Table IV.
Estimation of model parameters
| Multimodal | fMRI model | Optical model | Model range | ||
|---|---|---|---|---|---|
| Dynamic evoked states | ΔCMRO2max [%] | 16.8 ± 2.2 | 16.0 ± 2.3 | 18.3 ± 2.1 | 0–100 % |
| (Dilation) ΔDiameter [%] | 5.8 ± 1.1 | 5.6 ± 1.2 | 6.5 ± 0.7 | 0–90% | |
| (Contraction) ΔDiameter [%] | 4.0 ± 2.3 | 3.7 ± 2.3 | 4.6 ± 2.1 | 0–90% | |
| Static biomechanical parameters | RA(0) | 0.73 ± 0.06 | 0.73 ± 0.04 | 0.74 ± 0.06 | 0.20–90 |
| β | 2.39 ± 0.31 | 2.57 ± 0.34 | 1.56 ± 0.12 | 1.1–4 | |
| τ [s] | 1.61 ± 0.22 | 1.64 ± 0.27 | 1.14 ± 0.13 | 0.5–4s | |
| τpial [s] | 2.23 ± 0.38 | 2.12 ± 0.68 | 2.21 ± 0.15 | 0–4s | |
| SaO2 [%] | 95.0 ± 0.2 | (95.0) | (95.0) | 90–100% | |
| ScO2 [%] | 77.6 ± 0.4 | (77.6) | (77.6) | 60–90% | |
| SvO2 [%] | 63.6 ± 0.6 | (63.6) | (63.6) | 55–89% | |
| Observation model | V0 [%] | 5.17 ± 0.45 | 5.10 ± 0.52 | N/a | 1–10% |
| ε | 3.81 ± 0.02 | 3.75 ± 0.03 | N/a | 1–5.5 | |
| [HbT]0 [μM] | 100.4 ± 7.1 | N/a | 95.2 ± 5.8 | 40–140μM | |
| ωpial | 0.56 ± 0.07 | N/a | 0.43 ± 0.07 | 0–1 | |
| ΔFlow: ΔVolume | 3.33 ± 0.12 | 3.40 ± 0.10 | 3.06 ± 0.07 | ||
| ΔFlow: ΔCMRO2 | 1.50 ± 0.28 | 1.54 ± 0.35 | 1.81 ± 0.26 | ||
This table shows the vascular model parameters estimated using combinations of the pulsed ASL and/or NIRS measurement data sets. In the model fit to the entire multimodal data set, the baseline oxygen saturation for the three vascular compartments was also estimated (SaO2‐arterial; ScO2‐capillary; SvO2‐venous). For the remaining models, these values were not fit (assumed values are given in parentheses). The 95% uncertainty bound for each parameter was estimated from Markov Chain Monte Carlo simulations using the data set (the 50% and 75% confidence intervals are also presented as box plots in Fig. 7). Model parameters are defined further in the methods section and Tables I, II, III.