1. Ultrasonography
The Spleen
VCA 341
Dr. LeeAnn Pack

2. Indications Splenomegaly Palpable splenic mass
Cranial abdominal organomegaly
Lethargy, collapse
Anemia, abnormal RBC’s

3. Ultrasound Technique Left side of body Head of spleen
Under border of rib cage on left
Body & tail of spleen
Along left body wall
Ventral or lateral to left kidney
Scan sagittal & transverse

4. Anatomy Size of normal spleen variable Parenchyma Echogenicity
Assessed subjectively
Enlarged spleen may cross midline or extend caudally to the bladder
Parenchyma
Homogenous, finely textured
Echogenicity
Dog: Spleen > liver > kidney
Cat: Spleen = liver > kidney

5. Normal Spleen

6. Anatomy Capsule Splenic veins Hilus Smooth, regular, VERY echogenic
Only other structure normally visualized
Poorly visualized except near hilus
“Whale tail”
Enlargement subjective
Hilus
Check for lymphadenopathy

7. Splenic Hilus

8. Pathology Diffuse splenomegaly Congestion Torsion
Inflammation/septicemia
Neoplasia
Lymphosarcoma
Mast cell tumor
Phenothiazine tranquilizers & barbiturate anaesthetics
Extramedullary hematopoesis

9. Pathology Focal or multifocal splenic lesions Hematoma Infarcts Cysts
Abscess
Nodular hyperplasia
Neoplasia
Hemangioma
Hemangiosarcoma

10. Diffuse Splenomegaly Diffuse increase in echogenicity uncommon
Neoplastic (mast cell or lymphosarcoma)
Diffuse decrease in echogenicity more common
Congestion
Extra-medullary hematopoesis
Lymphosarcoma
Inflammation/ septicemia
Torsion
Normal echogenicity can occur with lymphosarcoma & mast cell tumor
Break this slide up

11. Non Homogenous

12. Focal/Multifocal Lesions
More common than diffuse
Anechoic
Cysts
Hematoma/neoplasia
Hypoechoic
Neoplasia
Abscess
Acute infarct
Nodular hyperplasia

13. Focal/Multifocal Lesions
Hyperechoic
Neoplasia
Abscess
Chronic infarct
Nodular hyperplasia
Mixed echogenicity
Hematoma

14. Splenic Mass

15. Splenic Mass

16. Splenic Infarct

17. Torsion Definitive diagnosis by ultrasound Characteristic appearance
Severe, diffuse splenomegaly
Hypoechoic
Coarse & “lace-like”
Venous blood flow absent on Doppler
+/- hyperechoic venous thrombi
Lymphosarcoma can appear similar
Normal blood flow

18. Torsion

19. Neoplasia Lymphosarcoma Hematoma, hemangioma, hemangiosarcoma
Diffuse or focal/multifocal
Hypoechoic or hyperechoic
Can appear normal
Hematoma, hemangioma, hemangiosarcoma
Unable to differentiate
Focal
Hypoechoic, hyperechoic or mixed

20. Lymphosarcoma

21. Hemangiosarcoma

22. Neoplasia Other neoplasms
Mast cell tumor, leiomyoma, etc.
Presence of peritoneal effusion not a good indication of malignancy
Metastasis
Lungs, liver, lymph nodes (splenic, hepatic, gastric)

23. Echogenic Focal Lesions
Focal fat deposits
Especially cats
Surround hepatic veins (myelolipomas)
Fibrosis & calcification
Secondary to hematoma, chronic infarcts or granulomas (histoplasmosis)
Primary or metastatic neoplasia

24. Definitive Diagnosis
Ultrasonic appearance of most splenic diseases non-specific
Consider history, signalment, clinical signs
Fine needle aspirate useful
Biopsy generally not performed
Does this apply to neoplasms? Focal lesions? What exactly?

25. Rupture Free fluid within the abdomen Most likely a tumor
Often echoic (due to  blood cells)
May be anechoic
Most likely a tumor
Cannot rule out hematoma

26. Thrombosis

27. Splenic Thrombus

28. Myelolipoma