title: Effect of cerebral spinal fluid suppression for diffusional kurtosis imaging.
abstract: OBJECTIVE
  To evaluate the cerebral spinal fluid (CSF) partial volume effect on diffusional kurtosis imaging (DKI) metrics in white matter and cortical gray matter.
  
  
  METHODS
  Four healthy volunteers participated in this study. Standard DKI and fluid-attenuated inversion recovery (FLAIR) DKI experiments were performed using a twice-refocused-spin-echo diffusion sequence. The conventional diffusion tensor imaging (DTI) metrics of fractional anisotropy (FA), mean, axial, and radial diffusivity (MD, D[symbol in text], D[symbol in text] together with DKI metrics of mean, axial, and radial kurtosis (MK, K[symbol in text], K[symbol in text], were measured and compared. Single image slices located above the lateral ventricles, with similar anatomical features for each subject, were selected to minimize the effect of CSF from the ventricles.
  
  
  RESULTS
  In white matter, differences of less than 10% were observed between diffusion metrics measured with standard DKI and FLAIR-DKI sequences, suggesting minimal CSF contamination. For gray matter, conventional DTI metrics differed by 19% to 52%, reflecting significant CSF partial volume effects. Kurtosis metrics, however, changed by 11% or less, indicating greater robustness with respect to CSF contamination.
  
  
  CONCLUSIONS
  Kurtosis metrics are less sensitive to CSF partial voluming in cortical gray matter than conventional diffusion metrics. The kurtosis metrics may then be more specific indicators of changes in tissue microstructure, provided the effect sizes for the changes are comparable.
authors.affiliation: Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, New York 10016, USA. alicia.yang@med.nyu.edu
authors.forename: Alicia W
authors.initials: AW
authors.lastname: Yang
authors.forename: Jens H
authors.initials: JH
authors.lastname: Jensen
authors.forename: Caixia C
authors.initials: CC
authors.lastname: Hu
authors.forename: Ali
authors.initials: A
authors.lastname: Tabesh
authors.forename: Maria F
authors.initials: MF
authors.lastname: Falangola
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Helpern
mesh_terms: D000328:Adult; D000465:Algorithms; D016477:Artifacts; D001921:Brain / Q000033:anatomy & histology*; D002555:Cerebrospinal Fluid / Q000166:cytology*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013382:Subtraction Technique; D055815:Young Adult