Fig. 1

a, b Axial noncontrast head computed tomography (CT) scan on presentation showing effacement of the basal cisterns (a) and a right convexity acute subdural hematoma causing midline shift (b). c Axial CT scan immediately following right hemicraniectomy and ventriculostomy placement showing relief of mass effect and evacuation of hematoma. d Three-dimensional CT angiography reconstruction showing patent posterior arterial and deep venous circulation. e, f T2-weighted magnetic resonance axial (e) and sagittal (f) images of the cervical spine 18 h postoperatively. The flow void of the basilar artery is visualized at the mid-pons, and a right temporal contusion is evident (e). The sharp transition at the pontomesencephalic junction (arrow) highlights hyperattenuation of the midbrain and diencephalon (f), with sparing of the remainder of the brainstem