Renal ultrasound

Also found in: Acronyms.

Renal ultrasound

A painless and non-invasive procedure in which sound waves are bounced off the kidneys. These sound waves produce a pattern of echoes that are then used by the computer to create pictures of areas inside the kidney (sonograms).
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.

Ultrasound, Kidney

Synonym/acronym: Renal ultrasound, renal sonography.

Common use

To visualize and assess the kidneys, to perform biopsies, and assist in diagnosing disorders such as tumor, cancer, stones, and congenital anomalies. This procedure can also be used to evaluate therapeutic interventions such as transplants.

Area of application



Done without contrast.


Ultrasound (US) procedures are diagnostic, noninvasive, and relatively inexpensive. They take a short time to complete, do not use radiation, and cause no harm to the patient. High-frequency sound waves of various intensities are delivered by a transducer, a flashlight-shaped device, pressed against the skin. The waves are bounced back off internal anatomical structures and fluids, converted to electrical energy, amplified by the transducer, and displayed as images on a monitor. US is often used as a diagnostic and therapeutic tool for guiding minimally invasive procedures such as needle biopsies and fluid aspiration. The contraindications and complications for biopsy and fluid aspiration are discussed in detail in the individual monographs.

Renal US is used to evaluate the structure, size, and position of the kidneys and to identify renal system disorders. It is valuable for determining the internal components of renal masses (solid versus cystic) and for evaluating other renal diseases, renal parenchyma, perirenal tissues, and obstruction. Renal US can be performed on the same day as a radionuclide scan or other radiological procedure and is especially valuable in patients who are in renal failure, have hypersensitivity to contrast medium, have a kidney that did not visualize on IV pyelography (IVP), or are pregnant. It does not rely on renal function or the injection of contrast medium to obtain a diagnosis. The procedure is indicated for evaluation after a kidney transplant and is used as a guide for biopsy and other interventional procedures, abscess drainage, and nephrostomy tube placement. Renal US may be the diagnostic examination of choice because no radiation is used and, in most cases, the accuracy is sufficient to make the diagnosis without further imaging procedures.

This procedure is contraindicated for



  • Aid in the diagnosis of the effect of chronic glomerulonephritis and end-stage chronic renal failure on the kidneys (e.g., decrease in size)
  • Detect an accumulation of fluid in the kidney caused by backflow of urine, hemorrhage, or perirenal fluid
  • Detect masses and differentiate between cysts or solid tumors, as evidenced by specific waveform patterns or absence of sound waves
  • Determine the presence and location of renal or ureteral calculi and obstruction
  • Determine the size, shape, and position of a nonfunctioning kidney to identify the cause
  • Evaluate or plan therapy for renal tumors
  • Evaluate renal transplantation for changes in kidney size
  • Locate the site of and guide percutaneous renal biopsy, aspiration needle insertion, or nephrostomy tube insertion
  • Monitor kidney development in children when renal disease has been diagnosed
  • Provide the location and size of renal masses in patients who are unable to undergo IVP because of poor renal function or an allergy to iodinated contrast medium

Potential diagnosis

Normal findings

  • Absence of calculi, cysts, hydronephrosis, obstruction, or tumor
  • Normal size, position, and shape of the kidneys and associated structures

Abnormal findings related to

  • Acute glomerulonephritis
  • Acute pyelonephritis
  • Congenital anomalies, such as absent, horseshoe, ectopic, or duplicated kidney
  • Hydronephrosis
  • Obstruction of ureters
  • Perirenal abscess or hematoma
  • Polycystic kidney
  • Rejection of renal transplant
  • Renal calculi
  • Renal cysts, hypertrophy, or tumors
  • Ureteral obstruction

Critical findings


Interfering factors

  • Factors that may impair clear imaging

    • Attenuation of the sound waves by the ribs, which can impair clear imaging of the kidney
    • Incorrect placement of the transducer over the desired test site; quality of the US study is very dependent upon the skill of the ultrasonographer
    • Metallic objects (e.g., jewelry, body rings) within the examination field, which may inhibit organ visualization and cause unclear images
    • Inability of the patient to cooperate or remain still during the procedure because of age, significant pain, or mental status

