A urinary bladder ultrasound is a common, non-invasive imaging technique that uses high-frequency sound waves to create images of the bladder. This procedure helps medical professionals visualize the bladder’s structure and function without radiation exposure. Sound waves are transmitted into the body, bouncing off tissues and fluids to create a real-time picture on a monitor.
Reasons for a Bladder Ultrasound
Doctors frequently order a bladder ultrasound to investigate various urinary symptoms and conditions. It provides valuable information for symptoms like frequent urination, difficulty with urine flow, pain during urination, urinary leaking, or sudden urges.
The ultrasound is particularly useful for identifying underlying causes of recurrent urinary tract infections (UTIs) or the presence of blood in the urine, known as hematuria. It can help visualize structural problems within the bladder, such as blockages, and evaluate the bladder’s size and wall thickness.
Beyond symptom investigation, a bladder ultrasound helps determine how much urine the bladder holds when full and whether it empties completely after urination. This assessment is particularly helpful in cases of suspected urinary retention, where the bladder struggles to empty fully. The images can reveal unusual contents like bladder stones, growths, or masses.
Preparing for and What to Expect During the Procedure
Preparation for a bladder ultrasound involves ensuring the bladder is full for clearer images and a better view of the organ. Patients are usually asked to drink approximately 32 ounces (about 1 liter) of water or apple juice roughly one hour before their appointment. It is important to avoid emptying the bladder until the initial part of the examination is complete.
Once at the clinic, you may be asked to change into a hospital gown, though often comfortable clothing that allows easy access to the lower abdomen is sufficient. You will then lie on your back on an examination table. A clear, water-based gel will be applied to your lower abdomen, typically between your belly button and pubic bone. This gel helps the sound waves travel effectively from the transducer to your bladder.
A sonographer or ultrasound technician gently presses a handheld transducer onto the gel-covered area, moving it across your skin. You may feel mild pressure as images are captured from different angles. The procedure is generally painless and takes 10 to 30 minutes.
During the scan, the technician may ask you to hold your breath briefly or adjust your position for better views. After initial images of your full bladder, you will be asked to empty your bladder. The technician then performs a second scan to measure any remaining urine, known as post-void residual volume. Following the procedure, the gel will be wiped off your skin.
Interpreting Bladder Ultrasound Findings
After the ultrasound, a radiologist, a medical doctor specializing in interpreting medical images, reviews and interprets the captured images. The radiologist then compiles a report for your referring physician, who will discuss the findings with you. The interpretation considers the bladder’s appearance and function.
One common finding is bladder stones, which appear as bright, reflective structures within the bladder. These hardened mineral deposits are typically mobile and shift with changes in patient position. Bladder wall thickness is another important aspect; an abnormally thickened wall can suggest chronic inflammation, infection, or an obstruction that impedes urine flow.
The ultrasound can also detect bladder tumors or masses, appearing as abnormal growths on the bladder lining or within its muscle layer. While the ultrasound indicates their presence and location, further tests are often needed to determine their exact nature. The scan can also identify bladder diverticuli, which are abnormal pouches protruding from the bladder wall.
A significant measurement obtained is the post-void residual (PVR) volume, which indicates the amount of urine left in the bladder after urination. A PVR volume less than 50 mL is generally considered normal for adults, while volumes between 50 and 100 mL may be acceptable for older adults. A PVR volume greater than 200 mL is often considered abnormal and may suggest incomplete bladder emptying or a bladder outlet obstruction. These findings help guide subsequent steps, which may include additional diagnostic tests, medication, or other treatment strategies tailored to the individual’s condition.