Bilateral ACA infarct as shown on CT and MR (T2, FLAIR, T1, ADC and DWI. This is most likely to be secondary to variation in the formation of anterior aspect of circle of Willis.
Bilateral ACA infarct is rare. The most common cause of bilateral ACA infarct is spasm in acute SAH. The other causes would include azygoud ACA, bihemishpheric ACA, and embolism or thrombus in A1 segment with hypoplasia or aplasia of contralateral A1.
Yamaguchi K et al. Bilateral Anterior Cerebral Artery Territory Infarction Associated with Unilateral Hypoplasia of the A1 Segment: Report of Two Cases. Radiation Medicine: Vol. 22 No. 6, 422–425 p.p., 2004