Answers to Epilogue questions

### Question 1: C Unenhanced CT examination of the brain revealed extensive thrombosis in the superior sagittal, straight and left transverse sinuses (figure 1). The CT angiogram (figure 2) confirmed venous thrombosis and an arterial infarct. It revealed complete occlusion of left internal carotid artery and segmental vasculopathy, affecting multiple intracranial and extracranial vessels of both the anterior and posterior circulation along with an aneurysmal ascending aorta. The contrast-enhanced CT scan demonstrated a filling defect of the superior sagittal sinus with minimal peripheral contrast enhancement, known as the ‘empty delta sign’.1 It is a useful radiological …