Ultrasound, Liver and Biliary System

Ultrasound, Liver and Biliary System

Synonym/acronym: Gallbladder ultrasound, liver ultrasound, hepatobiliary sonography.

Common use

To visualize and assess liver and gallbladder structure and function, assist in obtaining a biopsy, and diagnose disorders such as gallstones, cancer, tumors, cysts, and bleeding. Also used to evaluate the effectiveness of therapeutic interventions.

Area of application

Liver, gallbladder, bile ducts.

Contrast

Done without contrast.

Description

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, tube placement, and fluid aspiration. The contraindications and complications for biopsy and fluid aspiration are discussed in detail in the individual monographs.

Hepatobiliary US is used to evaluate the structure, size, and position of the liver and gallbladder in the right upper quadrant (RUQ) of the abdomen. The gallbladder and biliary system collect, store, concentrate, and transport bile to the intestines to aid in digestion. This procedure allows visualization of the gallbladder and bile ducts when the patient may have impaired liver function, and it is especially helpful when done on patients in whom gallstones cannot be visualized with oral or IV radiological studies. Liver US can be done in combination with a nuclear scan to obtain information about liver function and density differences in the liver.

This procedure is contraindicated for

    N/A

Indications

  • Detect cysts, polyps, hematoma, abscesses, hemangioma, adenoma, metastatic disease, hepatitis, or solid tumor of the liver or gallbladder, as evidenced by echoes specific to tissue density and sharply or poorly defined masses
  • Detect gallstones or inflammation when oral cholecystography is inconclusive
  • Detect hepatic lesions, as evidenced by density differences and echo-pattern changes
  • Determine the cause of unexplained hepatomegaly and abnormal liver function tests
  • Determine cause of unexplained RUQ pain
  • Determine patency and diameter of the hepatic duct for dilation or obstruction
  • Differentiate between obstructive and nonobstructive jaundice by determining the cause
  • Evaluate response to therapy for tumor, as evidenced by a decrease in size of the organ
  • Guide biopsy or tube placement
  • Guide catheter placement into the gallbladder for stone dissolution and gallbladder fragmentation

Potential diagnosis

Normal findings

  • Normal size, position, and shape of the liver and gallbladder as well as patency of the cystic and common bile ducts

Abnormal findings related to

  • Biliary or hepatic duct obstruction/dilation
  • Cirrhosis
  • Gallbladder inflammation, stones, carcinoma, polyps
  • Hematoma or trauma
  • Hepatic tumors, metastasis, cysts, hemangioma, hepatitis
  • Hepatocellular disease, adenoma
  • Hepatomegaly
  • Intrahepatic abscess
  • Subphrenic abscesses

Critical findings

    N/A

Interfering factors

  • Factors that may impair clear imaging

    • Attenuation of the sound waves by bony structures, which can impair clear imaging of the right lobe of the liver
    • 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
    • Gas or feces in the gastrointestinal tract resulting from inadequate cleansing or failure to restrict food intake before the study
    • Retained barium from a previous radiological procedure

  • Other considerations

    • Failure to follow dietary restrictions may cause the procedure to be canceled or repeated.

Nursing Implications and Procedure

Pretest

  • 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 liver and biliary 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 hepatobiliary 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.
  • 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 and explain 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) who specializes in this procedure, 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.
  • Instruct the patient to fast and restrict fluids for 8 hr prior to the procedure. Protocols may vary among facilities.

Intratest

  • Potential complications: N/A
  • Observe standard precautions, and follow the general guidelines in Patient Preparation and Specimen Collection. Positively identify the patient.
  • Ensure that food and fluids have been restricted for at least 8 hr prior to the procedure.
  • 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 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.

Post-Test

  • 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.
  • Instruct the patient to resume usual diet and fluids, as directed by the HCP.
  • 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 ALP, ALT, AST, bilirubin, biopsy liver, cholangiography, colonoscopy, CT abdomen, endoscopy, ERCP, GGT, haptoglobin, hepatitis (A, B, C antigens and/or antibodies), hepatobiliary scan, laparoscopy abdominal, MRI abdomen, radiofrequency ablation liver, and US abdomen.
  • Refer to the Hepatobiliary System table at the end of the book for related tests by body system.