1. Kidney and Bladder US
Mike Ackerley

2. Kidney Advantage over other modalities? What do you see normally?
What can we diagnose?

3. Advantages
Ease with which the extent of the disease can be determined within the kidney for focal disease
Ease of assessment of renal pelvic or ureteral dilation when fluid distended
The location and relevance of renal mineralization can also be assessed
When radiographically ID focal renal pelvic or ureteral mineral opacities and the question of whether hydronephrosis is present
Biopsy or fine-needle aspiration can be expedited by ultrasonographic guidance, improving the margin of safety as well.

4. Normals Length in saggital plane Cortex Medullary Papillae
Dog: variable with size of dog
Cat: 2.8 – 4.2 cm
Cortex
In dogs more bright than the liver, but less bright than spleen
In cats variable, may be equal brightness to that of liver and approach that of the spleen
Medullary Papillae
The renal medulla in dogs and cats is less echogenic than the cortex.
Arcuate vessels
Pelvic recess
Renal vessels
Renal pelvis
If high resolution (7.5 – 10 MHz) transducer is used
The echotexture (Brightness) consideration is important for assessing diseases that do not alter the kidney architecture (tubular necrosis, FIP)

5. Capsule
Pelvis
Cortex
Medulla

6. Pathology
Distension
Diuresis: bilaterally symmetrical and usually mild
Hydronephrosis: pelvic dilation may become very gross, with only a think rim of surrounding parenchymal tissue (idiopathic, or secondary to ureteric obstruction)
Renal calculus: strongly reflective surface with distal acoustic shadowing also present.
Chronic pyelonephritis: the pelvis may dilate while the diverticula remain small
Renal neoplasia: secondary dilation of the renal pelvis and proximal ureter, or mechanical obstruction of the pelvis
Ectopic ureter: due to stenosis of the ureter ending and/or ascending infection
Renal pelvic blood clot: following renal biopsy, coagulopathy, bleeding neoplasm, idiopathic renal hemorrhage, or trauma

7. Hydronephrosis
Picture

8. Hydronephrosis

9. Pathology Focal parenchymal abnormalities
Well circumscribed, anechoic parenchymal lesion
Hypoechoic parenchymal lesion
Hyperechoic parechymal lesion
Heterogeneous/complex parenchymal lesion
Medullary rim sign
Acoustic shadowing

10. Pathology Well circumscribed, anechoic parenchymal lesion
Thin smooth wall: single or multiple cysts
Thick/irregular wall:
Cyst
Hematoma
Abscess
neoplasia

11. Pathology Hypoechoic parenchymal lesion Hyperechoic parenchymal lesion
Neoplasia
Lymphosarcoma
Hyperechoic parenchymal lesion
1º: chondrosarcoma, hemangioma
Metastatic: hemangiosarcoma, thyroid adenocarcinoma

12. Pathology Heterogeneous/ Complex parenchymal lesion Neoplasia Abscess
Hematoma
Granuloma
Acute infarct
Polycystic disease

13. Polycystic Kidneys

14. Renal Infarct

15. Pathology Medullary rim sign Normal in cats Nephrocalcinosis
Ethylene glycol toxicity
Chronic interstitial nephritis
Cats - FIP

16. Pathology
Acoustic Shadowing
Deep to pelvic fat
Renal calculus

17. Nephrolith

18. Pathology Diffuse parenchymal abnormalities
Increased cortical echogenicity
Decreased corticomedullary definition

19. Pathology Increased cortical echogenicity Normal cats
Inflammatory disease
Glomerulonephritis
Interstitial nephritis
FIP
Acute tubular necrosis/nephrosis (toxins)
Renal dysplasia
Nephrocalcinosis
Neoplasia
Diffuse lymphosarcoma

20. Pathology Decreased corticomedullary definition End-stage kidneys
Multiple small cysts

21. What can we diagnose? Infarcts Cysts/Abscess/Hematoma Renal calculus
Big neoplasia
Pelvic Dilation

22. Bladder Advantage over other modalities? What do you see normally?
What can we diagnose?

23. Advantages Able to evaluate bladder wall thickness
Able to visualize non-radiopaque stones/cyrstals (C U)
Cystocentesis

24. Normals
Best when bladder moderately full Ovoid in shape, with slight elongation caudally at trigone
Don’t normally see ureters
Three layers (∆ with size)
Mucosa: Hyperechoic
Muscular: Hypo-
Serosal: Hyper-
Normal wall thickness (cat): 1.7 mm ± 0.56
Normal wall thickness (dog): 1.6 mm

25. Pathology
Calculi
acoustic shadows are observed deep to calculi that exceed the diameter of the beam.
echogenicity and acoustic shadow generation are independent of chemical composition (doesn’t matter struvite VS cystine)
Ballottement doesn’t move calculi, but let animal stand and calculi will fall.
Helps differentiate from mineralized bladder wall and colonic shadowing

26. Cystic Calculi

27. Pathology Gas bubbles Blood clots Crystalline sediment
Will float to the top, to differentiate from calculi
Blood clots
non-shadowing
Crystalline sediment
Vigorous ballottement
Swirling pattern when standing

28. Blood Clot

29. Pathology
Mural changes
Cystitis
Neoplasia

30. Pathology
Cystitis
Chronic cystitis results in diffuse thickening of the bladder wall
bladder wall becomes abnormally hypoechoic, and the normal layering becomes less parallel
normal sonographic appearance of the bladder does not rule out the presence of mild or acute cystitis or idiopathic lower urinary tract disease in cats

31. Chronic Cystitis

32. Pathology
Neoplasia
TCC: irregularly shaped, broad-based, hypoechoic masses protruding into the bladder lumen
echo pattern depends on if if fibrosis, mineralization, and necrosis have developed
An abrupt transition often observed between neoplastic mass & adjacent bladder wall

33. Neoplasia

34. Pathology
Sonographic appearance of polypoid cystitis, adherent blood clots, and mural hematomas is similar to that of neoplasia
Observation of ureter dilation adjacent to the bladder wall mass & focal medial iliac lymphadenopathy tends to support the diagnosis of neoplasia
Need aspirate, but must weigh that benefit against the possibility of seeding the needle tract with tumor cells
Traumatic catheterization is useful to retrieve cells from the mass

35. What can we diagnose?
Crystalline sediment
Calculi
Blood clots?
Gas