Felis ISSN 2398-2950

Fine needle aspirate: ultrasound-guided

Synonym(s): FNA: ultrasound-guided

Contributor(s): Andrew Holloway, Fraser J McConnell, Tobias Schwartz


  • For use in the investigation of any accessible mass or cystic lesion and:


  • Jaundice.
  • Unexplained raised liver enzymes.
  • Abnormal appearance of liver on ultrasonographic examination.
  • Diffuse liver disease Liver: chronic disease (inflammatory, infiltrative, neoplastic).
  • Mass lesions.
  • Aspiration of bile.


  • Diffuse diseases (acute or chronic nephritis).
  • Protein losing nephropathy.
  • Mass lesions.


  • Useful for solid masses.
    Avoid cavitatory lesions.

Gastrointestinal tract  

  • Mass lesions.


  • Mass lesions of chest wall, mediastinum or lung.
  • Aspiration of thoracic effusions.

Lymph nodes

  • Lymphadenopathy.


  • Diffuse or multifocal non-cystic prostatic disease Prostate gland: disease.
  • Solid prostatic masses.
  • Aspiration of cystic structures for diagnostic or therapeutic purposes.


  • Low cost.
  • Minimally-invasive.
  • Rapid.
  • Straightforward in hands of experienced operator.
  • Short time requirement.
  • Often performed without general anesthesia.
  • Minimal risk of complication.


  • Requires patient's coat to be clipped.
  • Difficult to obtain samples in obese patients, from deeply located structures, highly vascularized lesions and in the presence of a large amount of fluid.
  • Samples may be non-diagnostic or non-representative of disease process.
  • Requires significant operator skill.
  • General anesthesia General anesthesia: overview may be required.

Potential problems

  • Seeding of tumor with bladder carcinomas Bladder: neoplasia.
  • Hemorrhage:
  • Penetration of other viscera.
  • Inadequate patient restraint:
    • Movement could result in laceration of vessels or organ.
  • Operator inexperience.
  • Excess intestinal gas or large gall bladder may limit visibility of target tissue.
  • Inadequate equipment (needle diameter too small or too short).
  • Failure to visualize needle due to improper technique or patient factors (obese, excessive respiratory movement).
  • Target may be too small to safely obtain sample (particularly in small dogs and cats).
  • Non-diagnostic sample:
    • Hemodilution - especially spleen and liver.
    • Fibrotic or cirrhotic livers may produce poor samples due to poor exfoliation.
    • Sample size may be too small.
    • Sample not from affected area (multifocal disease).



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Patient preparation

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Further Reading


Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Nyland T G, Wallack S T, Wisner E R (2002) Needle-tract implantation following us-guided fine-needle aspiration biopsy of transitional cell carcinoma of the bladder, urethra, and prostate. Vet Radiol Ultrasound 43 (1), 50-53 PubMed.
  • Bennett P F, Hahn K A, Toal R L et al (2001) Ultrasonographic and cytopathological diagnosis of exocrine pancreatic carcinoma in the dog and cat. J Am Anim Hosp Assoc 37 (5), 466-473 PubMed.
  • Szatmári V, Osi Z, Manczur F (2001) Ultrasound-guided percutaneous drainage for treatment of pyonephrosis in two dogs. JAVMA 218 (11), 1796-1799, 1778-1779 PubMed.
  • Samii V F, Nyland T G, Werner L L et al (1999) Ultrasound-guided fine-needle aspiration biopsy of bone lesions: a preliminary report. Vet Radiol Ultrasound 40 (1), 82-86 PubMed.
  • Wood E F, O'Brien R T, Young K M (1998) Ultrasound-guided fine-needle aspiration of focal parenchymal lesions of the lung in dogs and cats. J Vet Intern Med 12 (5), 338-342 PubMed.
  • Barr F (1995) Percutaneous biopsy of abdominal organs under ultrasound guidance. J Small Anim Pract 36 (3), 105-113 PubMed.
  • Léveillé R, Partington B P, Biller D S et al (1993) Complications after ultrasound-guided biopsy of abdominal structures in dogs and cats: 246 cases (1984-1991). JAVMA 203 (3), 413-415 PubMed.
  • Yamamoto K, Ishiyama N, Yamaga Y et al (1991) Ultrasound-guided techniques for biopsy of the kidney of the medium-sized dog. J Vet Med Sci 53 (2), 345-346 PubMed.
  • McNamara M P Jr. (1989) Percutaneous procedures guided by color-flow Doppler sonography. AJR Am J Roentgenol 152 (5), 1123-1125 PubMed.
  • Smith S (1989) Ultrasound-guided biopsy. Semin Vet Med Surg (Small Anim) (1), 95-104 PubMed.
  • Smith S (1985) Ultrasound-guided biopsy. Vet Clin North Am Small Anim Pract 15 (6), 1249-1262 PubMed.