Send to

Choose Destination
West J Emerg Med. 2017 Jun;18(4):559-568. doi: 10.5811/westjem.2017.04.33119. Epub 2017 May 15.

Ultrasound vs. Computed Tomography for Severity of Hydronephrosis and Its Importance in Renal Colic.

Author information

Boston University School of Medicine, Department of Emergency Medicine, Boston, Massachusetts.
Boston Medical Center, Department of Emergency Medicine, Boston, Massachusetts.
Tufts University, Friedman School of Nutrition Science and Policy, Boston, Massachusetts.
Boston University, School of Public Health, Boston, Massachusetts.
New York University School of Medicine, Department of Emergency Medicine, New York, New York.



Supporting an "ultrasound-first" approach to evaluating renal colic in the emergency department (ED) remains important for improving patient care and decreasing healthcare costs. Our primary objective was to compare emergency physician (EP) ultrasound to computed tomography (CT) detection of hydronephrosis severity in patients with suspected renal colic. We calculated test characteristics of hydronephrosis on EP-performed ultrasound for detecting ureteral stones or ureteral stone size >5mm. We then analyzed the association of hydronephrosis on EP-performed ultrasound, stone size >5mm, and proximal stone location with 30-day events.


This was a prospective observational study of ED patients with suspected renal colic undergoing CT. Subjects had an EP-performed ultrasound evaluating for the severity of hydronephrosis. A chart review and follow-up phone call was performed.


We enrolled 302 subjects who had an EP-performed ultrasound. CT and EP ultrasound results were comparable in detecting severity of hydronephrosis (x2=51.7, p<0.001). Hydronephrosis on EP-performed ultrasound was predictive of a ureteral stone on CT (PPV 88%; LR+ 2.91), but lack of hydronephrosis did not rule it out (NPV 65%). Lack of hydronephrosis on EP-performed ultrasound makes larger stone size >5mm less likely (NPV 89%; LR- 0.39). Larger stone size > 5mm was associated with 30-day events (OR 2.30, p=0.03).


Using an ultrasound-first approach to detect hydronephrosis may help physicians identify patients with renal colic. The lack of hydronephrosis on ultrasound makes the presence of a larger ureteral stone less likely. Stone size >5mm may be a useful predictor of 30-day events.

[Indexed for MEDLINE]
Free PMC Article

Conflict of interest statement

Conflicts of Interest: By the WestJEM article submission agreement, all authors are required to disclose all affiliations, funding sources and financial or management relationships that could be perceived as potential sources of bias. No author has professional or financial relationships with any companies that are relevant to this study. There are no conflicts of interest or sources of funding to declare.

Supplemental Content

Full text links

Icon for PubMed Central
Loading ...
Support Center