Efficiency of diffusion-weighted MRI for differentiating radiologically similar simple and type I hydatid cysts of the liver

Background Determining the nature of purely cystic hepatic lesions is essential because different kinds have different follow-ups, treatment options, and complications. Purpose To explore the potential of apparent diffusion coefficient (ADC) values of diffusion-weighted imaging (DWI) for the differentiation of type I hydatid cysts (HC) and simple liver cysts (SLC), which have similar radiological appearances. Material and Methods This single-center prospective study was conducted during 2016-2019. Round, homogenous, anechoic liver cysts >1 cm were classified according to at least two years of imaging follow-up, radiological features, serology, as well as puncture aspiration injection reaspiration procedure and pathology results. ADC values of 95 cysts (50 type I HCs and 45 SLCs) were calculated on DWI. The differences in ADC values were analyzed by independent t-test. Results Of 51 patients, 28 were female, 23 were male (mean age 32.07 +/- 22.95 years; age range 5-82 years). Mean diameter of 45 SLCs was 2.59 +/- 1.23 cm (range 1.2-7.6 cm) and ADC(mean) value was 3.03 +/- 0.47 (range 2.64-5.85) while mean diameter of 50 type I HCs was 7.49 +/- 2.95 cm (range 2.8-14 cm) and ADC(mean) value was 2.99 +/- 0.29 (range 2.36-3.83). There was no statistically significant difference in ADC values between type I HCs and SLCs Conclusion Some studies report that ADC values of type I HCs are statistically significantly lower than those of SLCs. Others suggest no significant difference. In our study with a higher number of cases, using ADC parameters similar to those in previous studies, we did not find any statistically significant difference.