Table 3.
Overview of ASL-based BBB imaging in subjects with the AD continuum.
| Study | Subjects: Sample Size/Age/Diagnosis | Image acquisition parameters | Water exchange model | kw (min−1) | Main findings |
|---|---|---|---|---|---|
| Shao et al. (2019) | 19/68.8 ± 7.6/Cognitively normal and MCI | Siemens, 3 T, DP-pCASL with 3D GRASE, axial, voxel size = 3.5 × 3.5 × 8 mm3, 6 min | Regularized SPA | 98.3 ± 20.8 (Frontal lobe) | BBB water exchange rate is associated with vascular risk factors and cognitive scores |
| 97.8 ± 17.3 (Temporal lobe) | |||||
| 100.6 ± 22.2 (Parietal lobe) | |||||
| Shao et al. (2020) | 16/62–86/Cognitively normal and MCI | Siemens, 3 T, DP-pCASL with 3D GRASE, axial, voxel size = 3.5 × 3.5 × 8 mm3, 5.53 min | Regularized SPA | 122.3 ± 16.5 (Whole brain) | Only three brain regions have correlations between BBB water exchange kw and BBB permeability Ktrans |
| 122.6 ± 15.6 (Gray matter) | |||||
| 121.9 ± 17.2 (White matter) | |||||
| Joseph and Novel (2020) | 3/65–85/mild AD | Siemens, 3 T, TGSE PASL, axial, voxel size = 3.9 × 3.9 × 4 mm3, 20 min | NA | NA | Reduced paravascular clearance in mild AD |
| Gold et al. (2021) | 39/72.7/preclinical AD | Siemens, 3 T, DP-pCASL with 3D GRASE, axial, voxel size = 3.5 × 3.5 × 8 mm3, 5.53 min | Regularized SPA | 104.4 ± 22.2 (Frontal lobe) | Low BBB water exchange rate is associated with low CSF Aβ42 concentration |
| 94.8 ± 26.1 (Temporal lobe) | |||||
| 83.2 ± 28.3 (Parietal lobe) | |||||
| Ford et al. (2022) | 30/25–65+/Cognitively normal and MCI | GE, 3 T, DP-pCASL with QPM, axial, voxel size = 1.9 × 1.9 × 4 mm3, 27 min | Regularized SPA | 81.5 ± 15.4 (GM) | BBB water exchange rate is inversely correlated with age |
| 75.2 ± 13.9 (WM) | |||||
| Uchida et al. (2022a) | 66/72.2 ± 5.8/early AD | Philips, 3 T, DP-pCASL with 3D GRASE, axial, voxel size = 3.5 × 3.5 × 7 mm3, 14 min | Regularized SPA | 95.1 ± 7.32 (Frontal lobe) | BBB water exchange rate is decreased in APOE4 carriers, resulting Aβ accumulations |
| 91.3 ± 7.05 (Temporal lobe) | |||||
| 94.5 ± 7.19 (Parietal lobe) |
CSF, cerebrospinal fluid; DP-pCASL, diffusion-prepared pseudo-continuous arterial spin labeling; GRASE, gradient and spin-echo; PASL, pulsed arterial spin labeling; QPM, quantitative permeability mapping; SPA, single-pass approximation; TGSE, turbo gradient spin echo.