title: Quiescent interval low angle shot magnetic resonance angiography of the extracranial carotid arteries.
abstract: OBJECTIVE
  To test the feasibility of a quiescent interval low-angle shot (QLASH) sequence for nonenhanced MR angiography (MRA) of the extracranial carotid arteries at 3 T.
  
  
  METHODS
  The extracranial carotid arteries were imaged using QLASH MRA in healthy volunteers and patients with carotid arterial disease. The impact of three gating strategies (electrocardiographic-gated, pulse-gated, ungated) was evaluated. Image quality comparisons were made with respect to two-dimensional (2D) time of flight (TOF) MRA in volunteers and patients and contrast-enhanced MRA (CEMRA) in patients. Stenoses in patients were graded.
  
  
  RESULTS
  QLASH MRA displayed the entire extent of the extracranial carotid arteries from their origins to the skull base. Electrocardiographic-gated QLASH MRA provided better image quality than pulse-gated and ungated implementations (P < 0.05) as well as 2D TOF MRA (P < 0.05). For grading of disease, QLASH MRA showed almost perfect agreement with CEMRA (Cohen's kappa = 0.86, P < 0.001) in a small cohort of patients with carotid arterial stenosis.
  
  
  CONCLUSIONS
  QLASH MRA allows for evaluation of the entire extent of the extracranial carotid arteries with an average scan time of less than 6 min and better image quality than 2D TOF. Initial clinical results in this pilot study suggest that QLASH has potential utility as a nonenhanced alternative to CEMRA.
authors.affiliation: Department of Radiology, NorthShore University HealthSystem, Evanston, Illinois, USA.|University of Chicago Pritzker School of Medicine, Chicago, Illinois, USA.
authors.forename: Ioannis
authors.initials: I
authors.lastname: Koktzoglou
authors.affiliation: Department of Radiology, NorthShore University HealthSystem, Evanston, Illinois, USA.|Department of Radiology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA.
authors.forename: Ian G
authors.initials: IG
authors.lastname: Murphy
authors.affiliation: Siemens Healthcare, Chicago, Illinois, USA.
authors.forename: Shivraman
authors.initials: S
authors.lastname: Giri
authors.affiliation: Department of Radiology, NorthShore University HealthSystem, Evanston, Illinois, USA.|Department of Radiology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA.
authors.forename: Robert R
authors.initials: RR
authors.lastname: Edelman
mesh_terms: D000328:Adult; D000368:Aged; D016477:Artifacts; D002339:Carotid Arteries / Q000000981:diagnostic imaging* / Q000473:pathology*; D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging* / Q000473:pathology*; D016893:Carotid Stenosis / Q000473:pathology; D003287:Contrast Media; D004562:Electrocardiography; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D007091:Image Processing, Computer-Assisted / Q000379:methods; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D059629:Signal-To-Noise Ratio
chemical_list: D003287:Contrast Media
keywords: MRA; QISS; QLASH; carotid; flow artifact; time of flight