Table 4 PC-MRI-derived CSF volumetric net flow rates and directions in cranio-cervical junction

Total (CCJ; N)

32

4

18

3

4

2

1

0

Direction-independent flow

 dP (mmHg/cm)

0.040 ± 0.014

0.050 ± 0.012

0.038 ± 0.014

0.039 ± 0.012

0.042 ± 0.015

0.030 ± 0.000

0.067

–

 Total flow/cycle (ml)

1.146 ± 0.452

1.796 ± 0.516

0.916 ± 0.358^b

1.221 ± 0.201

1.239 ± 0.315

1.414 ± 0.059

1.537

–

 Absolute net flow (ml/cycle)

0.045 ± 0.047

0.074 ± 0.098

0.037 ± 0.030

0.094 ± 0.049

0.015 ± 0.014

0.029 ± 0.005

0.082

–

 Estimated absolute net flow (L/24 h)

4.726 ± 4.998

7.752 ± 10.615

4.118 ± 3.818^b

8.371 ± 4.208

1.879 ± 2.198

2.540 ± 0.204

8.381

–

Cranially-directed net CSF flow

 N

25 (78%)

4 (100%)

14 (78%)

3 (100%)

2 (50%)

1 (50%)

1 (100%)

–

 Volume (ml/cycle)

0.047 ± 0.049

0.074 ± 0.098

0.033 ± 0.024

0.094 ± 0.049

0.009 ± 0.001

0.032

0.082

–

 Estimated volume (L/24 h)

4.736 ± 5.007

7.752 ± 10.615

3.529 ± 2.557

8.371 ± 4.208

0.911 ± 0.150

2.684

8.381

–

Spinally-directed net CSF flow

 N

7 (22%)

0

4 (22%)

0

2 (50%)

1 (50%)

0

0

 Volume (ml/cycle)

0.039 ± 0.038

–

0.051 ± 0.047

–

0.021 ± 0.022

0.026

–

–

 Estimated volume (L/24 h)

4.688 ± 5.363

–

6.182 ± 6.853

–

2.848 ± 3.275

2.396

–

–

CSF_Aq-CCJ-ratio (%)

15.5 ± 14.1

2.4 ± 2.6

21.9 ± 14.1^b

7.9 ± 2.0^a

3.0 ± 3.6

24.9 ± 16.4^a

6.6

–

Other variables

 ROI (cm²)

1.671 ± 0.495

1.994 ± 0.657

1.585 ± 0.458

1.497 ± 0.466

1.766 ± 0.578

2.111 ± 0.036

1.191

–

 SNR

13.205 ± 6.263

16.745 ± 6.043

10.174 ± 4.285^a

15.863 ± 5.553

20.295 ± 5.592

8.845 ± 0.259

25.975

–

 Min velocity (cm/s)

− 1.832 ± 0.784

− 2.500 ± 0.683

− 1.615 ± 0.835

− 2.089 ± 0.419

− 1.892 ± 0.696

− 1.478 ± 0.022

− 2.778

–

 Max velocity (cm/s)

1.011 ± 0.420

1.335 ± 0.413

0.861 ± 0.334^a

1.200 ± 0.508

1.178 ± 0.555

0.766 ± 0.065

1.678

–