Category: 4. Bladder Pathology

Bladder masses are generally echogenic, irregularly shaped, and are found either mounted on the bladder wall or in areas of irregularly increased bladder wall thickness.

The majority of bladder masses are from transitional cell carcinoma. However, other causes include bladder diverticulitis, congenital outpouching of the bladder wall, and bladder wall thickening. Any sign of a bladder mass requires further urologic evaluation, and possibly cystoscopy and further imaging.

Since blood clots can be mistaken for bladder masses, irrigation of the bladder followed by another ultrasound scan is recommended (Geertsma et al). Blood masses are often mobile so it is recommended to have the patient roll onto their sides during the follow-up scan. If a blood clot is present, it should move as the patient changes position.

Bladder stones are often seen after renal stones travel from the ureters into the bladder. Bladder stones can also form in the bladder itself due to bladder stasis in patients with chronic urinary retention (Tublin, 2001).

On ultrasound, these stones appear hyperechoic and mobile with acoustic shadowing. If the stone is stuck in the ureterovesical junction (the junction between the ureter and the bladder body), the patient may also present with unilateral hydronephrosis.

Ureteral jets are a normal and periodic efflux of urine from the ureter into the bladder. Visualization of bilateral ureteral jets rules out complete obstruction of a specific ureter with high specificity (Strehlau).

• To see ureteral jets, scan slowly through the bladder in the transverse view and focus on the trigone (located on the posterior wall of the bladder).
• Turn on color Doppler or power Doppler while scanning the bladder in the transverse view. It may take 5-10 minutes before you can visualize bilateral jets so be patient.

A urinary foley catheter drains urine from the patient’s bladder. Your patient may need a catheter if he or she has urinary incontinence, prostate problems, or is preparing for surgery. At the end of the foley catheter lies a small balloon filled cuff with water that stabilizes the catheter inside the bladder.

Ultrasound is useful for checking that the foley catheter has been inserted properly and if it is draining urine properly.

Normal findings of a foley catheter on ultrasound will show an empty bladder with an inflated cuff.

If a foley catheter is malfunctioning or clamped, you will see the foley catheter in the bladder but with a distended bladder.

Urinary Retention and Bladder Distension

Urinary retention occurs when a patient cannot completely empty their bladder. Common causes of bladder distention and/or retention include an enlarged prostate, bladder outlet obstruction, neurologic disorders, foley malfunction, or various medications.

Normal post-void residual (PVR) urine volume is <50 mL in patients, but <100 mL can be considered normal in patients older than 65 (Kelly 2004). The post-void residual volume is calculated using the ultrasound bladder volume formula described above or via urethral catheterization.

Performing a bladder ultrasound is recommended before catheterization because it is much more comfortable for the patient, less invasive, and avoids the risk of urethral trauma. Furthermore, performing an ultrasound for initial imaging to look for a distended bladder can help you evaluate if urethral catheterization will be necessary.