A bladder scan is a medical test that uses sound waves to create a real-time image of the bladder and measure the amount of urine inside it. This technology utilizes a small, handheld ultrasound device that is completely non-invasive, requiring no needles, radiation, or internal instruments. It is a painless and quick method to determine the volume of fluid within the bladder. The portable nature of the device allows for rapid assessment right at the patient’s bedside or in an examination room.
Why a Bladder Scan is Needed
The primary purpose of a bladder scan is to measure the Post-Void Residual (PVR) volume, which is the amount of urine left in the bladder immediately after emptying. Measuring PVR is an important diagnostic step when a woman experiences symptoms suggesting incomplete bladder emptying, also known as urinary retention. This condition can be caused by various issues, including a weak bladder muscle or an obstruction in the urinary tract. The scan is a valuable tool for investigating frequent urinary tract infections (UTIs) because retained urine can become a breeding ground for bacteria. By accurately quantifying the PVR volume, healthcare providers gain specific data to help guide treatment decisions for conditions like urinary incontinence or an overactive bladder, often avoiding more invasive procedures like catheterization.
Settings Where Bladder Scans Are Performed
Since the bladder scanner is a portable device, the test can be performed in a wide variety of medical settings, including primary care physician’s offices or general internal medicine clinics. The scan is also standard in urgent care centers and hospital emergency departments, where a quick assessment of bladder volume is often needed. The test is common in specialized settings, such as urology and gynecology clinics, which focus on female pelvic health. In a hospital environment, nurses frequently use the scanner on inpatient floors and in post-surgical recovery units to monitor for urinary retention, which can occur after anesthesia or pelvic procedures. Trained personnel, usually nurses or medical technicians, administer the scan right in the examination room or at the bedside, rather than requiring a visit to an imaging department.
The Simple Steps of the Procedure
The bladder scan procedure is simple and requires minimal preparation, usually involving only an instruction to empty the bladder immediately before the measurement. The patient lies comfortably on her back (supine position) on an examination table or bed. Ultrasound gel is applied to the skin of the lower abdomen, just above the pubic bone, to help the sound waves travel effectively. The technician places the handheld probe onto the gel and moves it gently to locate the bladder. For female patients, the scanner is specifically set to the “female” setting to account for the presence of the uterus and other pelvic organs, and the entire process is typically completed in just a few minutes.
Understanding the Results
The result of the bladder scan is a numerical value, measured in milliliters (mL), representing the PVR volume—the amount of urine left in the bladder after voiding. This immediate result provides the medical team with specific data on bladder function. A PVR volume is considered normal if it is less than 50 to 100 mL in healthy adults, indicating efficient emptying. While a value up to 200 mL may sometimes be acceptable depending on the patient’s age and overall health, PVR volumes consistently greater than 200 mL are considered abnormal. This is a strong indicator of inadequate emptying, which may necessitate further investigation or treatment. The healthcare provider interprets the PVR number alongside the patient’s symptoms and medical history to determine the next steps.