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Hydronephrosis

 7/22/2011  - This week we had two great images of hydronephrosis – one by Dr. Stephanie Kahn, EM PGY2 and the second by Dr. Podolsky, EM PGY1. Both patient presentations involved acute onset flank pain. In the work up, bedside US was used to further evaluate for suspected pathology. 

The below images show the kidney in long-axis. Note the large echo-free area in the echogenic renal pelvis. Both images capture moderate degrees of hydronephrosis – as commonly seen in obstructive uropathy. Dr. Kahn and Dr. Podolsky went one step further by using Doppler imaging to show the echo-free area of the renal pelvis was not vascular in origin (absence of color flow); rather, representative of urinary dilation of the renal pelvis. 

iow hydro

iow hydro2

US does not commonly detect renal stones, rather it has excellent ability to detect hydronephrosis (see below schematic representation for the degrees of hydronephrosis).

spectrum of hydro

The presence of unilateral hydronephrosis or hydroureter in the setting of hematuria and acute flank pain is very sensitive for the presence of a ureteral stone. Comparison between R and L kidneys should always be done. See the attached cartoon representation for visual reference of the degrees of hydronephrosis.  

Thanks for all your great images this week.