title: Persistent dorsal ophthalmic artery and ophthalmic artery arising from the middle meningeal artery diagnosed by MR angiography at 3 T.
abstract: BACKGROUND
  A persistent dorsal ophthalmic artery (OA) is a rare variation that originates from the cavernous segment of the internal carotid artery (ICA) and enters the orbit via the superior orbital fissure (SOF). Occasionally, the OA also arises from the middle meningeal artery (MMA) and enters the orbit via the SOF. These two major variations of the OA have not been well described by magnetic resonance (MR) angiography. We evaluated their prevalence on MR angiography at 3 T.
  
  
  METHODS
  We retrospectively reviewed our database of MR angiographic images obtained using a 3 T imager. Of images of 846 patients, we evaluated those of 826 patients (1,652 OAs) with special attention to OA origin and its course into the orbit. We excluded images of the 20 because quality was insufficient to assess.
  
  
  RESULTS
  We found 7 (0.42%) persistent dorsal OAs among 1,652 OAs (right/left, 6/1; male/female, 3/4). Twenty-four (1.45%) OAs arose from the MMA (right/left/bilateral, 11/5/4; male/female, 10/10), three of which also demonstrated a small normally branching OA. In one patient, we observed both right persistent dorsal OA and left OA arising from the MMA.
  
  
  CONCLUSIONS
  Per OA, the prevalence of persistent dorsal OA was 0.42% and of OA arising from the MMA, 1.45%, with a tendency toward right-side predominance. OA arising from the MMA can be seen bilaterally; preprocedural knowledge of this variation is important because of the danger associated with endovascular procedures of the external carotid system when the OA arises from the MMA.
authors: Department of Diagnostic Radiology, Saitama Medical University International Medical Center, 1397-1 Yamane, Hidaka, Saitama, 350-1298, Japan, auchino@saitama-med.ac.jp.
authors: Akira
authors: A
authors: Uchino
authors: Naoko
authors: N
authors: Saito
authors: Masahiro
authors: M
authors: Takahashi
authors: Eito
authors: E
authors: Kozawa
authors: Waka
authors: W
authors: Mizukoshi
authors: Reiko
authors: R
authors: Nakajima
authors: Nanami
authors: N
authors: Okano
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D063405:Anatomic Variation; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D008576:Meningeal Arteries / Q000002:abnormalities*; D008875:Middle Aged; D009880:Ophthalmic Artery / Q000002:abnormalities*; D012189:Retrospective Studies; D055815:Young Adult