Presentation
Mild headache and Horner's syndrome.
Patient Data
Crescenteric rim of high signal on the T1 FS sequence in keeping with intimal hemorrhage in the right internal carotid artery.
Compare it with the normal left side.
Associated contour irregularity of the vessel on the MRA.
Case Discussion
Carotid artery dissection is one of the less common, but important causes of stroke. It is of particular importance in those presenting with a 'stroke in the young' (under 45 years of age).
MRI is the diagnostic modality of choice. The T1 fat saturation sequence is usually the key - the intimal hemorrhage within the affected vessel shown as a high signal crescent - the crescent sign of arterial dissection.