The sensitivity of transabdominal ultrasound in the diagnosis of ureterolithiasis

Objectives: The echographic diagnosis of renal lithiasis colic is suggested by the existence of hydronephrosis, but the certainty is given by the direct visualization of the ureteral calculus. The aim of this study is to assess the performance of ultrasound in identifying ureteral calculi compared to other imaging methods (abdominal X-ray, urography and computed tomography). Material and method: We performed ultrasonographic examination (one or multiple examinations) in 217 patients with renal colic and ureterolithiasis. The calculus was identified by abdominal radiography, urography, computed tomography or by eliminating the calculus. Results: Ureteral calculi were ultrasonographically identified in 159 of the examined patients: 121 in the initial examination, 38 in the additional reexaminations (73.27% sensitivity as compared to other imaging techniques: 48.39% for X-ray, 68.37% for urography, and 91,11% CT). Hydronephrosis was identified in 193 patients (88.94%). Four of the patients (1.84%) were diagnosed retrospectively, based on the elimination of one calculus, but none of the imaging methods had managed to identify it previously. 12.58% of the ultrasonographically identified ureteral calculi were located in the pelviureteric junction, 10.69% in the proximal ureter, 6.91% in the mid ureter, 28.93% in the distal ureter, and 40.88% in the pelviureteric junction. Conclusions: Ultrasound is a sensitive method of detecting UL in/during a renal colic and may be used as the initial imaging method in investigating these patients. The presence or absence of hydronephrosis can not be considered as a discriminatory factor for the diagnosis of ureterolithiasis.