Table 2:

Peak systolic and diastolic CSF velocities in 5 human volunteers at the level of the foramen magnum defined in sagittal images by the tip of the clivus anteriorly and the occipital bone posteriorly

	RPC	CPC	Absolute Difference
Systolic peak velocity (cm/s)
Volunteer 1	2.2	2.4	0.2
Volunteer 2	4.3	4.0	0.3
Volunteer 3	3.7	3.6	0.1
Volunteer 4	2.1	2.2	0.1
Volunteer 5	2.0	2.2	0.2
Averagea	2.9 ± 1.1	2.9 ± 0.9	0.2 ± 0.1
Diastolic peak velocity (cm/s)
Volunteer 1	1.0	1.1	0.1
Volunteer 2	0.9	1.0	0.1
Volunteer 3	1.6	1.4	0.2
Volunteer 4	0.4	0.8	0.4
Volunteer 5	0.8	0.8	0.0
Averagea	0.9 ± 0.4	1.0 ± 0.3	0.2 ± 0.2

^a Mean values ± SDs.