Abstract
A 46-year-old woman presented with non-traumatic anterior cerebral artery dissection manifesting as sudden onset of headache and motor weakness of the right lower limb. Angiography revealed luminal narrowing of the left anterior cerebral artery from the A3 portion to the distal portion. Sagittal T1-weighted magnetic resonance imaging showed hyperintensity due to an intramural hematoma around the flow void signal of the affected anterior cerebral artery. Sagittal magnetic resonance imaging should be performed in suspected cases of anterior cerebral artery dissection to detect the diagnostic finding of intramural hematoma.