The value of diffusion-weighted imaging and apparent diffusion coefficient quantification in the diagnosis of perforated and nonperforated appendicitis.

Purpose: We aimed to evaluate the effectiveness of diffusion-weighted magnetic resonance imaging (DW-MRI) and apparent diffusion coefficient (ADC) values in the diagnosis of acute appendicitis and differentiation of perforated and nonperforated appendicitis cases, with histopathologic correlation.

Materials And Methods: Sixty consecutive patients (34 males, 26 females; mean age, 35.6±15.5 years; range, 17-83 years) with a presumptive diagnosis of acute appendicitis were included in this prospective study. With a 1.5 Tesla MRI unit, DW-MRI examinations were performed with b values of 50, 400, and 800 s/mm(2). The mean ADC values of case and control groups, as well as in perforated and nonperforated groups were compared.

Results: Of the 60 cases, 44 had a radiological diagnosis of acute appendicitis, and 16 were regarded as normal. Of the 40 patients who underwent surgical operation, 12 had a histopathological diagnosis of perforated appendicitis, and 28 had nonperforated appendicitis. Mean ADC value in patients with acute appendicitis (1.01±0.26×10(-3) mm(2)/s) was lower than the control group (1.85±0.13×10(-3) mm(2)/s) (P < 0.001). Mean ADC value of the perforated group (0.79±0.19×10(-3) mm(2)/s) was lower than the nonperforated group (1.11±0.22×10(-3) mm(2)/s) (P < 0.001). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy rate of DW-MRI in the diagnosis of acute appendicitis were 97.5%, 100%, 97.5%, 100%, and 98.1%, respectively.

Conclusion: DW-MRI and ADC quantification are effective in the diagnosis of acute appendicitis, both in perforated and nonperforated cases.