Article Figures & Data
Tables
- TABLE 1:
Numbers of directions and repetitions for the three pulsed gradient spin-echo echo-planar imaging pulse sequences used in the study
No. of Measurements Total No. of Images per Section No. of Diffusion Directions PGSE SS-EPI 1 10 7 6 PGSE SS-EPI 2 10 7 6 PGSE SS-EPI 3 8 9 8 Note.—PGSE SS-EPI indicates pulsed gradient spin-echo single shot echo-planar imaging. Additional information regarding the three diffusion sequences is presented in the Methods section.
- TABLE 2:
Mean diffusivity and fractional anisotropy histogram-derived metrics, averaged over the eight participants, for each of the three pulsed gradient spin-echo single shot echo-planar imaging sequences run on two different imaging units
Imaging Unit A B PGSE SS-EPI 1 Average MD (SD) [×10−3 mm2/s] 0.89 (0.01) 0.85 (0.02) Mean MD peak height (SD) 98.0 (10.5) 105.0 (7.7) Mean MD peak position (SD) [×10−3 mm2/s] 0.76 (0.02) 0.74 (0.02) Average FA (SD) 0.24 (0.011) 0.26 (0.003) Mean FA peak height (SD) 48.9 (4.5) 49.8 (1.8) Mean FA peak position (SD) 0.1 (0.001) 0.1 (0.001) PGSE SS-EPI 2 Average MD (SD) [×10−3 mm2/s] 0.91 (0.02) 0.84 (0.02) Mean MD peak height (SD) 98.8 (10.5) 112.3 (10.0) Mean MD peak position (SD) [×10−3 mm2/s] 0.76 (0.03) 0.72 (0.03) Average FA (SD) 0.22 (0.009) 0.26 (0.006) Mean FA peak height (SD) 55.2 (4.5) 45.7 (3.4) Mean FA peak position (SD) 0.1 (0.002) 0.1 (0.001) PGSE SS-EPI 3 Average MD (SD) [×10−3 mm2/s] 0.92 (0.02) 0.85 (0.02) Mean MD peak height (SD) 98.1 (11.0) 102.3 (10.6) Mean MD peak position (SD) [×10−3 mm2/s] 0.76 (0.02) 0.73 (0.03) Average FA (SD) 0.22 (0.008) 0.24 (0.010) Mean FA peak height (SD) 57.2 (5.2) 50.0 (4.14) Mean FA peak position (SD) 0.1 (0.001) 0.1 (0.001) Note.—PGSE SS-EPI indicates pulsed gradient spin-echo single shot echo-planar imaging; MD, mean diffusivity; FA, fractional anisotropy.
- TABLE 3:
Inter-sequence and inter-imaging unit mean coefficients of variation (standard error of the means) for the mean diffusivity and fractional anisotropy histogram-derived metrics
Inter-Sequence (%) Inter-Imaging Unit (%) P* Average MD 1.72 (0.14) 5.37 (0.7) 0.003 MD peak height 5.56 (0.6) 10.19 (1.0) <0.001 MD peak position 1.90 (0.2) 4.20 (0.43) <0.001 Average FA 5.45 (0.4) 7.71 (0.6) 0.002 FA peak height 7.34 (0.9) 6.07 (0.8) n.s. FA peak location 7.30 (0.6) 8.74 (0.9) n.s. Note.—MD indicates mean diffusivity; FA, fractional anisotropy; n.s., not significant.
* Statistical analysis: comparisons were conducted by using a bootstrap resampling technique.
- TABLE 4:
Inter-sequence and inter-imaging unit mean coefficients of variation (standard error of the means) for the λ1, λ2, and λ3 histogram-derived metrics
Inter-Sequence (%) Inter-Imaging Unit (%) P* Average λ1 1.63 (0.1) 4.13 (0.4) <0.001 λ1 peak height 5.18 (0.6) 6.93 (0.8) n.s. λ1 peak position 1.78 (0.2) 4.76 (0.6) <0.001 Average λ2 2.02 (0.3) 5.39 (0.6) <0.001 λ2 peak height 3.30 (0.3) 4.37 (0.5) n.s. λ2 peak position 1.50 (0.1) 5.33 (0.6) <0.001 Average λ3 4.71 (0.5) 6.80 (0.7) 0.009 λ3 peak height 5.49 (0.6) 6.89 (0.8) n.s. λ3 peak position 6.06 (0.7) 12.19 (1.1) <0.001 Note.—λ1–λ3 = eigenvalues of the diffusion tensor; n.s., not significant.
* Statistical analysis: comparisons were conducted by using a bootstrap resampling technique.
In this issue
Jump to section
Related Articles
Cited By...
- Diffusion MRI Indices and their Relation to Cognitive Impairment in Brain Aging: The updated multi-protocol approach in ADNI3
- Diffusion MRI of white matter microstructure development in childhood and adolescence: Methods, challenges and progress
- In utero diffusion tensor imaging of the fetal brain: a reproducibility study
- Multicentre imaging measurements for oncology and in the brain
- Diffusion Magnetic Resonance Histograms as a Surrogate Marker and Predictor of Disease Progression in CADASIL: A Two-Year Follow-Up Study