Canis ISSN: 2398-2942

Ultrasonography: liver

Contributor(s): Andrew Holloway, Paul Mahoney, Barbara J Watrous

Introduction

  • The procedure is best perfomed in a quiet room with reduced lighting Abdominal ultrasound video 04: liver examination.
  • The patient should be still for the examination, occasionally sedation is required.
  • A nurse is required to assist in restraint of the patient.
  • Optimal probe to skin contact is required.
  • The patient identification, date, and name of practice should be entered into the ultrasound machine before commencing the procedure.
  • Images of the examination should be kept for future reference, either as thermal prints, on video tape, on multiformat camera, or saved on hard disk.

Uses

  • Assessment of:
    • Palpable or radiographic hepatomegaly Liver hepatomegaly (Cushings disease) - radiograph lateral.
    • Palpable or radiographic hepatic mass Abdomen hepatomegaly (tumor) - lateral radiograph.
    • Radiographically small liver Liver microhepatica - radiograph.
    • Palpable or radiographic cranial abdominal mass.
    • Metastatic disease.
    • Ascites Abdomen ascites - ultrasound.
    • Jaundice.
    • Abnormalities in hepatic biochemical parameters Hematology: prothrombin time.
    • Fever of unknown origin.

Advantages

  • Non-invasive, in some cases sedation not required and rare to require anesthesia.
  • Straightforward.
  • Non-painful.
  • Available in many practices.
  • Allows guided biopsies Biopsy: ultrasound-guided.
  • Short time required for assessment: 10-20 min, dependent upon patient compliance, and skill of ultrasonographer.
    Experience will significantly reduce time required.

Disadvantages

  • Requires clipping of patient's coat.
  • Normal ultrasonographic appearance does not exclude disease.
  • Abnormal ultrasonographic appearance does not always represent significant disease.
  • Similar ultrasonographic appearance with different diseases.

Problems

  • Inadequate probe-skin contact:
    • Inadequate clipping of coat.
    • Inadequate use of ultrasound gel.
    • Inadequate restraint of an active dog. Significant gastric distention from aerophagia reduces visibility. Avoid sedatives that aggravate gastric activity.
    • Equipment failure.

Alternatives

  • Radiography: provides information about size, shape, radiopacity and margination of organ but not internal architecture.
  • Cytopathology: fine needle aspirates can be obtained from the liver for cytological examination. The diagnostic value of these techniques is improved by combining it with ultrasonography to guide the biopsy needle to the site of interest (particularly with focal lesions).
  • Histopathology: percutaneous trucut biopsy or surgical biopsy taken at laparotomy. The diagnostic value of the former is also enhanced by combining it with ultrasonography.
  • MRI/CT: provide detailed information about architecture of organ but use limited by reduced availability of equipment except through referral centers.
  • Angiography: portovenography can be used to assess the portal vein.

Criteria

  • Is the ultrasound examination appropriate?
  • Can hepatic disease be confirmed without it?
  • Can intra-abdominal metastatic disease be confirmed without it?
  • Will the examination tell you what you need to know?
  • Will the management of the patient be affected by the findings?
  • Do you possess appropriate skills required?
    • Knowledge of normal anatomy, including location, vascular supply and drainage, and lymphatic drainage.
    • Knowledge of the normal ultrasonographic appearance.
    • Knowledge of the parenchymal variations seen with non-neoplastic disease.

Equipment

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Procedure

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Normal Anatomy

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Pathological changes

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Contrast enhanced ultrasonography

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Further Reading

Publications

Refereed papers

  • Recent references from VetMed Resource and PubMed.
  • Nyman H T, Kristensen A T, Kjelgaard-Hansen M & McEvoy F J (2005) Contrast-enhanced ultrasonography in normal canine liver. Evaluation of imaging and safety parameters. Vet Radiol Ultrasound 46(3), 243-250 PubMed.
  • O'Brien R T, Iani M, Matheson J, Delaney F, Young K (2004) Contrast harmonic ultrasound of spontaneous liver nodules in 32 dogs. Vet Radiol Ultrasound 45(6), 547-553 PubMed.
  • Szatmari V, Harkanyi Z, Voros K (2003) A review of nonconventional ultrasound techniques and contrast-enhanced ultrasonography of noncardiac canine disorders. Vet Radiol Ultrasound 44(4), 380-391 PubMed.
  • Salwei R M, O'Brien R T, Matheson J S (2003) Use of contrast harmonic ultrasound for the diagnosis of congenital portosystemic shunts in three dogs. Vet Radiol Ultrasound 44(3), 301-305 PubMed.
  • Ziegler L E, O'Brien R T, Waller K R, Zagzebski J A (2003) Quantitative contrast harmonic ultrasound imaging of normal canine liver. Vet Radiol Ultrasound 44(4), 451-454 PubMed.
  • Hittmair K M, Vielgrader H D & Loupal G (2001) Ultrasonographic evaluation of gallbladder wall thickness in cats. Vet Rad Ultrasound 42(2), 149-156.
  • de Rycke L M, van Bree H J & Simoens P J (1999) Ultasound-guided tissue-core biopsy of the liver, spleen and kidney in normal dogs. Vet Radiol Ultrasound 40(3), 294-299 PubMed.
  • Bromel C, Barthez P Y, Leveille R & Scrivani P V (1998) Prevalence of gallbladder sludge in dogs as assessed by ultrasonography. Vet Radiol Ultrasound 39(3), 206-210.
  • Schwartz L A, Pennick D G & Leville-Webster C (1998) Hepatic abscesses in 13 dogs - A review of the ultrasonic findings, clinical data and therapeutic options. Vet Radiol Ultrasound 39(4), 356-365 PubMed.
  • Holt D E, Scheeling C G, Saunder H M & Orsher R J (1995) Correlation of ultrasonic findings with surgical, portographic and necropsy findings in dogs abd cats with portosystemic shunts - 63 cases. JAVMA 207(9), 1190-1193.
  • Biller D S, Kantrowitz B & Miyabayashi T (1992) Ultrasonography of diffuse liver disease - A review. J Vet Intern Med 2, 71-76.
  • Barr F (1992) Ultrasonographic assessment of liver size in the dog. JSAP 33, 359-364.
  • Lamb C R, Hartzband L E, Tidwell A S & Pearson S H (1991) Ultrasonographic findings in hepatic and splenic lymphosarcoma in dogs and cats. Vet Radiol 32, 117-120.

Other sources of information

  • Lamb C R (1998) Ultrasonography of portosystemic shunts in dogs and cats. Vet Clin North Am Small Anim Pract 28(4), 725-753.
  • Partington B P, Biller D S (1998) Hepatic imaging with radiology and ultrasound. Vet Clin North Am Small Anim Pract 28(4), 725-753.
  • Nyland T G, Mattoon J S & Wisner E R (1995) Ultrasonography of the liver. In: Veterinary Diagnostic Ultrasound. Eds Nyland T G & Mattoon J S. WB Saunders Company, Philadelphia. pp 52-73.


ADDED