Validity of Ultrasonography for the Detection of Renal and Ureteric Calculi in Patients of Renal Colic

Abstract

Objectives: To assess the validity of ultrasonography (USG) for detection of renal and ureteric calculi in patients of renal colic by taking computerized tomography (CT) scan as a gold standard.

Methodology: This cross-sectional study was conducted at KRL General Hospital Islamabad from 1^st January 2019 to 31^st December 2019. One hundred and ten patients with suspected renal colic presenting in emergency and outpatient departments were recruited through non-probability convenience sampling. Both adult female and male patients irrespective of their age, fulfilling the inclusion criteria were included. Transabdominal USG and unenhanced CT of all patients were performed, and findings were recorded.

Results: CT scan was taken as gold standard and sensitivity, specificity, positive predictive values, negative predictive values, and diagnostic accuracy of ultrasound in detecting renal calculi were 73.08%, 94.83%, 92.68%, 79.71%, and 84.54% respectively. While these values in detecting ureteric calculi by USG were 14.81%, 89.65%, 80%, 27.37% and 34.54% respectively.

Conclusion: For diagnosing renal calculi in patients with renal colic, the diagnostic accuracy of USG is adequate, and it can be utilized as a first-line investigation, especially in children and pregnant women, where CT is contraindicated. However, USG, on the other hand, is less suitable for detecting ureteric calculi due to its limited sensitivity and specificity. USG due to its low operational expenses, economic effectiveness, ready availability, and lack of ionizing radiations justify its usage as an initial diagnostic modality, with CT reserved for cases where ultrasonography is inconclusive.