ICA and enters the orbit via the superior orbital ssure (SOF) instead of the OC (Fig.6.1). During early gestation, there are primitive dorsal and ventral OphAs; the dorsal OphA usually regresses, while the ventral OphA remains and forms a normal OphA.If the situation is reversed and the ventral OphA disappears and the dorsal OphA remains, this variation may be formed. Lasjaunias etal. [1] attributed this variation to a persistent dorsal OphA.The inferolateral trunk of the ICA has a tiny branch that runs towards the SOF.Should the ventral OphA regress, this tiny artery enlarges for collateral circulation and serves as an aberrant OphA that originates from the cavernous ICA.Komiyama [2] indicated this anomalous OphA should not be called a persis­tent dorsal OphA, as a dorsal OphA that persists passes through the OC rather than the SOF. Although this variation was traditionally termed “persistent dorsal OphA” [3], this name may not be adequate for this variation. Recently, this anomalous origin is believed to be due to the persistence and enlargement of the lateral branch of the primitive maxillary artery [4]. Its MR angi­ographic prevalence was reported to be 0.42% per OphA [5], and there is a tendency toward right-side predominance. Extremely rarely, it can be seen bilaterally (Fig.6.2). This type of OphA also rarely arises from the carotid siphon, distal to the usual point but proximal to the normal aris­ing point (Fig.6.3).