title: Distribution of intravoxel incoherent motion MRI-related parameters in the brain: evidence of interhemispheric asymmetry.
abstract: OBJECTIVE
  To compare intravoxel incoherent motion (IVIM) magnetic resonance imaging (MRI)-derived true diffusion (D) and perfusion fraction (f)-values of the two hemispheres to detect the presence of asymmetrical differences.
  
  
  METHODS
  Forty-seven healthy right-handed volunteers were assessed using IVIM imaging. The interhemispheric D- and f-values were compared using paired t-tests and two related-samples Wilcoxon's test.
  
  
  RESULTS
  Comparison of the interhemispheric D- and f-values of the grey matter revealed a significant difference in the D-value of the frontal lobe and the f-value of the temporal lobe (p=0.028, p=0.030, respectively). A significant difference in the D-values of the frontal, temporal, and occipital lobes (p=0.003, p=0.005, and p=0.001, respectively) was seen, whereas no significant difference in f-values was seen.
  
  
  CONCLUSIONS
  The distribution of the IVIM-derived D- and f-values in the two hemispheres was not completely symmetrical. Radiologists should consider this difference when the contralateral region is used as internal reference to normalise the IVIM imaging results. Average values of the interhemispheric white matter within the same lobe as the lesion may be the best internal reference.
authors.affiliation: Department of Medical Imaging Center, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, Guangdong, China.
authors.forename: C
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Medical Imaging Center, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, Guangdong, China.
authors.forename: D
authors.initials: D
authors.lastname: Ren
authors.affiliation: School of Biomedical Engineering, Southern Medical University, Guangzhou, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Guo
authors.affiliation: Department of Medical Imaging Center, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, Guangdong, China. Electronic address: wch781216@163.com.
authors.forename: Y
authors.initials: Y
authors.lastname: Xu
authors.affiliation: School of Biomedical Engineering, Southern Medical University, Guangzhou, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Feng
authors.affiliation: Department of Medical Imaging Center, The Third Affiliated Hospital, Southern Medical University, Guangzhou, 510630, Guangdong, China.
authors.forename: X
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Philips Healthcare, Guangzhou, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Mei
authors.affiliation: School of Biomedical Engineering, Southern Medical University, Guangzhou, China.
authors.forename: M
authors.initials: M
authors.lastname: Chen
authors.affiliation: Department of Medical Imaging Center, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, Guangdong, China.
authors.forename: X
authors.initials: X
authors.lastname: Xiao
mesh_terms: D000328:Adult; D054022:Cerebrum / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D056324:Diffusion Tensor Imaging / Q000379:methods*; D019317:Evidence-Based Medicine; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods*; D009038:Motion; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D066127:White Matter / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*