Comparison of standard-dose and low-dose scanning with 16-MDCT for urinary calculi / 中华放射医学与防护杂志

ABSTRACT

Objective To explore the feasibility to diagnose ureterolithiasis by 16-multidetector spiral computed tomography (16-MDCT) at different low doses based on body mass index (BMI).Methods A total of one hundred patients from 2009 Sep to 2010 Feb suspected of ureterolithiasis were randomly divided into 2 equal groups undergoing 16-MDCT at standard-dose (120 kV, 240 mA) or lowdose (120, 80, and 50 mA, respectively) based on the body mass index (BMI).Taking the clinical diagnosis as the standard, the sensitivity level, specificity level, and positive predictive value of these groups were compared.Results The dose length product ( DLP ) of the low-dose CT group and the average CT dose index (CTDIvol ) were 18.95 and 6.65 mGy, respectively.There was significant difference between the two groups ( t = 31.78, P ＜ 0.01 ).The sensitivity level, specificity level, and positive predictive value of the low-dose group were 97.1% , 94.0% , and 94.3% , respectively, all not significantly different from those of the standard-dose groups (97.3% , 96.0% , and 97.3% , respectively,P ＞0.05).Conclusions It is feasible to diagnose ureterolithiasis by low-dose 16-MDCT based on BMI with the obtained image quality meeting the clinical diagnostic requirements.