Table 2.

Physiological and anatomical comparisons between cases and controls

	SIH		REF	P-value
CSF clearance
T1/2, abs (h)	1.05 ± 0.45		4.53 ± 2.92	0.04
Tmax (h)	2.97 ± 1.36		8.02 ± 4.50	0.05
Cmax (µM)	7.50 ± 3.31		3.36 ± 1.64	0.01
Tlag (h)	0.34 ± 0.39		0.46 ± 0.48	0.67
AUC0−∞ (µM h)	74.71 ± 27.65		68.64 ± 7.23	0.53
Volume measures
Cerebral cortex (mL)	501.96 ± 42.20		512.33 ± 54.20	0.70
Frontal cortex (mL)	196.81 ± 20.66		203.68 ± 23.17	0.53
Temporal cortex (mL)	111.03 ± 12.26		110.39 ± 12.84	0.92
Parietal cortex (mL)	137.39 ± 7.31		140.77 ± 13.34	0.54
Occipital cortex (mL)	56.71 ± 6.35		57.50 ± 7.70	0.82
Cerebellar cortex (mL)	107.94 ± 9.65		105.04 ± 10.89	0.57
4th ventricle (mL)	1.28 ± 0.34		1.58 ± 0.29	0.067
3rd ventricle (mL)	0.93 ± 0.60		0.94 ± 0.32	0.93
Lateral ventricles (mL)	18.04 ± 12.05		19.60 ± 12.04	0.79
Choroid plexus (mL)	1.29 ± 0.35		1.34 ± 0.33	0.74
First time CSF tracer appearance
Cisterna magna (min)	14.50 ± 8.82		10.78 ± 5.22	0.30
PVSAS of anterior cerebral artery (A2; min)	27.00 ± 9.85		39.00 ± 20.58	0.27
PVSAS of anterior cerebral artery (distal)	67.60 ± 45.63		72.40 ± 38.85	0.86
PVSAS of middle cerebral artery (M2; min)	36.20 ± 11.37		33.80 ± 20.00	0.82
PVSAS of middle cerebral artery (M3; min)	80.20 ± 50.45		65.60 ± 43.98	0.64
CSF flow measures
Net antegrade flow Sylvian aqueduct (mL/min)	0.75 ± 1.00		0.26 ± 0.22	0.25
Net upward flow cranio-cervical junction (mL/min)	0.98 ± 0.96		-

PVSAS: Perivascular subarachnoid space. CSF clearance variables: T_{1/2, abs}: Time (minutes) to 50% of tracer dose absorbed to blood (absorption half-life), indicative of CSF tracer clearance to blood. T_max: Time (minutes) to maximum concentration. C_max: Dose-normalized maximum concentration. T_lag: lag-time (minutes) of absorption. AUC_0−∞: Dose-normalized area under curve from zero to infinity. Min: Minutes. Continuous variables were compared with independent samples t-test