Bear paw sign (kidney)

Last revised by Dalia Ibrahim on 20 Aug 2022

Citation, DOI, disclosures and article data

Citation:

Gaillard F, Ibrahim D, El-Feky M, et al. Bear paw sign (kidney). Reference article, Radiopaedia.org (Accessed on 11 Dec 2023) https://doi.org/10.53347/rID-9946

DOI:

https://doi.org/10.53347/rID-9946

Permalink:

https://radiopaedia.org/articles/9946

rID:

9946

Article created:

1 Jun 2010, Frank Gaillard ◈

Disclosures:

At the time the article was created Frank Gaillard had no recorded disclosures.

View Frank Gaillard's current disclosures

Last revised:

20 Aug 2022, Dalia Ibrahim ◉

Disclosures:

At the time the article was last revised Dalia Ibrahim had no recorded disclosures.

View Dalia Ibrahim's current disclosures

Revisions:

12 times, by 9 contributors - see full revision history and disclosures

Systems:

Urogenital

Sections:

Signs

Tags:

refs, kidney, infection, cases

Synonyms:

Bear paw sign (xanthogranulomatous pyelonephritis)

The bear paw sign refers to the cross-sectional appearance of the kidney affected by xanthogranulomatous pyelonephritis. There is a radial arrangement of multiple, low attenuation rounded spaces representing dilated calyces, surrounded by thin renal parenchyma that has higher attenuation or contrast enhancement, mimicking the appearance of the dark toe pads on a polar bear's paw.