Correlating Degree of Hydronephrosis on Ultrasound with Ureteric Calculus Size on Computed Tomography.

Abstract

AIM & OBJECTIVE: To correlate the degree of hydroureteronephrosis on ultrasound with ureteric stone size determined by non-contrast CT.

MATERIALS AND METHODS: This is a prospective study which was done in the period between Jan 2024 and December 2024 using ‘Samsung HS70A’ & ‘Toshiba Aquilion prime160 slice’ CT scanner. All patients with hydronephrosis secondary to ureteric calculus in ultrasound and CT underwent screening CT and USG respectively with proper consent. Hydronephrosis severity was graded on ultrasound and stone size was categorized as ≤5 mm or >5 mm based on CT.

RESULTS: Among the 112 patients, 86 had stones ≤5 mm and 26 had stones >5 mm. Increasing degree of hydronephrosis on ultrasound was associated with an increasing proportion of ureteral calculi larger than 5 mm (P < .001). Patients with none or mild hydronephrosis were less likely to have larger ureteral calculi than those with moderate or severe hydronephrosis (12.4% vs 35.4%; P < .001). An increasing degree of hydronephrosis was associated with a higher likelihood of larger stones.

CONCLUSION: There was statistically significant correlation between the degree of ultrasound detected hydronephrosis and the size of the obstructing ureteric calculus. Patients with less severe hydronephrosis are less likely to have stones >5 mm. Thus, ultrasound may help identify low-risk patients and guide imaging decisions, potentially reducing unnecessary CT scans and radiation.