Fig. 2From: Spontaneous cervicocephalic arterial dissection with headache and neck pain as the only symptomMRA and MRA source image findings in internal carotid artery dissection (case 6). a The string sign is visible in the left cervical internal carotid artery on MRA. b A double lumen is seen in the left cervical internal carotid artery on the MRA source imageBack to article page