Possibilities of dual-energy computed tomography in identification of urate kidney stones
Objective. A comparative analysis of identification of uric acid in the composition of stones by methods of dual energy computed tomography and infrared spectroscopy.
Patients and methods. We analysed the composition of 89 stones of patients with a long history of urolithiasis. The chemical composition of kidney stones in all patients was determined by DECT on a 64-slice CT scanner Discovery 750 HD (GE Healthcare) with the technology of fast switching between 80 kV кВ and 140 kV кВ. Further we employed a standard method of determining the composition of uroliths – infrared spectroscopy.
Results. Analysis of data obtained by IR spectroscopy showed that kidneys containing two components were most common, they were found in 67.1% of patients. One-component stones occurred more rarely – in 30.5% of cases, three-component uroliths were found only in 2.2% of patients. It is noteworthy that among two-component stones those containing of apatite and weddellite were most common. The urate type of a concrement, according to the findings of DECT, statistically significantly (р > 0.1) correlates with data obtained by the IRS method – in 90.5% of cases. Using ROC curve analysis we found that the greatest specificity and sensitivity in determination of CT density was found at 40 kV кВ.
Conclusion. DECT can be used for identification of urate stones at different stages of treatment of patients.
Key words: urolithiasis, urinary stone composition, dual-energy computed tomography.
For citation: Zueva L.F., Zhestovskaya S.I., Bezrukov E.А., Karlova E.A., Kapsargin F.P. Possibilities of dual-energy computed tomography in identification of urate kidney stones. Vopr. urol. androl. (Urology and Andrology). 2019; 7(3): 10-17. (In Russian). DOI: 10.20953/2307-6631-2019-3-10-17