Fig. 2

MRA imaging. a Red arrow shows the left middle cerebral artery, green arrow shows the left anterior cerebral artery, purple arrow shows absence of the left internal carotid artery, yellow arrow shows anterior communicating artery feeding the left middle cerebral artery and anterior cerebral artery, and blue arrow shows vascular tuft being fed from the left vertebral artery. b Red arrow shows the left middle cerebral artery, green arrow shows the left anterior cerebral artery, yellow arrow shows anterior communicating artery feeding he left middle cerebral artery and anterior cerebral artery, and blue arrow shows vascular tuft being fed from the left vertebral artery. c Red arrow shows absent left internal carotid artery, green arrow shows the left anterior cerebral artery, yellow arrow shows vascular malformation in the region of quadrigeminal cistern, and blue arrows show vascular tuft being fed from the left vertebral artery. d Red arrows show tuft of serpiginous vessels in the left anterior ambient cistern, and yellow arrow shows vascular nidus in the quadrigeminal cistern