A renal ultrasound is a non-invasive diagnostic test that uses high-frequency sound waves to produce images of the kidneys and the bladder. Kidneys act as a filtration system, cleaning waste from the blood and expelling it from the body via urine. These vital organs also help regulate blood pressure and balance salt levels in the blood.
An ultrasound is a simple, diagnostic tool that doctors use to take a look inside your body. Ultrasounds use high-frequency sound waves to show doctors your internal organs and structures in real-time, helping them detect conditions like blood clots, gallstones, cancer, and more. Ultrasounds are a form of diagnostic imaging, just like x-rays or CT scans.
From physical therapists to obstetricians/gynecologists (OB/GYN), all kinds of healthcare providers use ultrasound imaging to diagnose and treat their patients. You may sometimes hear doctors call ultrasounds “sonography” or “sonograms.” These terms are interchangeable with “ultrasound”.
Renal ultrasounds allow doctors to examine the inside of your body without surgery.
An ultrasound of the kidneys can help doctors detect medical conditions such as:
- Cysts
- Renal abscesses (pockets of pus in the kidney)
- Tumors
- Infections
- Inflammation
- Kidney stones
- Blockage
These conditions can cause severe symptoms - even death - if not treated promptly. If you are exhibiting signs of kidney troubles, your doctor may order a renal ultrasound as a diagnostic test for your condition.
In other instances, a renal ultrasound may be used as a method of tracking recovery after a kidney transplant.
While symptoms may vary depending on the condition, there are some common signs that something may be wrong with your kidney function. Symptoms of kidney conditions include:
It is important to note that these symptoms do not necessarily mean that you are experiencing kidney problems. Many of these symptoms are experienced with other conditions; however, if these symptoms are coupled with difficulty or pain during urination, an infection of the kidneys is likely. If you experience the symptoms above, talk to your health care provider about whether or not you may need a diagnostic imaging exam.
Unlike other forms of diagnostic imaging - most of which require you to fast for several hours - renal ultrasounds usually require that you drink 24-30 ounces of water an hour before the exam. After you drink this water, it is imperative that you do not use the restroom. Drinking water fills the bladder, making images of the area more clear during the ultrasound scan.
No other preparation is required. You will be asked to remove all metallic items from your person such as jewelry, piercings, eyeglasses, and dentures. Because of this, it is usually recommended that you leave most of these items (specifically jewelry and piercings) at home on the day of your appointment.
After drinking 24-30 oz of water, you will be asked to change out of your street clothes and into a hospital gown.
In the exam room, you will be asked to lie down on your stomach on a padded table. Your doctor will use a hand-held device known as a transducer, which directs high-frequency sound waves into the tissue being studied. After the area is gelled (gel helps conduct the ultrasound waves), the transducer is placed against the skin of your lower back for imaging.
As the sound waves echo off the kidney tissue, the transducer sends data to a computer that records the feedback and creates images. You may be asked to hold your breath for several seconds as images are being taken. Additionally, if the bladder is being examined as well, you may be asked to empty your bladder after images of the full bladder are taken.
This procedure usually takes about 30 minutes. Unless further testing is needed, most individuals are free to resume daily activities after their ultrasound.
After your appointment, a radiologist will review the images produced by the exam. They will then present their findings to your health care provider, who will pass on the results to you. This may take 1-3 business days, depending on the clinic.
Yes. Ultrasounds are non-invasive exams that provide real-time imaging of blood flow and organs in the body. This type of imaging is totally safe and extremely accurate.
Ultrasounds are generally less expensive than other forms of imaging. They do not require injections, nor is sedation needed for the procedure. These are quick and painless exams that usually take under an hour. After your appointment, you will likely be cleared to leave and go about your daily activities.
If you have any questions about different types of imaging, talk to your health care provider about the method that is right for you.