52 year-old male with history of known nephrolithiasis and recurrent renal colic and obstructing stones presented with right flank pain. The pain was moderately severe with radiation to the groin and associated with subjective decreased in urine output. The patient was experiencing nausea without vomiting and denied fever or chills. Bedside ultrasound was preformed and showed the following:

Case Conclusion:

The patient's ultrasound showed moderate hydronephrosis and no bladder jet was visualized from the right ureter, consistent with the diagnosis of an obstructing renal stone. The patient's urine showed no evidence of infection and his renal function was at baseline, but given his significant history of requiring intervention for ureteral stones, a CT was obtained. The CT confirmed a 15 mm obstructing stone in the right mid ureter with moderate-severe hydroureteronephrosis, as well as multiple additional bilateral nonbstructing renal calculi. The patient's pain was able to be controlled with oral medications and he was discharged home to follow up with urology in the next 2 weeks.

Hydonephrosis:

Seen on ultrasound as replacement of the usual hyperechoic fat within the renal pelvis with anechoic fluid (urine).

Grading of hydonephrosis:

Mild: minimal separation of the renal sinus
Moderate: greater separation of the sinus with calyceal distention
Severe: marked dilation of the collection system with parenchymal thinning

In addition to evaluating the kidneys for signs of hydronephrosis, looking at the bladder for the presence of ureteral jets is also useful. In a well hydrated patient without ureteral obstruction, bladder jets may be seen using color flow doppler to look for the movement of urine from the trigone into the bladder. While even normal patients may not display jets for several minutes at a time, seeing a jet from the side of interest indicates that urine is continuing to flow from the kidney into the bladder.

-Allison Zanaboni, MD, Emergency Medicine Ultrasound Fellow