Rim sign (chronic hydronephrosis)
The rim sign can be seen in association with chronic hydronephrosis.
In patients with chronic hydronephrosis, in all forms of contrast-enhanced imaging of the obstructed kidney, enhancement may occur in the residual, but markedly atrophic, renal parenchyma, surrounding the dilated calyces and renal pelvis 1,2.
The inner margin of this hydronephrotic rim is concave toward the renal hilum, and enhancement of the cortical columns between the dilated collecting system elements may be seen. The unopacified urine within the dilated system may act as a negative pyelogram.
Other rim signs in radiology:
- 1. Dyer RB, Chen MY, Zagoria RJ. Classic signs in uroradiology. Radiographics. 2004;24 Suppl 1 (suppl 1): S247-80. doi:10.1148/rg.24si045509 - Pubmed citation
- 2. Burgener FA, Kormano M. Differential Diagnosis in Conventional Radiology. Thieme Publishing Group. (1991) ISBN:3136561023. Read it at Google Books - Find it at Amazon
- 3. Weissleder R, Wittenberg J, Harisinghani MG et-al. Primer of diagnostic imaging. Mosby Inc. (2007) ISBN:0323040683. Read it at Google Books - Find it at Amazon