[Clinical implications of shear wave ultrasound elastography for evaluation of urinary stones].

INTRODUCTION: Currently, extracorporeal shock wave lithotripsy (ESWL) is a minimally invasive treatment for patients with urolithiasis. With advancing medical technology, elastography has evolved as a method for measuring the elasticity of tissues.

AIM: To investigate the elasticity of urinary stones for assessing their physical and chemical composition.

MATERIALS AND METHODS: The elasticity of urinary stones was determined before ESWL in 30 urolithiasis patients (18 men and 12 women, aged 25-65 years) using shear wave ultrasound elastography (SWUE). In 40%, 23.3% and 20% of patients, urinary stones were located in the renal pelvis, the middle calyceal group and the lower calyceal group, respectively.

RESULTS: Elastography is a method of determining the elasticity of urinary stones, measured in kPa. Mean elasticity (Emean) of calcium oxalate monohydrate stones, uric acid stones and mixed urinary stones was 39.8, 14.6 and 26.3-29.8 kPa, respectively. Urinary stones smaller than 5 mm did not differ in the color spectrum. Excess body mass index (BMI) also reduced the informative value of the method.

CONCLUSIONS: The findings of SWUE are comparable with the results of computer densitometry and physical and chemical composition of the investigated urinary stones.