CT KUB evaluation of suspected urolithiasis

CT KUB in suspected urolithiasis

Abstract

Introduction: Non-contrasted computed tomography scan for kidney, ureter, and bladder (CT KUB) for the diagnosis of urolithiasis is important for accurate diagnosis, followup, and management. Unlike USG, CT KUB has more diagnostic yield in urolithiasis and other incidental findings. This study aims to evaluate the use of the CT KUB in suspected urolithiasis, which is presented with severe flank pain.

Method: A retrospective observational study was carried out in the Department of Radiology and Imaging, Patan Hospital, Nepal. The CT KUB reports of patients with suspected urolithiasis from a period of 3 years from Jan 2017 to Jan 2020 were analyzed for evidence of urolithiasis and secondary signs of obstruction as ‘diagnostic’ of CT KUB. Other incidental radiological findings were further analysed and categorized into urinary and extra-urinary. Ethical approval was obtained. The association between USG and CT KUB was analysed using the Chi-square test, with a p value of 0.05 considered statistically significant.

Result: A total of 414 CT KUB reports were analysed, 230(55.6%) males, 314 patients had USG before CT KUB. Considering CT KUB as a gold standard for the diagnosis of urolithiasis, the accuracy of ultrasound was found to be 85.03%, and sensitivity is 94.09% and specificity of 27.9%.

Conclusion:  The majority of the patients included in the study had ultrasound done before CT KUB. The sensitivity of ultrasound was significant considering CT KUB as a gold standard in the diagnosis of urolithaisis.

Keywords: Urolithiasis, CT KUB, incidental findings, USG scan