Spatiotemporal alignment of in utero BOLD-MRI series Articles uri icon

authors

  • TURK, ESRA ABACI
  • LUO, JIE
  • GAGOSKI, BORJAN
  • PASCAU GONZALEZ GARZON, JAVIER
  • BIBBO, CAROLINA
  • ROBINSON, JULIAN N.
  • GRANT, P. ELLEN
  • ADALSTEINSSON, ELFAR
  • GOLLAND, POLINA
  • MALPICA, NORBERTO

publication date

  • August 2017

start page

  • 403

end page

  • 412

issue

  • 2

volume

  • 46

International Standard Serial Number (ISSN)

  • 1053-1807

Electronic International Standard Serial Number (EISSN)

  • 1522-2586

abstract

  • PurposeTo present a method for spatiotemporal alignment of in-utero magnetic resonance imaging (MRI) time series acquired during maternal hyperoxia for enabling improved quantitative tracking of blood oxygen level-dependent (BOLD) signal changes that characterize oxygen transport through the placenta to fetal organs. Materials and MethodsThe proposed pipeline for spatiotemporal alignment of images acquired with a single-shot gradient echo echo-planar imaging includes 1) signal nonuniformity correction, 2) intravolume motion correction based on nonrigid registration, 3) correction of motion and nonrigid deformations across volumes, and 4) detection of the outlier volumes to be discarded from subsequent analysis. BOLD MRI time series collected from 10 pregnant women during 3T scans were analyzed using this pipeline. To assess pipeline performance, signal fluctuations between consecutive timepoints were examined. In addition, volume overlap and distance between manual region of interest (ROI) delineations in a subset of frames and the delineations obtained through propagation of the ROIs from the reference frame were used to quantify alignment accuracy. A previously demonstrated rigid registration approach was used for comparison. ResultsThe proposed pipeline improved anatomical alignment of placenta and fetal organs over the state-of-the-art rigid motion correction methods. In particular, unexpected temporal signal fluctuations during the first normoxia period were significantly decreased (P < 0.01) and volume overlap and distance between region boundaries measures were significantly improved (P < 0.01). ConclusionThe proposed approach to align MRI time series enables more accurate quantitative studies of placental function by improving spatiotemporal alignment across placenta and fetal organs. Level of Evidence: 1 Technical Efficacy: Stage 1 J. MAGN. RESON. IMAGING 2017;46:403-412

keywords

  • motion correction; signal nonuniformity; bold-mri; placental mri; fetal mri; hyperoxygenation