title: Tractography in the clinics: Implementing a pipeline to characterize early brain development.
abstract: In imaging studies of neonates, particularly in the clinical setting, diffusion tensor imaging-based tractography is typically unreliable due to the use of fast acquisition protocols that yield low resolution and signal-to-noise ratio (SNR). These image acquisition protocols are implemented with the aim of reducing motion artifacts that may be produced by the movement of the neonate's head during the scanning session. Furthermore, axons are not yet fully myelinated in these subjects. As a result, the water molecules' movements are not as constrained as in older brains, making it even harder to define structure using diffusion profiles. Here, we introduce a post-processing method that overcomes the difficulties described above, allowing the determination of reliable tracts in newborns. We tested our method using neonatal data and successfully extracted some of the limbic, association and commissural fibers, all of which are typically difficult to obtain by direct tractography. Geometrical and diffusion based features of the tracts are then utilized to compare premature babies to term babies. Our results quantify the maturation of white matter fiber tracts in neonates.
authors.affiliation: Childrens Hospital Los Angeles, Neurosurgery, 1300 Vermont Ave, Los Angeles, CA, USA; Universidad de Barcelona, Facultad de Medicina, Casanova 43, Barcelona, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Yepes-Calderon
authors.affiliation: Children Hospital Los Angeles, Radiology, 4650 Sunset Blvd, Los Angeles, CA, USA.
authors.forename: Yi
authors.initials: Y
authors.lastname: Lao
authors.affiliation: Parietal Research Team, INRIA Saclay le-de-France, Neurospin, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Fillard
authors.affiliation: Children Hospital Los Angeles, Radiology, 4650 Sunset Blvd, Los Angeles, CA, USA.
authors.forename: Marvin D
authors.initials: MD
authors.lastname: Nelson
authors.affiliation: Children's Hospital of Pittsburgh, 4401 Penn Avenue Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Ashok
authors.initials: A
authors.lastname: Panigrahy
authors.affiliation: Children Hospital Los Angeles, Radiology, 4650 Sunset Blvd, Los Angeles, CA, USA.
authors.forename: Natasha
authors.initials: N
authors.lastname: Lepore
mesh_terms: D016880:Anisotropy; D001921:Brain / Q000000981:diagnostic imaging* / Q000254:growth & development*; D001931:Brain Mapping; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007223:Infant; D008297:Male; D009434:Neural Pathways / Q000000981:diagnostic imaging* / Q000254:growth & development; D012044:Regression Analysis
keywords: CNR; DTI; Fiber tracking; Neonates; SNR; Template; Tensor registration; Tensor rotation; Tractography; Wrapped fibers