Introduction

• The procedure is best perfomed in a quiet room with reduced lighting Abdominal ultrasound video 05: spleen 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 splenomegaly.
  • Palpable or radiographic splenic mass.
  • Palpable or radiographic mid-abdominal mass.
  • Metastatic disease.
  • Infiltrative or inflammatory disease.

Advantages

• Non-invasive, in many cases sedation not required and rare to require anesthesia.
• Straightforward.
• Non-painful.
• Available in many practices.
• Allows guided biopsies.
• Short time required for assessment: 10-25 minutes, 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.
• If chemical restraint is necessary, several drugs cause splenomegaly, including barbituates, phenothiazines, halothane.

Problems

• Inadequate probe-skin contact:
  • Inadequate clipping of coat.
  • Inadequate use of ultrasound gel.
• Inadequate restraint of an active dog.
• Equipment failure.

Alternatives

• Radiography Radiography: abdomen : provides information about size, shape, position, and radiodensity of organ and not internal architecture.
• Cytopathology Fine-needle aspirate : fine needle aspirates can be obtained from enlarged spleens for cytological examination. The diagnostic value of this technique is improved by combining it with ultrasonography to guide the needle to the site of interest (particularly with focal lesions).
• Histopathology: biopsy taken at laparotomy. Cutting needle biopsy is occasionally used with post-biopsy monitoring for hemorrhage.
• MRI/CT: provide detailed information about architecture of organ but use limited by reduced availability of equipment except through referral centers.

Criteria

• Is the ultrasound examination appropriate?
• Can splenic 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

Procedure

Normal Anatomy

Pathological changes

Further Reading

Publications

Refereed papers

• Recent references from PubMed and VetMedResource.
• Saunders H M, Neath P J & Brockman D J (1998) B-Mode and doppler ultrasound imaging of the spleen with canine splenic torsion - a retrospective evaluation. Vet Radiol and Ultras 39 (4), 349-353 PubMed.
• Hardie E M, Vaden S L, Spaulding K et al (1995) Splenic infarction in 16 dogs - A retrospective study. J Vet Intern Med 9 (3), 141-148 PubMed.
• Lamb C R, Hartzb L E, Tidwell A S et al (1991) Ultrasonographic findings in hepatic and splenic lymphosarcoma in dogs and cats. Vet Radiol 32 (3), 117-120 VetMedResource.
• Wrigley R H, Park R D, Konde L J et al (1988) Ultrasonographic features of splenic hemangiosarcoma in dogs - 18 cases (1980-1986). JAVMA 192 (8), 1113-1117 PubMed.
• Wrigley R H, Konde L J, Park R D et al (1988) Ultrasonographic features of splenic lymphosarcoma in dogs - 12 cases (1980-1986). JAVMA 193 (12), 1565-1568 PubMed.

Other sources of information

• Nyland T G, Mattoon J S & Wisner E R (1995) Ultrasonography of the spleen. In: Veterinary Diagnostic Ultrasound. Eds: Nyland T G & Mattoon J S. W B Saunders Company, Philadelphia. pp 74 - 84.