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Introduction ⬇

The kidney (renal) ultrasound is a noninvasive imaging test performed to visualize kidney parenchyma and associated structures, including renal blood vessels. This procedure is often performed after an intravenous pyelogram (IVP) to define and characterize mass lesions or the cause of a nonvisualized kidney. Because no contrast medium is administered, a kidney ultrasound is valuable for visualizing the kidneys of patients with iodine hypersensitivities. This procedure is also helpful in monitoring the status of a transplanted kidney, guiding stent and biopsy needle placement, and evaluating the progression of chronic conditions. Kidney ultrasound is the preferred method for evaluating possible hydronephrosis in patients with spinal cord injury.

Procedure ⬆ ⬇

  1. Have the patient lie still on an examining table. Scans are often performed with the patient in the decubitus position.

  2. Apply the coupling agent (ultrasound gel) to the patient’s skin.

  3. Ask the patient to inhale as deeply as possible for visualization of the upper parts of the kidney.

  4. Tell the patient that the total study time varies from 15 to 30 minutes.

  5. See Chapter 1 guidelines for intratest care.

Procedural Alert

  1. Scans cannot be done over open wounds or through dressings.

  2. This examination must be performed before x-ray studies involving barium. If such scheduling is not possible, at least 24 hours must elapse between the barium procedure and the kidney ultrasound.

  3. Biopsies or drainage procedures are often done with ultrasound as a guide. If an invasive procedure is to be done, a signed, witnessed consent form must be obtained.

Clinical Implications ⬆ ⬇

  1. Abnormal pattern readings reveal:

    1. Cysts

    2. Solid masses

    3. Hydronephrosis

    4. Obstruction of ureters

    5. Calculi

  2. Results provide information on the size, location, and internal structure of a nonfunctioning kidney.

  3. Results differentiate between bilateral hydronephrosis, polycystic kidneys, and the small, end-stage kidneys of glomerulonephritis or pyelonephritis.

  4. Results may be used to monitor kidney development in children with congenital hydronephrosis. This approach is considered safer than repeated IVP studies.

  5. Perineal fluid collections such as those associated with complications of transplantation may be detected. These collections include abscesses, hematomas, urinomas, and lymphoceles.

  6. Solid lesions may be differentiated from cystic lesions.

  7. The spread of cancerous conditions from the kidney into the renal vein or inferior vena cava can be detected.

  8. If ultrasound is combined with Doppler evaluations, the patency and flow characteristics of the renal vessels may be scrutinized.

Interventions ⬆ ⬇

Pretest Patient Care

  1. Explain the purpose and procedure of the test.

  2. Ensure that a signed consent is in the patient’s medical record if an invasive procedure is to be performed.

  3. Assure the patient that there is no pain involved and that the only discomfort is that caused by lying still for a long period.

  4. Explain that a liberal coating of coupling agent must be applied to the skin so that there is no air between the skin and the transducer and to allow for easy movement of the transducer over the skin. A sensation of warmth or wetness may be felt. The couplant (ultrasound gel) does not stain or discolor clothing, but the patient may prefer to don a gown.

  5. Explain that the patient will be instructed to control breathing patterns while the images are being made.

  6. Check with your ultrasound department for guidelines about fasting. It usually is not necessary but may be required in certain laboratories.

  7. Follow guidelines in Chapter 1 for safe, effective, informed pretest care.

Posttest Patient Care

  1. Review test results; report and record findings. Modify the nursing care plan as needed.

  2. Counsel the patient appropriately about further testing (computed tomography scans, biopsies) and treatment of chronic conditions.

  3. Follow guidelines in Chapter 1 for safe, effective, informed posttest care.

Interfering Factors ⬆ ⬇

  1. Retained barium from radiology studies causes poor results.

  2. Obesity adversely affects tissue visualization.

Reference Values ⬆

Normal