title: Respiratory motion prediction and prospective correction for free-breathing arterial spin-labeled perfusion MRI of the kidneys.
abstract: OBJECTIVE
  Respiratory motion prediction using an artificial neural network (ANN) was integrated with pseudocontinuous arterial spin labeling (pCASL) MRI to allow free-breathing perfusion measurements in the kidney. In this study, we evaluated the performance of the ANN to accurately predict the location of the kidneys during image acquisition.
  
  
  METHODS
  A pencil-beam navigator was integrated with a pCASL sequence to measure lung/diaphragm motion during ANN training and the pCASL transit delay. The ANN algorithm ran concurrently in the background to predict organ location during the 0.7-s 15-slice acquisition based on the navigator data. The predictions were supplied to the pulse sequence to prospectively adjust the axial slice acquisition to match the predicted organ location. Additional navigators were acquired immediately after the multislice acquisition to assess the performance and accuracy of the ANN. The technique was tested in eight healthy volunteers.
  
  
  RESULTS
  The root-mean-square error (RMSE) and mean absolute error (MAE) for the eight volunteers were 1.91 ± 0.17 mm and 1.43 ± 0.17 mm, respectively, for the ANN. The RMSE increased with transit delay. The MAE typically increased from the first to last prediction in the image acquisition. The overshoot was 23.58% ± 3.05% using the target prediction accuracy of ± 1 mm.
  
  
  CONCLUSIONS
  Respiratory motion prediction with prospective motion correction was successfully demonstrated for free-breathing perfusion MRI of the kidney. The method serves as an alternative to multiple breathholds and requires minimal effort from the patient.
authors.affiliation: Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA.
authors.forename: Hao
authors.initials: H
authors.lastname: Song
authors.affiliation: Departments of Radiation Oncology, Biomedical Physics and Bioengineering, UCLA, Los Angeles, CA, 90095, USA.
authors.forename: Dan
authors.initials: D
authors.lastname: Ruan
authors.affiliation: Departments of Radiation Oncology, Biomedical Physics and Bioengineering, UCLA, Los Angeles, CA, 90095, USA.
authors.forename: Wenyang
authors.initials: W
authors.lastname: Liu
authors.affiliation: Department of Medicine, University of Hawai'i at Manoa, Honolulu, HI, 96813, USA.
authors.forename: V Andrew
authors.initials: VA
authors.lastname: Stenger
authors.affiliation: High-Field Magnetic Resonance Center, Max Planck Institute for Biological Cybernetics, 72076, Tubingen, Germany.
authors.forename: Rolf
authors.initials: R
authors.lastname: Pohmann
authors.affiliation: Department of Radiology, University of Navarra Hospital, 31008, Pamplona, Spain.
authors.forename: Maria A
authors.initials: MA
authors.lastname: Fernández-Seara
authors.affiliation: DMC R&D Center, Samsung Electronics Inc., Seocho-gu, 06765, Seoul, Korea.
authors.forename: Tejas
authors.initials: T
authors.lastname: Nair
authors.affiliation: Department of Statistics, University of Pittsburgh, Pittsburgh, PA, 15213, USA.
authors.forename: Sungkyu
authors.initials: S
authors.lastname: Jung
authors.affiliation: Department of Surgery, Washington University in St. Louis, St. Louis, MO, 63110, USA.
authors.forename: Jingqin
authors.initials: J
authors.lastname: Luo
authors.affiliation: Department of Electrical and Computer Engineering, Virginia Commonwealth University, Richmond, VA, 23284, USA.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Motai
authors.affiliation: Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA.
authors.forename: Jingfei
authors.initials: J
authors.lastname: Ma
authors.affiliation: Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA.
authors.forename: John D
authors.initials: JD
authors.lastname: Hazle
authors.affiliation: Departments of Radiation Oncology and Radiology, Washington University, St. Louis, MO, 63110, USA.
authors.forename: H Michael
authors.initials: HM
authors.lastname: Gach
mesh_terms: D000328:Adult; D003964:Diaphragm / Q000000981:diagnostic imaging / Q000502:physiology; D005260:Female; D006801:Humans; D007668:Kidney / Q000000981:diagnostic imaging* / Q000502:physiology; D008168:Lung / Q000000981:diagnostic imaging / Q000502:physiology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009038:Motion; D009068:Movement; D016571:Neural Networks, Computer; D012119:Respiration; D013113:Spin Labels; D055815:Young Adult
chemical_list: D013113:Spin Labels
keywords: arterial spin label; artificial neural network; kidney; magnetic resonance imaging; respiratory motion prediction