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What Is a Renal Ultrasound Used For?

What Is a Renal Ultrasound Used For?


It is actually a diagnostic procedure. High-frequency sound waves are transmitted through the body's tissues that are inaudible to the human ear. This creates videos or photographic images of the internal structure of the body after the echoes are recorded and transformed.

Many diseases and conditions can be diagnosed with ultrasound. Any blockages in blood vessels can also be detected by ultrasound. Soft tissue structure images for the kidneys, heart, liver, gall bladder and female reproductive organs can be created with ultrasounds. Sometimes they are used alone or with other diagnostic procedures. Ultrasounds are deemed to be completely safe.

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More about the renal system

The crucially important function of renal system is urine elimination. The three necessary parts of the renal system are:

  • Kidneys - By filtering wastes and extra water, the kidneys generate urine.
  • The ureters - From the kidneys to the bladder, they transport urine.
  • Bladder - The urine is stored in the bladder and it signals the body when it's time to eliminate waste.

The entire body benefits by keeping this system healthy. The renal system functions normally by:

  • Preventing the accumulation of wastes and extra fluid in the body
  • Regulating blood pressure it makes hormones
  • Creating red blood cells
  • Keeping the bones strong
  • Stabilizing potassium and phosphate levels

Renal ultrasound

The renal ultrasound is a noninvasive diagnostic exam. The size, location, and shape of the ureters, kidney, and bladder can be assessed by renal ultrasound. The images vividly show the internal structure of the kidney and other related organs.  In this examination, blood test is combined with urinalysis which helps to reach to an accurate diagnosis.

To detect and diagnose conditions within the kidneys, bladder and ureters, renal ultrasound is used. By identifying changes in the tension of the bladder walls or in overall size and structure of the kidneys, certain conditions such as cysts, masses, kidney stones, and infections can be detected.

The importance of renal ultrasounds

The renal system, like other systems, is resilient and durable. Still, millions of Americans are at risk of chronic kidney disease, so it is recommended to undergo regular testing such as simple blood and urine tests or advanced imaging tests in some cases.

What is a renal ultrasound used for?

Renal ultrasounds can detect and assess the following:

  • Hematuria, flank pain, abnormal renal function
  • To assess, dilates upper urinary tract
  • Renal and perirenal mass found on physical or other imaging study can be assessed
  • After renal and urethral surgery, post-operative evaluation can be done
  • The dynamics of the upper tract's effects of voiding can be assessed
  • Evaluating and monitoring urolithiasis
  • For ablation or resection of masses intra operative renal parenchymal and vascular imaging
  • In patients who are not candidate for IVP, MRI or CT, hematouria can be assessed
  • Percutaneous access to renal collecting system
  • To guide cyst aspiration, transutaneous or renal biopsies, ablation of masses
  • To evaluate postoperative renal transplant patients
  • Detecting invasion by tumor and filter localization
  • In symptomatic patients to preclude obstruction
  • Changes in the size or structure of the kidney or bladder wall
  • Stones in the urinary tract
  • Changes in the ureters

In the emergency department, a relatively common complaint is acute flank pain and abdominal pain with hematuria. In such cases, urinary obstruction is a likely diagnosis, but life-threatening disease processes are included in differential diagnosis. The diagnosis of acute urinary obstruction can be rapidly confirmed by emergency sonography and it can also help to exclude life-threatening processes.

Obstructive uropathy is the structural impediment to the flow of urine. Typically, this obstruction is painful unless it develops slowly. If it causes pain, then it is known as renal colic.

In a patient with decreased urinary output in the emergency department, renal sonography is useful. It is also useful in acute renal failure and pyelonephristis. Renal ultrasound is used to evaluate any abnormalities in retroperitoneal anatomical structures, but for the functional status of the urinary system it gives only limited clues.

Usually when there is any concern related to the kidney or bladder, doctors may recommend a renal ultrasound. 

How a renal ultrasound is done

  • Preparation

For a renal ultrasound the patient should have a full bladder. For the ultrasound to confirm that the bladder is emptying properly, the patient will be emptied halfway.

  • What is expected from a renal ultrasound?

On the patient’s abdomen, ultrasound gel is placed. The organs are scanned using an ultrasound probe. The organ is examined and for analysis, multiple images are taken by a consultant radiologist. Within 48 hours of the examination, the results of the scan will be sent to the patient. The procedure lasts for around 20 minutes.

  • Before the procedure

The physician will first explain the process before he or she begins the procedure. The physician will first explain how the procedure is done. You may need to sign a consent form. Read the form carefully. If you have any doubts, get them cleared up beforehand. Before the procedure, the person does not have to do any initial preparation. 

  • During the procedure

The renal ultrasound can either be performer in the hospital or an outpatient basis. The setting depends on the condition and recommendation by the physician. The process is as follows:

  1. Any clothing that may interfere with the scan is removed and a gown is given to you
  2. The clear gel is applied
  3. A transducer is pressed at around the area that is to be studied
  4. After the examination of bladder, you may be told to empty your bladder and after that, any other scan may be performed if needed
  5. After the procedure is complete, the gel is wiped off

By performing the procedure as quickly as possible, any discomfort experienced by lying down on the stomach can be minimized.

  • After the procedure

No specialized type of care is needed after the procedure. You can continue your normal activities and resume your normal diet unless advised by the physician. However, with regard to the situation or condition, the physician may give any additional or alternative instruction.

Risks associated with renal ultrasound

In renal ultrasound radiation is not used. By applying the ultrasound transducer on the skin generally no discomfort is experienced. However, depending on the specific medical condition there could be risks as everything cannot be ruled out. So, if you have any concerns, talk to your doctor before you start the procedure. 

Risks include:

  • Intestinal gas
  • Severe obesity
  • After a recent barium procedure, barium in the intestine

These may interfere with the renal ultrasound results.

Renal ultrasound for children

For children, a renal ultrasound is not like X-ray, where the child is exposed to radiation. If there is any problem with the urinary system of the child, it can be diagnosed with renal ultrasound.

The images can help diagnose:

  • Signs of injury or trauma
  • Any abnormalities such as tumor or cysts
  • Any swelling or blockages
  • Abnormal structure of the kidney and urinary tract
  • Kidney stones