Anterior cerebral artery dissection diagnosed using high-resolution MRI.

A 51-year-old man was admitted due to weakness (3/5) of the right lower extremity. Brain MRI revealed acute infarcts in the left anterior cerebral artery (ACA) territory (figure, A). Angiographic images demonstrated a stenotic lesion in the left A2 segment (figure, B and C), which high-resolution MRI revealed as a dissection (figure, D and E). Although extensive assessments were conducted, underlying arteriopathy was not found. Arterial dissection is a frequent cause of ACA infarcts (43%), and its diagnosis depends on angiographic examinations. Our case showed that high-resolution MRI might be a useful tool for diagnosis of ACA dissections that present without typical angiographic features.