Kidney and Bladder Ultrasound: What It Shows and How to Read the Report

Kidney and bladder ultrasound is an examination in which images of internal organs are obtained using sound waves. A referral is given for symptoms, such as pain, or to monitor a known condition. Below are the definition of the method, what it shows, the preparation procedure, and an explanation of typical report wording.

1. What kidney and bladder ultrasound is

Ultrasound (ultrasonography) is an imaging method in which pictures of internal organs are built using sound waves. The waves used are safe, and ionizing radiation is not used — unlike X-ray and computed tomography.

The kidneys are two fist-sized organs on either side of the spine above the lower back. They filter and cleanse the blood, remove metabolic products, and produce urine. Their image allows the size and shape of the organ to be seen and unusual changes to be detected.

The scan is ordered to investigate complaints (pain, a palpable mass), to monitor a known condition, and so that the specialist can see the structure of the organ during the procedure. The result is sent to the doctor who issued the referral.

2. What can be seen on a kidney ultrasound

Ultrasound shows the size and shape of the kidneys and helps check for unusual changes. It is one of the imaging examinations of the kidneys, along with blood and urine tests.

Early kidney disease usually has no signs or symptoms, and examination is the only way to find out how the kidneys are working. Testing is needed in the presence of key risk factors: diabetes, high blood pressure, heart disease, and a family history of kidney failure.

Ultrasound does not replace functional tests. Glomerular filtration rate (GFR) shows how well the kidneys filter blood. Blood and urine tests for creatinine determine the level of the metabolic product that the kidneys remove; a urine albumin test detects protein that enters the urine when the organ is damaged. A kidney biopsy — examination of a small tissue sample under a microscope — establishes the cause of the disease and the degree of damage.

3. How the examination is performed and how to prepare for it

The preparation procedure is communicated by the facility where the scan is performed. Typical requirements are as follows:

• drink several glasses of water shortly before the procedure and refrain from going to the toilet so that the bladder remains full;
• remove jewelry and piercings from the scan area;
• if necessary, change into a hospital gown behind a screen;
• if desired, ask that a companion be present in the room.

The procedure lasts approximately 10 to 45 minutes, sometimes longer. The transducer is moved over the skin, which is covered with gel. The patient has the right to stop the procedure at any moment. Pain is reported to the staff member performing the scan.

4. How to read a kidney ultrasound report

The report describes the size and shape of the kidneys and the presence of unusual changes. The conclusion is formulated by the doctor taking into account complaints and data from other examinations.

Unclear wording, including descriptions of changes in the kidney tissue (parenchyma), is explained by the doctor who referred for the examination. The result is given at the end of the appointment or communicated after several weeks — the timeframe depends on the reason for the scan; if there is no response within several weeks, it is inquired about from the specialist who issued the referral.

5. When additional examinations and a doctor's consultation are needed

Ultrasound is part of a comprehensive kidney check, not the only test. Depending on the reason for the examination, blood and urine tests, GFR assessment, an albumin test, and in some cases a kidney biopsy may be needed. The set of examinations is determined by the doctor.

Kidney and bladder ultrasound alone is not a reason to call an ambulance. The numbers 103 and 112 are used for life-threatening conditions — for example, suspected stroke or heart attack, or severe trauma.

If the result is unclear or there are questions about it, one should consult the doctor who referred for the examination.

This material is for reference purposes: the ultrasound report is interpreted by a doctor, and the article does not replace a consultation.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer