Fig. 1

Neuroradiological findings. Patient 1: A, D magnetic resonance imaging (MRI) examination. A, B Sagittal and coronal contrast-enhanced T1-weigthed images depict SS (red arrows) and right TS (yellow arrows) extensive thrombosis with filling defect inside the vessels. C Phase-contrast MRI angiography (PCA) with volume rendering technique shows lack of venous flow in SS (red arrow) and right TS (yellow arrow). D Susceptibility-weighted (SWI) follow-up MRI examination shows acute bilateral cerebellar hemisphere hematoma, prevalent on the right side (asterisk). Patient 2: E, H brain computed tomography (CT scan examination) at clinical onset. E Coronal unenhanced CT scan depicts large right parietal hematoma and ipsilateral TS hyperdensity (“Dense clot Sign”), indicated by yellow arrow. F Coronal enhanced CT scan shows lack of opacization of thrombosed right TS (yellow arrow). G Coronal unenhanced CT scan depicts right temporal hematoma (asterisk) and “Dense clot Sign” at SSS (blue arrow). H Coronal enhanced CT scan shows triangular area of enhancement with a relatively low-attenuating center (“Empty delta Sign”) at thrombosed SSS (blue arrow). Straight sinus (SS), superior sagittal sinus (SSS), transverse sinus (TS)