Susceptibility artifacts in ruptured intracranial dermoid cysts: a poorly understood but important phenomenon.

Rupture of intracranial dermoid cyst is a rare event. The classical imaging feature is described as a fat-containing lesion with tiny fat droplets in the subarachnoid or ventricular system. The lesion and the fat droplets show susceptibility blooming artifact on susceptibility-weighted images (SWI). Knowledge of this fact is important because these lesions mimic the blooming artifact of haemorrhage on SWI. The cause of the susceptibility artifact in intracranial dermoids has not been reported in the literature to date. We describe two cases of ruptured intracranial dermoids in the basifrontal region and review the clinical and imaging features and possible causes of susceptibility artifacts in intracranial dermoid cysts.