title: Improved artery-vein separation with acceleration-dependent preparation for non-contrast-enhanced magnetic resonance angiography.
abstract: OBJECTIVE
  To compare the use of acceleration-dependent and velocity-dependent flow-preparation for non-contrast-enhanced magnetic resonance angiography (NCE-MRA), investigating both image quality and the ability to discriminate between arteries and veins. We develop an acceleration-dependent NCE-MRA method known as acceleration dependent vascular anatomy for non-contrast-enhanced MRA (ADVANCE-MRA).
  
  
  METHODS
  Acceleration-dependent and velocity-dependent images were acquired using a constant and pulsatile flow-phantom and from the lower legs of six healthy volunteers and one patient with peripheral vascular disease. The volunteer images were assessed both by quantitative signal measurements and qualitative scoring by a radiologist.
  
  
  RESULTS
  In the phantom, acceleration-dependent preparation depicted pulsatile but not constant flow, while velocity-dependent preparation depicted both. In the volunteers and the patient, the velocity-dependent preparation was unable to separate the arterial and venous signals completely, with some overlap of arterial and venous signals for all acquired flow sensitizations whereas the acceleration-dependent preparation gave complete artery-vein separation over a wide range of flow sensitizations. Acceleration-dependent preparation received the best overall qualitative scores for arterial image quality and venous contamination.
  
  
  CONCLUSIONS
  Acceleration-dependent NCE-MRA improves arterial image quality and reduces venous contamination, compared with velocity-dependent NCE-MRA, and warrants further investigation in patients.
authors.affiliation: Department of Radiology, Addenbrooke's Hospital, Cambridge, United Kingdom.
authors.forename: Andrew Nicholas
authors.initials: AN
authors.lastname: Priest
authors.forename: Valentina
authors.initials: V
authors.lastname: Taviani
authors.forename: Martin John
authors.initials: MJ
authors.lastname: Graves
authors.forename: David John
authors.initials: DJ
authors.lastname: Lomas
mesh_terms: D000054:Acceleration; D015901:Angiography, Digital Subtraction; D001783:Blood Flow Velocity / Q000502:physiology; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D018810:Magnetic Resonance Angiography / Q000379:methods*; D016491:Peripheral Vascular Diseases / Q000503:physiopathology*; D019047:Phantoms, Imaging; D011673:Pulsatile Flow / Q000502:physiology
keywords: MRA; acceleration; non-contrast-enhanced MR angiography; velocity