Fig. 2
Phase-contrast MRI of the cerebral aqueduct (a–g) and cranio-cervical junction (h–n) in a 75 years old male individual with iNPH. Cerebral aqueduct: (a) The ROI (0.099 cm2, number of pixels 42) is shown in red and the reference ROI in blue. b CSF flow velocity is shown for the different pixels with mean flow velocity of all pixels indicated by a dark line, including noise level of pixels in reference tissue (colored lines) with mean noise level indicated by dark stippled line. The velocities from each pixel were assessed using MATLAB, and expressed as centimeters per second. Positive values refer to cranial CSF flow direction and negative values caudal CSF flow direction. The CSF flow for the different pixels is also indicated in 2D demonstrating (c) upward (retrograde) flow and (d) downward (antegrade) flow. 3D presentations of CSF flow are presented showing (e) upward flow, (f) combined, and (g) downward flow. Cranio-cervical junction: (h) The ROI (1.963 cm2, number of pixels 636) is shown in red and the reference ROI in blue. i CSF flow velocity is shown for the different pixels with mean flow velocity of all pixels indicated by a dark line, including noise level of pixels in reference tissue (colored lines) with mean noise level indicated by dark stippled line. The CSF flow for the different pixels is also indicated in 2D demonstrating (j) upward (retrograde) flow and (k) downward (antegrade) flow. 3D presentations of CSF flow are presented showing (l) upward flow, (m) combined, and (n) downward flow