Diagnostic Accuracy of Ultrasound for the Evaluation of Ureteric Calculi Taking Non-enhanced Computed Tomography as a Gold Standard

Abstract

Objective: To find the diagnostic accuracy of ultrasound for the evaluation of ureteric calculi taking non enhanced Computed Tomography as gold standard.

Study Design: An analytical cross-sectional prospective study was performed.

Settings: The study was performed in National Hospital and Medical Center, Lahore.

Period: An analytical cross-sectional study was conducted from 15 October, 2020 to 15 January, 2021.

Material & Methods: In our study, all those patients with suspected ureteric calculi presenting to radiology department were included. Patients on dialysis, those with polycystic disease and ureteric stricture, as well as patients who declined to give consent and those who were uncooperative, were all excluded. Ultrasound was performed on both sides of the patient's kidney, concentrating on the ureters. Then were sent to a 64 slice CT scanner for a non-enhanced CT scan.

Results: Total 121 Patients were reviewed in this research. Females were 82 (67.8%) while male was 39 (32.2%). On Ultrasound 61(50.4%) were positive for ureteric calculi while 60 (49.6%) were negative for stone in the ureter. On CT scan 110 (90.9%) patients were positive for ureteric calculi while 11 (9.1%) were negative for stone in ureter (p= 0.05). The trans-abdominal ultrasound with sensitivity 58.62%, Specificity 56.76%, Positive predictive value 51.52% and Negative predictive value of 63.64% and accuracy of 57.68%.

Conclusion: The sensitivity of ultrasound is comparable to Computed Tomography findings, hence, it can be used as an option in cases where CT scans are not available or is contraindicated, such as in pregnant women. Moreover, Ultrasound modality is cheap, with no radiation dose and is readily available in our setups, making it suitable for initial diagnosis as well as for follow-up scans.

Keywords: Non-enhanced Computed Tomography, Ultrasound, Ureteric Calculi, radiation, Computed Tomography.

DOI: 10.7176/JHMN/90-04

Publication date:June 30^th 2021