Unenhanced Multi-Detector Low-Dose vs Standard-Dose Computed Tomography in Patients Having Urinary Tract Calculi. A Practical Approach in Optimizing Patient's Dose, Experience at Jinnah Postgraduate Medical Center, Karachi
Keywords:
Urinary tract calculi, Optimized Radiation, Unenhanced Low-dose and Standard-dose CTAbstract
Objective: This study is designed to assess the diagnostic accuracy of Low-dose unenhanced multi detector computed tomography (MDCT) in patients with suspected urinary tract calculi taking Standard-dose unenhanced MDCT as gold standard.
Methods: The cross-sectional study was conducted from July to December 2016 among patients with suspected urinary tract calculi. The patients underwent unenhanced low-dose MDCT scan with reconstruction slice thickness, 7.0 mm; pitch= 1.00; tube potential 120kV; and tube charge per gantry rotation, 25-50 m As, followed by standard-dose computed tomography (CT) scan. Diagnostic accuracy of unenhanced low dose multi-detector computed tomography was calculated taking standard dose MDCT as gold standard.
Results: Out of total 50 adult patients, 32 (64%) were males and 18 (36%) were females. The mean age of the patients was 50 ± 11 years. The diagnostic accuracy of Low dose CT showed 100% sensitivity when compared with Unenhanced Standard dose CT in diagnosing urinary tract calculi, indirect signs of obstruction and adjacent organs. However, a difference was observed in blood vessels within the renal sinus which were seen in 48 kidneys in low dose CT and 49 in standard dose CT (True positive 96%, true negative 100%).
Conclusion: Low dose MDCT can be effectively used for the evaluation of urinary tract calculi with significantly decrease radiation dose to the patients compared with standard dose CT. This is due to the improvements in CT technology which allow isotropic resolution with faster scan coverage in a single, short breath-hold, and high diagnostic performance.
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