title: Feasibility of interactive magnetic resonance imaging of moving anatomy for clinical practice.
abstract: BACKGROUND
  Real-time magnetic resonance imaging (MRI) imaging with real-time reconstruction has been available for some time. The technique acquires and presents the MRI images to the operator the instant they are acquired. However, besides guiding purposes, like catheter tracking and placement of electrodes during neurosurgery, the diagnostic value of this method is relatively unexplored.
  
  
  OBJECTIVE
  To test an interactive slice-positioning system with respect to real-time MRI reconstruction for imaging of moving anatomical structures on two different scanner brands by using inexpensive computer hardware.
  
  
  METHODS
  The MRI data were sampled using two acquisition schemes: a Cartesian sampling scheme and a radial sampling scheme based on the golden ratio. Four anatomical targets, which exhibit non-periodic movement, were identified and imaged: movement of the gastric ventricle emptying, movement of the small bowels, the articulators of a professional singer and of a 20-week old fetus.
  
  
  RESULTS
  Informative anatomical images were obtained in different settings of moving targets. The implemented real-time system acquired, reconstructed and displayed MRI images in real time with a high frame rate using inexpensive computer hardware on two standard 1.5 T clinical MRI scanners.
  
  
  CONCLUSIONS
  Our approach verified that when imaging selected moving anatomical targets, with no a priori knowledge of the movement, interactive slice positioning using real-time reconstruction may be a feasible approach for finding the optimal slice position in cases in which a standard 3D volumetric scan is impeded by movement. Future studies are needed to explore its full potential.
authors.affiliation: Department of Procurement & Clinical Engineering, Region Midt, Aarhus N, Denmark; MR Research Centre, Aarhus University Hospital, Skejby, Aarhus N, Denmark.
authors.forename: Lau
authors.initials: L
authors.lastname: Brix
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Sørensen
authors.forename: Yasmina
authors.initials: Y
authors.lastname: Berber
authors.forename: Mario
authors.initials: M
authors.lastname: Ries
authors.forename: Brian
authors.initials: B
authors.lastname: Stausbøl-Grøn
authors.forename: Steffen
authors.initials: S
authors.lastname: Ringgaard
mesh_terms: D001696:Biomechanical Phenomena; D005240:Feasibility Studies; D005260:Female; D005324:Fetal Movement; D005746:Gastric Emptying; D005865:Gestational Age; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007421:Intestine, Small / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D009068:Movement; D010614:Pharynx / Q000502:physiology*; D010699:Phonation; D011237:Predictive Value of Tests; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods*; D013997:Time Factors; D014831:Voice
keywords: GRAPPA; SENSE; golden ratio sampling; real-time magnetic resonance imaging; real-time reconstruction