Many flow visualization techniques, especially integration-based methods, are problematic when the measured data exhibit noise and discretization issues. Particularly, this is the case for flow-sensitive phase-contrast magnetic resonance imaging (PC-MRI) data sets which not only record anatomic information, but also time-varying flow information. We propose a novel approach for the visualization of such data sets using integration-based methods. Our ideas are based upon finite-time Lyapunov exponents (FTLE) and enable identification of vessel boundaries in the data as high regions of separation. This allows us to correctly restrict integration-based visualization to blood vessels. We validate our technique by comparing our approach to existing anatomy-based methods as well as addressing the benefits and limitations of using FTLE to restrict flow. We also discuss the importance of parameters, i.e., advection length and data resolution, in establishing a well-defined vessel boundary. We extract appropriate flow lines and surfaces that enable the visualization of blood flow within the vessels. We further enhance the visualization by analyzing flow behavior in the seeded region and generating simplified depictions.
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http://dx.doi.org/10.1109/TVCG.2011.80 | DOI Listing |
Neuroinformatics
January 2025
Translational Neuroimaging Group, Center for Image Sciences, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands.
Blood flow velocity in the cerebral perforating arteries can be quantified in a two-dimensional plane with phase contrast magnetic imaging (2D PC-MRI). The velocity pulsatility index (PI) can inform on the stiffness of these perforating arteries, which is related to several cerebrovascular diseases. Currently, there is no open-source analysis tool for 2D PC-MRI data from these small vessels, impeding the usage of these measurements.
View Article and Find Full Text PDFMagn Reson Imaging
December 2024
Department of Radiology, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China. Electronic address:
Purpose: To evaluate cerebrospinal fluid (CSF) flow dynamics and volume changes of pulsatile tinnitus (PT) patients induced by sigmoid sinus wall dehiscence (SSWD) with intracranial hypertension.
Methods: Thirty-five SSWD-PT patients coexisted with intracranial hypertension and 35, age-, gender-, and handedness-matched healthy volunteers were prospectively enrolled and performed MRI. Clinical data were collected.
Radiol Cardiothorac Imaging
December 2024
From the Departments of Radiology (E.K.E., T.F., M.L.M., L.P.B., A.J.B.), Pediatrics-Cardiology (R.M.F.), and Bioengineering (A.J.B.), University of Colorado Anschutz Medical Campus, 13123 E 16th Ave B125, Aurora, CO 80045; and Department of Radiology, Children's Hospital Colorado, Aurora, Colo (S.A.S., A.J.B.).
Acta Neurochir (Wien)
November 2024
Department of Neurosurgery and Neurooncology, Military University Hospital and Charles University, U Vojenské Nemocnice 1200/1, 162 00, Prague 6, Czech Republic.
Unlabelled: PURPOSE : Phase contrast magnetic resonance imaging (PC-MRI) represents an opportunity to non-invasively investigate cerebral spinal fluid (CSF) flow in patients with idiopathic normal pressure hydrocephalus (iNPH). Studies in recent years have explored the diagnostic and prognostic value of PC-MRI derived parameters. This review aims to identify all PC-MRI studies of iNPH published since 2010, synthesise a review based on collated results, and analyse specific flow parameters identified in the selected studies.
View Article and Find Full Text PDFFluids Barriers CNS
October 2024
Medical Image Processing Department, CHU Amiens-Picardie University Hospital, Amiens, France.
Background: Following the Monro-Kellie doctrine, the Cerebral Blood Volume Changes (CB_VC) should be mirrored by the Cerebrospinal Fluid Volume Changes (CSF_VC) at the spinal canal. Cervical level is often chosen to estimate CB_VC during the cardiac cycle. However, due to the heterogeneity in the anatomy of extracranial internal jugular veins and their high compliance, we hypothesize that the intracranial level could be a better choice to investigate blood and cerebrospinal fluid (CSF) interactions.
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