title: Accelerating non-contrast-enhanced MR angiography with inflow inversion recovery imaging by skipped phase encoding and edge deghosting (SPEED).
abstract: OBJECTIVE
  To accelerate non-contrast-enhanced MR angiography (MRA) with inflow inversion recovery (IFIR) with a fast imaging method, Skipped Phase Encoding and Edge Deghosting (SPEED).
  
  
  METHODS
  IFIR imaging uses a preparatory inversion pulse to reduce signals from static tissue, while leaving inflow arterial blood unaffected, resulting in sparse arterial vasculature on modest tissue background. By taking advantage of vascular sparsity, SPEED can be simplified with a single-layer model to achieve higher efficiency in both scan time reduction and image reconstruction. SPEED can also make use of information available in multiple coils for further acceleration. The techniques are demonstrated with a three-dimensional renal non-contrast-enhanced IFIR MRA study.
  
  
  RESULTS
  Images are reconstructed by SPEED based on a single-layer model to achieve an undersampling factor of up to 2.5 using one skipped phase encoding direction. By making use of information available in multiple coils, SPEED can achieve an undersampling factor of up to 8.3 with four receiver coils. The reconstructed images generally have comparable quality as that of the reference images reconstructed from full k-space data.
  
  
  CONCLUSIONS
  As demonstrated with a three-dimensional renal IFIR scan, SPEED based on a single-layer model is able to reduce scan time further and achieve higher computational efficiency than the original SPEED.
authors.affiliation: Department of Radiation Oncology, Duke University, Durham, North Carolina 27710, USA. zheng.chang@duke.edu
authors.forename: Zheng
authors.initials: Z
authors.lastname: Chang
authors.forename: Qing-San
authors.initials: QS
authors.lastname: Xiang
authors.forename: Hao
authors.initials: H
authors.lastname: Shen
authors.forename: Fang-Fang
authors.initials: FF
authors.lastname: Yin
mesh_terms: D000465:Algorithms; D016477:Artifacts; D003198:Computer Simulation; D003287:Contrast Media; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007668:Kidney / Q000098:blood supply / Q000502:physiology*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008954:Models, Biological; D012079:Renal Circulation / Q000502:physiology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D003287:Contrast Media