Date of download: 6/9/2016 Copyright © ASME. All rights reserved. From: Cerebral Blood Flow in a Healthy Circle of Willis and Two Intracranial Aneurysms: Computational Fluid Dynamics Versus Four-Dimensional Phase-Contrast Magnetic Resonance Imaging J Biomech Eng. 2014;136(4): doi: / Surface models of the investigated cases: complete Circle of Willis of a healthy volunteer (case CoW, top), anterior communicating artery aneurysm (case AcomA, bottom left), and middle cerebral artery aneurysm (case MCA, bottom right). The surface of the whole circulatory system is based on the flow measurement, whereas the aneurysms are reconstructed from the precise TOF sequences. The red circles indicate their location within the Circle of Willis. Figure Legend:

Date of download: 6/9/2016 Copyright © ASME. All rights reserved. From: Cerebral Blood Flow in a Healthy Circle of Willis and Two Intracranial Aneurysms: Computational Fluid Dynamics Versus Four-Dimensional Phase-Contrast Magnetic Resonance Imaging J Biomech Eng. 2014;136(4): doi: / Representation of the methods used for qualitative and quantitative analysis, respectively: orthogonal cut planes (red and green) and arbitrary point cloud (blue) Figure Legend:

Date of download: 6/9/2016 Copyright © ASME. All rights reserved. From: Cerebral Blood Flow in a Healthy Circle of Willis and Two Intracranial Aneurysms: Computational Fluid Dynamics Versus Four-Dimensional Phase-Contrast Magnetic Resonance Imaging J Biomech Eng. 2014;136(4): doi: / Qualitative comparison of peak-systolic velocity profiles at characteristic locations within the circulatory system. Numerical results (CFD) are represented as transparent shapes, whereas the flow measurements (MRI) are visualized as opaque profiles. At each location the cross-sectional velocity magnitudes are displayed (upper—MRI; lower—CFD). The internal carotid artery profiles correspond to the upper velocity legend and the lower ones are scaled different to preserve a comparable profile height. Figure Legend:

Date of download: 6/9/2016 Copyright © ASME. All rights reserved. From: Cerebral Blood Flow in a Healthy Circle of Willis and Two Intracranial Aneurysms: Computational Fluid Dynamics Versus Four-Dimensional Phase-Contrast Magnetic Resonance Imaging J Biomech Eng. 2014;136(4): doi: / Comparison of peak-systolic velocity magnitude fields at selected orthogonal cut planes. Top: Anterior communicating artery aneurysm of case AcomA (t A = s). Bottom: Middle cerebral artery aneurysm of case MCA (t M = s). The first and third column of each case represents the CFD results, whereas the second and fourth column is associated with the MRI measurements. Peak systole was assumed for the highest flow rates through the inlet cross section during one cardiac cycle. Figure Legend:

Date of download: 6/9/2016 Copyright © ASME. All rights reserved. From: Cerebral Blood Flow in a Healthy Circle of Willis and Two Intracranial Aneurysms: Computational Fluid Dynamics Versus Four-Dimensional Phase-Contrast Magnetic Resonance Imaging J Biomech Eng. 2014;136(4): doi: / Quantitative analyses of the three-dimensional measured and simulated velocity fields. Left to right column: Healthy Circle of Willis at systole and diastole, respectively; anterior communicating artery aneurysm (AcomA) at systole; middle cerebral artery aneurysm (MCA) at systole. Top to bottom row: Direct comparison of the experimental and numerical velocity magnitudes with a line indicating a perfect match; angular similarity index (ASI); magnitude similarity index (MSI), both with a maximum value of 1. Figure Legend: