2 instead of room air
What is the advantage of NO or CO2 for negative contrast cystography?
more soluble than room air and therefore less likely to cause gas emboli
which positive contrast medium should never be used for cystography?
barium
which positive contrast medium should be used for cystography?
organic water-soluble iodides in 20% iodine solution
how much positive contrast medium should be used for cystography?
approx 10 ml/kg
3.5 - 13.1 ml/kg - stop if any back pressure, reflux around the catheter, or bladder feels adequately distended
Which is the least helpful to evaluate the bladder: positive, negative, or double contrast cystography?
negative
Which cystography method would be indicated for suspected rupture?
positive contrast
Which cystography method would be indicated for suspected bladder wall lesions or filling defects?
double contrast
Which cystography method would be indicated for suspected abnormal location?
positive or negative
*not negative if rupture suspected
What goes first in a double contrast study?
positive, then negative
how much positive contrast in a double contrast study?
cat: 0.5 - 1 mL
<25lb dog: 1-3 mL
>25lb dog: 3-6 mL
What is the typical location of polypoid cystitis?
Cranioventral bladder
What kind of mucosa does the bladder have?
transitional epithelium (urothelium) - specialized epithelial tissue is unique in its ability to stretch and accommodate fluctuations in volume within the urinary system.
The normal urinary bladder wall is approximately ____ thick regardless of the degree of distention
1 mm
What are 3 common causes of free (unattached) filling defects in positive con trast cystography?
air bubbles, calculi, and blood clots
what is the cobra-head sign?
ureterocoele filling with contrast medium due to communication with the bladder
Smooth luminal filling defect (black arrows) that projects into the urinary bladder neck is an ureterocele. In this patient the ureterocele is radiolucent because it does not contain contrast medium but is surrounded by contrast medium in the urinary bladder
Does contrast leakage always occur immediately with bladder tears?
usually, but if a small tear on the neck, then another radiograph after 5-10 min might be needed to diagnose
large air bubble in a mostly fluid-filled urinary bladder may produce the appearance of a thick urinary bladder wall. Here, the pseudothick wall (black arrows) is created by the interface between positive–contrast medium and gas. In this dog, the region between the arrows is more opaque than normal soft tissue because of the presence of contrast medium, and therefore this would not be confused with urinary bladder wall thickening.
A honeycomb appearance (black arrows) created by several adjacent air bubbles
causes of urine reflex or retention
- vesicoureteral reflux
- urachal anomalies (congenital or acquired diverticula, cysts, persistent patent urachus)
- traumatic urinary bladder diverticula
Which artifacts cause an erroneous display of echogenic material in the urinary bladder lumen?
Side and grating lobe artifacts, generated by the adjacent colon
Intraluminal, hyperechoic foci representing crystals (crystalluria) are present in the dependent portion of urinary bladder.
Intraluminal, hyperechoic, lacy material is acute hemorrhage located in the mid and ventral aspects of the urinary bladder. A small amount of echogenic fluid representing free abdominal hemorrhage (F) is present adjacent to the cranioventral aspect of the urinary bladder.
What are the layers of the urinary bladder and their echgenicities?
hyperechoic inner mucosa
hypoechoic middle muscle
hyperechoic outer serosa
What is a cause of echogenic urine in clinically normal cats?
lipiduria
How does acute haemorrhage behave in the urinary bladder vs. blood clots?
Blood clots tend to gravitate to the dependent aspect; acute haemorrhage may stay suspended and change little with balottement or repositioning
The amount of shadowing of a calculus is related to:
- the height of the calculus (the bigger, the more shadowing)
- the transducer frequency (the higher, the more shadowing)
How does transducer frequency affect acoustic shadowing of a calculus?
Higher frequency = more likely to produce shadowing
What can you do with the focal zone to help differentiate calculi from other structures?
Optimising the focal zone at the depth of a calculus may generate shadows
How would you use doppler to differentiate mineralised from non-mineralised sediment?
Finding a twinkling artifact allows for the strong suspicion of mineralized and rough-surfaced material.
What are the predominant factors that twinkle artifact depends on?
Size of calculus (larger, twinklier)
Roughness of calculus (rougher, twinklier)
Doppler gain setting (higher, twinklier)
Which modality is better for diagnosing congenital abnormalities of the bladder - US or contrast rads?
contrast rads
Where is polyoid cystitis usually located?
cranioventral or craniodorsal bladder
Where is bladder TCC usually located?
neck / trigone
Which wall changes can occur from chronic partial lower urinary tract obstruction?
muscular thickening
What is uterus masculinus and what are the sonographic findings?
A rare condition called uterus masculinus can be associated with chronic cystitis and an enlarged prostate gland in male dogs.74 The sonographic changes describing this condition include identification of hypoechoic tubular or cylindrical structures originating from the craniodorsal aspect of the prostate gland, adjacent to the urinary bladder.
most common bladder tumour, what does it look like on US
TCC, single or multiple, irregularly shaped, broad-based, complex to hypoechoic mass protruding into the urinary bladder lumen. The echo pattern can vary if internal fibrosis, mineralization, and necrosis have developed. Adjacent blood clots can occur.
examples of smooth muscle neoplasia and its US appearance
Smooth muscle neoplasia, such as leiomyoma or leiomyo- sarcoma, can appear as a single, round, well-defined intraluminal mass.
Which type of urinary bladder tumor is often located in the neck of the urinary bladder and typically found in young dogs?
a) Transitional cell carcinoma
b) Leiomyoma
c) Fibrosarcoma
d) Rhabdomyosarcoma
c) Fibrosarcoma
d) Rhabdomyosarcoma
What percentage of dogs with perineal hernia were noted to have retroflexion of the urinary bladder?
14%
24%
34%
44%
24%