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FIG 2. Aqueductal stenosis.
A. Sagittal midline T1-weighted image (SE 450/15/2) reveals moderate ventricular dilatation with diffuse narrowing of aqueduct.
B. Proton-density-weighted axial image (SE 2200/20/1) at level of third ventricle shows abnormal flow-void at anterior recesses of third ventricle (arrow).
C. Sagittal midline phase-contrast MR imaging (2D-FISP 70/13/15°). A midsystolic image (left) shows caudal flow (black signal) at level of floor of third ventricle and prepontine cistern, while in middiastolic image (right) flow is reversed (white signal), indicating bidirectional flow through floor of third ventricle.
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