Effect of diffusion-sensitizing gradient timings on the exponential, biexponential and diffusional kurtosis model parameters: in-vivo measurements in the rat thalamus
- 144 Downloads
To investigate whether spacing (Δ) and duration (δ) of the diffusion-sensitizing gradient pulses differentially affect exponential (D′), biexponential (D slow, D fast and f slow) and diffusional kurtosis (D and K) model parameters.
Measurements were performed in the rat thalamus for b = 200–3,200 s mm−2, sweeping Δ between 20 and 100 ms at δ = 15 ms, and δ between 15 and 50 ms at Δ = 60 ms. Linear regressions were performed for each model parameter vs. Δ or δ.
Increasing Δ from 20 to 100 ms increases D′ (from 0.64 to 0.70 × 10−3 mm2s−1) and D slow (from 0.26 to 0.33 × 10−3 mm2s−1), reduces K (from 0.57 to 0.53), and has no effects on D fast, f slow or D. Increasing δ from 15 to 50 ms increases D (from 0.80 to 0.88 × 10−3 mm2s−1), and has no effects on the other parameters.
The parameters of the biexponential and diffusional kurtosis models are more sensitive than the exponential model to Δ and δ; however, observed effects are too small to account for the discrepancies found in literature.
KeywordsDiffusion Time Exponential model Biexponential model Diffusional kurtosis model
Unable to display preview. Download preview PDF.
- 4.Schwarcz A, Bogner P, Meric P, Correze J, Berente Z, Pal J, Gallyas F, Doczi T, Gillet B, Beloeil J (2004) The existence of biexponential signal decay in magnetic resonance diffusion-weighted imaging appears to be independent of compartmentalization. Magn Reson Med 51: 278–285CrossRefPubMedGoogle Scholar