added value of diffusion-weighted mr imaging to non-enhanced ct in the evaluation of acute appendicitis

Background: although non-enhanced ct (nect) can be applied for the diagnosis of acute appendicitis in obligatory conditions such as impaired renal function, it is not as effective as contrast-enhanced ct. objectives: this prospective study aims to determine the added value of diffusion weighted imaging (dwi) in the diagnosis of acute appendicitis when combined with non-enhanced computed tomography (nect). patients and methods: between june 2014 and january 2017, 94 patients (48 male, 46 female) imaged with nect and dwi for acute appendicitis were enrolled in this prospective study. dwi was obtained with b factors 0, 500 and 1000 s/mm², and assessed with visual and quantitative analysis. results of nect and dwi, and combined imaging (nect and dwi) were analyzed by means of sensitivity, specificity and accuracy. results: nect and dwi provided 91.5% - 94.3% sensitivity, 82.6% - 86.9% specificity and 89.3% - 92.5% accuracy, respectively. the combined protocol (nect and dwi) revealed 98.5% sensitivity, 95.8% specificityand 97.8% accuracy. the addition of dwi to nect provided a 7%, 13.2% and 8.5% increase in the sensitivity, specificity and accuracy, respectively. this increase was statistically significant (p < 0.05). conclusion: dwi is an efficient technique for the diagnosis of acute appendicitis. this even may become more efficient if added to a nect scan. we recommend using dwi when nect is inevitable for different reasons. it may increase the diagnostic accuracy of nect to avoid an additional contrast-enhanced ct scan.