Just wondering if this is a significant finding in dogs or has anyone seen kidneys like this? Unlike the medullary rim sign in dogs and cats, is there a term for this sonographic appearance?
3 year old, FS, cavoodle was presented for repeated HGE. Blood work was unremarkable. Both kidneys were symmetrical in appearance, presenting a hypoechoic rim around the capsule.
Just wondering if this is a significant finding in dogs or has anyone seen kidneys like this? Unlike the medullary rim sign in dogs and cats, is there a term for this sonographic appearance?
3 year old, FS, cavoodle was presented for repeated HGE. Blood work was unremarkable. Both kidneys were symmetrical in appearance, presenting a hypoechoic rim around the capsule.
In humans, it is called ‘kidney sweat’ and could be a sign of renal failure–>
Perirenal lucency (“kidney sweat”): a new sign of renal failure.
Abstract
OBJECTIVE:This study describes a new sonographic finding in renal failure: perirenal lucency, which we call the “kidney sweat” sign.
MATERIALS AND METHODS:During 1 year at our institution, 502 renal sonograms were obtained. Sonography evaluated 330 patients with renal failure. All of the examinations were retrospectively analyzed.
RESULTS: An extracapsular hypoechoic rim was present in 47 (14%) of the 330 patients with renal failure. The finding, when present, was always bilateral. The hypoechoic rim was not present in the remaining 283 patients with renal failure. Forty (85%) of the 47 patients had kidneys that were hyperechoic compared with the liver. Twenty-eight (60%) of the 47 patients had kidneys that were hyperechoic compared with the spleen. In 15 (32%) of the 47 patients, the kidneys were small. Ascites was present in 11 (23%) of the 47 patients. Of the 283 patients with renal failure whose sonograms did not show the hypoechoic rim, 76 patients had normal sonographic findings. The remaining 207 patients with renal failure who did not show the kidney sweat sign had hydronephrosis, stones, cysts, echogenic kidneys, small kidneys, or ascites.
CONCLUSION: An extracapsular hypoechoic rim is found in patients with renal failure. We call this finding “kidney sweat.” We believe, but cannot currently prove, that the kidney sweat sign represents edema. It is an additional sonographic finding in patients with renal failure.
Comments
It would look like the
It would look like the hypoecchoic area might be actually cortical parenchyma. I think it may be a wide cortical hyperehoic band rather than pericapsular or sub capsular fluid…
The hypoechoic “halo” does happen. I think more in acute renal insults like infectious or intoxication. I had one just recently which I think it’s linked to a calculus moving…
But let’s see what others have to say. They may just be kidneys of no clinical significance…
This looks like a really
This looks like a really prominent medullary rim sign to me and if there are no other clinical paramaters to suggest kidney disease, it’s likely incidental or perhaps represents past renal insult.
I see this in diabetics
I see this in diabetics almost always and always attributed it to glucosuria in them but in non diabetics I think it has been considered an incidental finding like medullary rim in cats that usually means nothign or looks really pretty in FIP cats for example.. I also in shihtzus and toy breeds that often mineralize. I would check proteinuria/glucosuria and inflammatory sediment, note it, but I don’t have a specific answer here. Anyone else?
Thanks for the info on
Thanks for the info on “kidney sweat. Was the US done before fluid therapy?
Hi Remo,
There was no fluid
Hi Remo,
There was no fluid therapy prior to ultrasound. She did have intravenous fluids a month ago when she had HGE.
So cannot blame excessive
So cannot blame excessive fluids, most likley incidental but would be an idea to do a full urinalysis and to monitor renal function.