Fig. 2

Case 19: 78-year-old male, arrived within 30 min of symptom onset of a right-side MCA stroke. Initial NIHSS score of 2 points. a CTA interpreted as normal by the neuroradiologist on call; the red arrow demonstrates a short right terminal carotid occlusion. b CTA demonstrates symmetrical filling of both MCA territories, which may be due to collateral flow. c DWI showing small insular ischemic changes. d TCD at the beginning of thrombolysis demonstrates a middle cerebral artery with good flow velocity but with low pulsatility index suggesting post-stenotic flow and a proximal vascular lesion. e Occlusion of right terminal carotid as revealed by the TCD. f Inverted, high velocity flow in the right anterior cerebral artery compatible with anterior cross filling (collateral flow) [33]