title: Persistent hypoglossal artery arising from the external carotid artery diagnosed by MR angiography.
abstract: OBJECTIVE
  Extremely rarely, a persistent hypoglossal artery arises from the external carotid artery; only three cases have been reported in the English-language literature. The purpose of this paper is to report a case of this variation diagnosed by magnetic resonance (MR) angiography.
  
  
  METHODS
  A 75-year-old man with sudden-onset right hemiparesis and dysarthria underwent emergency cerebral MR imaging and cerebral MR angiography that included the cervical carotid bifurcation. A 1.5-T scanner was used and MR angiographic images were obtained using the standard three-dimensional time-of-flight technique.
  
  
  RESULTS
  On MR angiography, an anomalous artery arose from the proximal right external carotid artery, ascended just like the ascending pharyngeal artery, entered the hypoglossal canal (anterior condyloid foramen), and finally connected with the terminal segment of the right vertebral artery (VA). The proximal right VA was not visible, probably due to hypoplasia.
  
  
  CONCLUSIONS
  We present the first case of this anomaly diagnosed using MR angiography, and we propose the term "type 2 persistent hypoglossal artery" to describe this condition.
authors.affiliation: Department of Diagnostic Radiology, Saitama Medical University International Medical Center, 1397-1 Yamane, Hidaka, Saitama 350-1298, Japan. auchino@saitama-med.ac.jp
authors.forename: Akira
authors.initials: A
authors.lastname: Uchino
authors.forename: Naoko
authors.initials: N
authors.lastname: Saito
mesh_terms: D000368:Aged; D002342:Carotid Artery, External / Q000002:abnormalities* / Q000000981:diagnostic imaging; D004636:Emergency Service, Hospital; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D010291:Paresis / Q000175:diagnosis / Q000209:etiology; D011859:Radiography; D035583:Rare Diseases; D014059:Tongue / Q000098:blood supply; D054079:Vascular Malformations / Q000150:complications / Q000175:diagnosis*; D014711:Vertebral Artery / Q000002:abnormalities / Q000000981:diagnostic imaging