title: Incorporation of image data from a previous examination in 3D serial MR imaging.
abstract: OBJECTIVE
  We aimed to demonstrate that follow-up scans in longitudinal examinations can be significantly accelerated by using images from previous scans as priors for constrained reconstruction.
  
  
  METHODS
  In this work, we propose a method for incorporating a prior image to improve the reconstruction of a new acquisition with considerable k-space undersampling, which contains a two-level registration scheme with non-parametric transformation, an adaptive synthesis procedure, and a constrained reconstruction with weighted total variation constraint. The performance of the method is evaluated using simulations, as well as results from volunteer and patient examinations.
  
  
  RESULTS
  In vivo experiments with both volunteers and patients show that incorporating a prior image into the constrained reconstruction produces many fewer reconstruction errors compared to the conventional reconstruction using only the highly undersampled k-space data.
  
  
  CONCLUSIONS
  The redundant information in the prior image can be efficiently adopted to improve the reconstruction quality of the new acquisition. When maintaining the image quality, higher acceleration can be achieved with the incorporation of the prior image.
authors.affiliation: Department of Radiology, Medical Physics, University Medical Center Freiburg, Breisacher Straße 60a, 79106, Freiburg, Germany. guobin.li@uniklinik-freiburg.de.
authors.forename: Guobin
authors.initials: G
authors.lastname: Li
authors.affiliation: Department of Radiology, Medical Physics, University Medical Center Freiburg, Breisacher Straße 60a, 79106, Freiburg, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Hennig
authors.affiliation: Siemens Healthcare, Erlangen, Germany.
authors.forename: Esther
authors.initials: E
authors.lastname: Raithel
authors.affiliation: Department of Radiology, Medical Physics, University Medical Center Freiburg, Breisacher Straße 60a, 79106, Freiburg, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Büchert
authors.affiliation: Siemens Healthcare, Erlangen, Germany.
authors.forename: Dominik
authors.initials: D
authors.lastname: Paul
authors.affiliation: Department of Microsystems Engineering - IMTEK, University of Freiburg, Freiburg, Germany.
authors.forename: Jan G
authors.initials: JG
authors.lastname: Korvink
authors.affiliation: Department of Radiology, Medical Physics, University Medical Center Freiburg, Breisacher Straße 60a, 79106, Freiburg, Germany.
authors.forename: Maxim
authors.initials: M
authors.lastname: Zaitsev
mesh_terms: D000465:Algorithms; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D010363:Pattern Recognition, Automated / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013382:Subtraction Technique
keywords: 3D imaging; Non-parametric registration; Previous examination; Serial MR imaging; Weighted total variation