Ultrasound of the kidneys and bladder

What it can help assess

A urinary ultrasound can show the size and shape of the kidneys, swelling caused by a blockage, many stones, and how much urine remains in the bladder after urinating. It is often used before or alongside other tests.

Why it may be ordered

It may be ordered for flank pain, blood in the urine, suspected stones, recurrent infections, or difficulty emptying the bladder. Because it avoids radiation, it is often chosen first and is frequently used in pregnancy and in children.

Preparation

Preparation is usually simple. For a bladder scan you may be asked to arrive with a comfortably full bladder. The team will give any specific instructions.

What happens

You lie down while a technician moves a small handheld probe with gel over the skin. The scan is painless and usually takes a short time. Images are reviewed by a radiologist.

Limitations

Ultrasound does not show every stone or problem, so a normal scan does not rule out all conditions. A clinician may recommend further imaging, such as a CT scan, depending on the situation.

Questions to ask a clinician

• What is the ultrasound looking for in my case?
• Do I need a full bladder or any other preparation?
• Could I need further imaging afterwards?
• How will the results change my care?