Can the degree of hydronephrosis on ultrasound predict kidney stone size?

Am J Emerg Med. 2010 Sep;28(7):813-6. doi: 10.1016/j.ajem.2009.06.028. Epub 2010 Jan 28.


Objective: The aim of the study was to determine if the degree of hydronephrosis on focused emergency renal ultrasound correlates with kidney stone size on computed tomography.

Methods: A retrospective study was performed on all adult patients in the emergency department who had a focused emergency renal ultrasound and ureterolithiasis on noncontrast computed tomography. Severity of hydronephrosis was determined by the performing physician. Ureteral stone size was grouped into 5 mm or less and larger than 5 mm based on likelihood of spontaneous passage.

Results: One hundred seventy-seven ultrasound scans were performed on patients with ureteral calculi. When dichotomized using test characteristic analysis, patients with none or mild hydronephrosis (72.9%) were less likely to have ureteral calculi larger than 5 mm than those with moderate or severe hydronephrosis (12.4% vs 35.4%; P < .001) with a negative predictive value of 0.876 (95% confidence interval, 0.803-0.925).

Conclusion: Patients with less severe hydronephrosis were less likely to have larger ureteral calculi.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Chi-Square Distribution
  • Emergency Medicine
  • Emergency Service, Hospital
  • Emergency Treatment
  • Female
  • Humans
  • Hydronephrosis / classification
  • Hydronephrosis / diagnostic imaging*
  • Hydronephrosis / etiology*
  • Male
  • Middle Aged
  • Observer Variation
  • Predictive Value of Tests
  • Retrospective Studies
  • Risk Factors
  • Sensitivity and Specificity
  • Severity of Illness Index*
  • Tomography, X-Ray Computed
  • Ultrasonography
  • Ureterolithiasis / classification
  • Ureterolithiasis / complications*
  • Ureterolithiasis / diagnostic imaging*