Nursing Implications and Procedure


  • Positively identify the patient using at least two unique identifiers before providing care, treatment, or services.
  • Patient Teaching: Inform the patient this procedure can assist in assessing kidney function.
  • Obtain a history of the patient’s complaints or clinical symptoms, including a list of known allergens, especially allergies or sensitivities to latex.
  • Obtain a history of the patient’s genitourinary system, symptoms, and results of previously performed laboratory tests and diagnostic and surgical procedures.
  • Note any recent procedures that can interfere with test results (i.e., barium procedures, surgery, or biopsy). There should be 24 hr between administration of barium and this test.
  • Endoscopic retrograde cholangiopancreatography, colonoscopy, and computed tomography of the abdomen, if ordered, should be scheduled after this procedure.
  • Record the date of the last menstrual period and determine the possibility of pregnancy in perimenopausal women.
  • Obtain a list of the patient’s current medications, including herbs, nutritional supplements, and nutraceuticals (see Effects of Natural Products on Laboratory Values online at DavisPlus).
  • Review the procedure with the patient. Address concerns about pain related to the procedure. Explain to the patient that some pain may be experienced during the test, and there may be moments of discomfort. Inform the patient that the procedure is performed in a US department, usually by a health-care provider (HCP), with support staff, and takes approximately 30 to 60 min.
  • Sensitivity to social and cultural issues, as well as concern for modesty, is important in providing psychological support before, during, and after the procedure.
  • Instruct the patient to remove jewelry and other metallic objects from the area to be examined.
  • Note that there are no food, fluid, or medication restrictions unless by medical direction.


  • Potential complications: N/A
  • Observe standard precautions, and follow the general guidelines in Patient Preparation and Specimen Collection. Positively identify the patient.
  • Ensure that the patient has removed all external metallic objects from the area to be examined prior to the procedure.
  • Instruct the patient to void and change into the gown, robe, and foot coverings provided.
  • Avoid the use of equipment containing latex if the patient has a history of allergic reaction to latex.
  • Instruct the patient to cooperate fully and to follow directions. Instruct the patient to remain still throughout the procedure because movement produces unreliable results.
  • Place the patient in the supine position on an examination table. The right- or left-side-up positions may be used to allow gravity to reposition the liver, gas, and fluid to facilitate better organ visualization.
  • Expose the abdominal and kidney area and drape the patient.
  • Conductive gel is applied to the skin, and a transducer is moved over the skin to obtain images of the area of interest.
  • Ask the patient to breathe normally during the examination. If necessary for better organ visualization, ask the patient to inhale deeply and hold his or her breath.


  • Inform the patient that a report of the results will be made available to the requesting HCP, who will discuss the results with the patient.
  • When the study is completed, remove the gel from the skin.
  • Recognize anxiety related to test results. Discuss the implications of abnormal test results on the patient’s lifestyle. Provide teaching and information regarding the clinical implications of the test results, as appropriate.
  • Reinforce information given by the patient’s HCP regarding further testing, treatment, or referral to another HCP. Answer any questions or address any concerns voiced by the patient or family.
  • Depending on the results of this procedure, additional testing may be performed to evaluate or monitor progression of the disease process and determine the need for a change in therapy. Evaluate test results in relation to the patient’s symptoms and other tests performed.

Related Monographs

  • Related tests include angiography renal, anti-glomerular basement membrane antibody, biopsy kidney, BUN, calculus kidney stone panel, CT abdomen, creatinine, creatinine clearance, cytology urine, erythropoietin, group A streptococcal screen, IVP, KUB study, MRI abdomen, renogram, retrograde ureteropyelography, UA, and US abdomen.
  • Refer to the Genitourinary System table at the end of the book for related tests by system.
Handbook of Laboratory and Diagnostic Tests, © 2013 Farlex and Partners
References in periodicals archive ?
The findings of slowly progressive renal failure, bland urinalyses, and unremarkable renal ultrasounds make the correct diagnosis elusive.
All patients underwent renal ultrasound using Logiq P5 ultrasound machine (General Electric, Boston MA, USA) with a 3.5 MHz transducer.
This is because renal ultrasound has a high negative predictive value for detecting high-grade vesicoureteral reflux (VUR) in neonates, and although it has poor sensitivity for detecting low-grade VUR, its sensitivity for detecting high-grade VUR is quite good in this population.
In Pakistan it is estimated that approximately 12% of population develops urinary stones.1 Urolithiasis is the commonest cause of acute urinary tract obstruction.2 Most acute obstructive uropathies are associated with significant pain abrupt diminution of urine flow hematuria and can lead to acute and chronic renal failure.3 Renal ultrasound and Doppler studies remain vital diagnostic tools in the evaluation of urinary tract obstruction because it is a rapid low cost non invasive and radiation free tool.34 Some patients of renal obstruction presenting with acute ureteric colic are not ideal candidates for intravenous urography (IVU) e.g.
First-line investigations often include conventional radiography, renal ultrasound, and/or IVU in combination with cystoscopy.
renal ultrasound and renograms, should be shortened.
All renal ultrasound scans were done by using a single real-time ultrasound scanner using a 3.5-MHz curvilinear probe in supine and oblique positions with deep inspiration.
The follow-up assessment included a general physical examination, a renal ultrasound to assess the status of the treated cyst, and an assessment of any complications.
Each patient with APN underwent renal ultrasound and voiding cysto-ureterography (VCUG) 4-6 weeks later as part of the initial investigation.
This study recommends that all emergency admissions should have electrolytes and urinalysis checked routinely on admission, with 24-hour access to renal ultrasound. It proposed that a risk assessment for AKI should be part of the initial clerking with referral to specialist advice being sought in a timely manner.