ABSTRACT
BACKGROUND: Our aim was to determine whether the Apparent Diffusion Coefficient is able to predict the presence of a symptomatic pineal cyst by detecting cerebral edema. METHODS: We retrospectively analyzed MRIs of 45 patients with pineal cysts before and after resection and 51 patients without pineal cysts, comparing ADC values of thalamus, central, periventricular and subcortical white matter. Furthermore we evaluated cyst size and morphology and analyzed its correlation to ADC values in corresponding patients. RESULTS: Differences between patients with symptomatic pineal cyst and control group were not significant (p = 0.200 - 0.968). ADC ratios did not change significantly after resection of the cyst (p = 0.575 - 0.862). Cyst size showed no significant correlation to ADC ratios (p = 0.071 - 0.918). Raw data analyses revealed more significance, especially periventricularly and in central white matter, which resulted in significant interhemispheric differences in ADC ratios in both subgroups (p < 0.001 and p = 0.031). MRI of 1.5T showed consistently higher values than 3T but mostly insignificant. CONCLUSION: Our analysis revealed no evidence that pineal cysts lead to intracerebral edema caused by venous compression. Since variability was higher than the differences seen, ADC sequences do not appear to be an appropriate diagnostic tool for symptomatic pineal cysts.