A renal ultrasound is a non-invasive imaging technique that provides detailed views of the kidneys. It uses sound waves to create images, allowing healthcare providers to assess their size, shape, and location. This commonly performed examination is known for its safety and lack of radiation exposure.
How Renal Ultrasound Works
Renal ultrasound uses high-frequency sound waves. A small, handheld device called a transducer is placed on the skin, emitting these sound waves into the body. These waves travel through tissues and organs, including the kidneys, and then bounce back as echoes.
The transducer receives these reflected sound waves, and a connected computer processes them. The system converts the echoes into real-time images on a monitor. A water-based gel is applied to the skin to ensure optimal sound wave transmission and eliminate air pockets.
Reasons for a Renal Ultrasound
Healthcare providers often recommend a renal ultrasound for concerns about kidney function or related symptoms. Unexplained back or flank pain is a common reason, as it can indicate kidney issues. Urinary problems, such as frequent urinary tract infections, difficulty urinating, or blood in the urine, may also prompt this imaging.
Abnormal blood tests related to kidney function, like elevated creatinine levels, can suggest the kidneys are not filtering waste effectively. High blood pressure, which can impact kidney health, also warrants investigation. The procedure is also used to monitor individuals with known kidney conditions over time.
Conditions a Renal Ultrasound Can Identify
A renal ultrasound can identify various kidney-related conditions. It effectively detects kidney stones, appearing as bright, reflective objects that often cast shadows. While the stone itself may not always be visible, the ultrasound can show its effect, such as a blockage leading to urine backup.
Cysts within the kidneys are also frequently identified. Simple cysts typically appear as round, fluid-filled structures with smooth, thin walls. More complex cysts might have internal echoes or irregular features, requiring further evaluation.
Hydronephrosis, the swelling of the kidney due to urine buildup, is another finding. This condition indicates a blockage in the urinary tract, preventing urine from draining properly. The ultrasound can grade its severity, from mild dilation of the renal pelvis to severe cases where the collecting system is significantly distended.
The scan can also reveal suspicious growths, such as tumors or masses, by showing distortions in normal kidney architecture. Although ultrasound can identify these, further tests are typically necessary for a definitive diagnosis. Signs of inflammation or abscesses, indicative of kidney infections like pyelonephritis, can also be observed.
The ultrasound assesses kidney size and shape, which can indicate chronic kidney disease if the kidneys appear shrunken. Abnormalities in size or contour might also point to congenital issues. Doppler ultrasound, a specialized technique, can evaluate blood flow to and within the kidneys, helping to detect issues like renal artery stenosis.
What to Expect During the Procedure
Patients typically lie on an examination table, often on their back or side, for optimal access to the kidney area. Depending on specific instructions, some preparations, such as having a full bladder, may be required.
A healthcare professional applies a water-based gel to the skin over the abdomen or back. This gel helps the transducer glide smoothly and ensures good sound wave transmission. The transducer is then moved gently across the skin. The procedure is usually painless and often completed within 30 minutes.
Interpreting Your Renal Ultrasound Results
After the renal ultrasound, the acquired images are reviewed and interpreted by a radiologist, a medical doctor specializing in imaging. The radiologist prepares a detailed report outlining the findings, which is then sent to the healthcare provider who requested the scan.
Your referring doctor will then discuss the results with you, explaining what the images reveal and how these findings relate to your symptoms or condition. Interpretation of ultrasound results is typically done in conjunction with other clinical information and laboratory tests. Depending on the findings, further imaging, additional tests, or specific treatment plans may be recommended.