Extrarenal pelvis refers to the presence of the renal pelvis outside the confines of the renal hilum. It is a normal variant that is found in ~10% of the population 2.
The renal pelvis is formed by all the major calyces. An extarenal pelvis usually appears dilated giving a false indication of an obstructive pathology. Subsequent investigation with CT, usually clarifies the false interpretation on ultrasound.
- a normal extrarenal pelvis will demonstrate normal renal cortical thickness, bilateral symmetrical contrast excretion and normal appearing calyces 3
- 1. Dunnick R, Sandler C, Newhouse J. Textbook of Uroradiology. Lippincott Williams & Wilkins. (2012) ISBN:1451109164. Read it at Google Books - Find it at Amazon
- 2. Brant WE, Helms CA. Fundamentals of Diagnostic Radiology. Lippincott Williams & Wilkins. (2007) ISBN:0781761352. Read it at Google Books - Find it at Amazon
- 3. Siegel MJ. Pediatric body CT. Lippincott Williams & Wilkins. ISBN:078177540X. Read it at Google Books - Find it at Amazon