title: Flow artifact in the anterior communicating artery resembling aneurysm on the time of flight MR angiogram.
abstract: BACKGROUND
  Magnetic resonance angiogram (MRA) of the brain is a widely employed non-invasive test to diagnose aneurysms. However, its overall accuracy is less than digital subtraction angiography and is prone to give false-positive or false-negative results. False-negative results can be seen with hemorrhage, lipoma, dermoid, posterior lobe of the pituitary gland, and the flow artifacts.
  
  
  OBJECTIVE
  To describe the findings associated with false aneurysms in the anterior communicating artery on the time of flight MRA and review the physical principles behind this artifact.
  
  
  METHODS
  This short series comprises of four patients whose MRA showed suspicious aneurysms in the region of the anterior communicating artery (ACOM) on time of flight MRA.
  
  
  RESULTS
  Two patients underwent catheter angiogram and the other two patients had computed tomography angiogram. None of these cases proved to have aneurysms and normal anterior communicating arteries were seen in all the patients. The findings on the MR angiograms were considered artifacts. All of the pseudoaneurysm had tapered appearance.
  
  
  CONCLUSIONS
  MR angiogram can result in artifacts at ACOM which may be mistaken for aneurysm. Such pseudoaneurysms have characteristic appearance and should be followed up with non-invasive tests.
authors.affiliation: Department of Radiology, University of Massachusetts Medical School, UMass Memorial Hospital, Worcester, MA, USA deepak.takhtani@umassmemorial.org.
authors.forename: Deepak
authors.initials: D
authors.lastname: Takhtani
authors.affiliation: Department of Radiology, University of Massachusetts Medical School, UMass Memorial Hospital, Worcester, MA, USA.
authors.forename: Sathish
authors.initials: S
authors.lastname: Dundamadappa
authors.affiliation: Department of Radiology, University of Massachusetts Medical School, UMass Memorial Hospital, Worcester, MA, USA.
authors.forename: Ajit S
authors.initials: AS
authors.lastname: Puri
authors.affiliation: Department of Radiology, University of Massachusetts Medical School, UMass Memorial Hospital, Worcester, MA, USA.
authors.forename: Ajay
authors.initials: A
authors.lastname: Wakhloo
mesh_terms: D000328:Adult; D017541:Aneurysm, False / Q000175:diagnosis*; D015901:Angiography, Digital Subtraction / Q000379:methods; D016477:Artifacts; D002533:Cerebral Angiography / Q000379:methods; D002536:Cerebral Arteries / Q000000981:diagnostic imaging / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D002532:Intracranial Aneurysm / Q000175:diagnosis*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods
keywords: Magnetic resonance angiography (MRA); anterior communicating artery (ACOM); artifact; pseudoaneurysm; turbulent flow