41 - Kidneys and Ureters Flashcards
Which projection provides more longitudinal separation of kidneys?
Right lateral
At what level are the kidneys identified in dogs and cats?
Dogs: Right T13; Left L1-3 Cats: both L1-L4.
Detail the radiographic measurements of renal length in dogs and cats
ALL relative to L2 (VD best)
Dogs - 2.5-3.5
Cats - 2.4-3.0 x L2
Older cats: 1.9-2.6
Intact cats: 2.1-3.2 vs neutered: 1.9-2.6
List 3 contraindications for IVU
Hypotension / dehydration
Anuric renal failure
Known sensitivity to contrast agent
Recommended dose of iodine for IVU?
600-700mg/kg
At what time is opacification of the renal arteries seen following IVU?
5-7 secs
Describe the normal timings of the nephrogram phase in IVU
Starts at 10secs -> 2mins, then pyelogram starts
- Initially cortex may be more opaque
Renal opacification progressively decreases -> only 25% dogs have persistent nephrogram at 2 hrs
Describe the normal features of the pyelogram phase
Occurs after approx 2 mins
Neither renal pelvis or diverticula should be blunted or rounded.
Normal renal pelvis <2mm
Name 5 considerations that effect the duration and intensity of opacification in IVU
Hydration status
Contrast dose
Renal perfusion
GFR
Tubular resorption of water
-> IMPRECISE measure of renal function
How does the renal cortex compare to the liver and spleen?
Hypo to iso in most.
Can be hyper in absence of renal disease
Hyper may be associated with fat deposition in cats!
Describe US measurements of renal size
Cats: 3-4.3cm
Dogs: 3-10cm. Or 10mm per 10lb!
5.5-9.1 x Ao diameter at level of kidney
Name the arteries of the kidney
What is the normal resistive index and pulsatility index of the kidney in the dog and cat?
RI:
Dog: <0.72
Cat: <0.7
PI:
Dog: 1.52
Cat: 1.29
At what time are ureters best visualised in contrast CT? And what positional considerations are there?
3 mins
Sternal with pelvis elevated -> pooling in apex away from UVJ
Define CT measurements of renal size
vs L2: 2.7 (2.5-2.9)
Length:Ao: 7.4 (7.0-7.7)
List Ddx for changes in renal size, shape
Clue:
Mild enlargement + smooth (8);
Marked enlargement + smooth (7)
Enlargement + irregular (9)
Small + smooth / irreg (4)
List US features of acute nephropathy (3)
Renomegaly
Cortical hyperechogenicity
Perirenal / subcapsular effusion
A change in which parameter has been associated with active tubulointerstitial or vascular disaese?
Elevated resistive index
What features have been described with ethylene glycol toxicity? Why?
Markedly increased cortical and medullary echogenicity. Hypoechoic halo at CM junction; hypoechoic central medullary region.
Attributed to calcium oxalate deposition
What US features have been described in renal lymphoma? NPV and PPV have been defined for one feature….
Bilateral, irregular renomegaly
Masses, focal/multifocal nodules also described
SUBCAPSULAR RIM
NPV: 66%
PPV: 81%
The medullary rim sign is observed with haemorrhage, necrosis and mineralisation. Which disease processed has it been associated with (4)?
ALSO SEEN WITH NORMAL ANIMALS!
Acute tubular necrosis
FIP (pyogranulomatous vasculitis)
Hypercalcaemic nephropathy
Lepto
What US feature is described with giant kidney worms (Dioctophyme renale)?
Ring or band like structures in region of CM junction
What is the predominant histopathological finding in CKD?
Chronic tubulointerstitial inflammation and fibrosis
PKD is associated with which animals??
Long haired cats (autosomal dominant) -\> may be associated with hepatic and pancreatic cysts CAIRN TERRIERS (autosomal recessive)
