Vascular Compliance in Normal Pressure Hydrocephalus
Grant A. Batemana
a From the Department of Medical Imaging, Locked Bag 1, Newcastle Region Mail Center, 2310 Australia. Address reprint requests to Dr. Grant Bateman.
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FIG 1. A, Scout image shows site of flow quantification acquisition.
B, Axial scout image in the same plane as the flow study shows the carotid artery (long arrow), the straight sinus (short thin arrow), and the SSS (short thick arrow).
C, Axial phase image in the same plane as B.
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fig 2. Arterial and venous flow in the SSS territory in a healthy patient.
fig 3. Arterial and venous flow in the SSS territory in a patient with atrophy
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FIG 4. A, Blood flow in SSS territory before tap test shows very similar arterial and venous flows with minimal delay.
B, Blood flow in SSS territory immediately after removal of 30 mL of CSF. Note the arterial curve now peaks earlier, is higher, and is thinner. The venous curve peaks later, is lower, and is wider.
C, Net blood flow before and after tap test. The divergence of the curves after intervention has led to a larger overall pulsation in systole (positive half of curve).
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FIG 5. A, The pathophysiology of atrophy. Straight black arrows indicate the magnitude of the pulsations; white arrow near the SSS, volume of CSF leaving the system through the incisura of the tentorium; curved black arrows between the capillary beds, bulk fluid flow; SSS, superior sagittal sinus; ST, straight sinus; V, ventricle.
B, The pathophysiology of NPH. Straight black arrows denote vessel pulsation magnitudes; curved black arrows, interstitial fluid bulk flow; white arrow, CSF flow; SSS, superior sagittal sinus; ST, straight sinus; V, ventricle.
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AJNR - American Journal of Neuroradiology