Fig 2. CT/CTA and MR imaging/MRA of a left ICA dissection provide similar information about vessel morphology, but MR imaging is deemed superior for making the diagnosis, particularly because of detection of acute stroke. A, Axial T1-weighted fat-suppressed image demonstrates a crescent sign around the left ICA (arrow). B, CTA curved planar reformat shows irregularity and thickening of the left ICA wall with calcified plaque. These findings are not specific for dissection and could be due to atherosclerosis. C, Contrast-enhanced MRA MIP reformat demonstrates the similar appearance of the irregular left ICA. D and E, Noncontrast CT (D) does not show the acute infarct, which is clearly identified in the left middle cerebral artery–anterior cerebral artery watershed territory on DWI (E).