W Coenen1, C Gutiérrez-Montes2, S Sincomb3, E Criado-Hidalgo3, K Wei4, K King4, V Haughton5, C Martínez-Bazán2, A L Sánchez3, J C Lasheras3,6. 1. From the Departments of Mechanical and Aerospace Engineering (W.C., S.S., E.C.-H., A.L.S., J.C.L.) wicoenen@ucsd.edu. 2. Department of Mechanical and Mining Engineering (C.G.-M., C.M.-B.), University of Jaén, Jaén, Andalucía, Spain. 3. From the Departments of Mechanical and Aerospace Engineering (W.C., S.S., E.C.-H., A.L.S., J.C.L.). 4. MRI Center (K.W., K.K.), Huntington Medical Research Institutes, Pasadena, California. 5. Department of Radiology (V.H.), School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin. 6. Bioengineering (J.C.L.), University of California, San Diego, San Diego, California.
Abstract
BACKGROUND AND PURPOSE: Recent flow dynamics studies have shown that the eccentricity of the spinal cord affects the magnitude and characteristics of the slow bulk motion of CSF in the spinal subarachnoid space, which is an important variable in solute transport along the spinal canal. The goal of this study was to investigate how anatomic differences among subjects affect this bulk flow. MATERIALS AND METHODS: T2-weighted spinal images were obtained in 4 subjects and repeated in 1 subject after repositioning. CSF velocity was calculated from phase-contrast MR images for 7 equally spaced levels along the length of the spine. This information was input into a 2-time-scale asymptotic analysis of the Navier-Stokes and concentration equations to calculate the short- and long-term CSF flow in the spinal subarachnoid space. Bulk flow streamlines were shown for each subject and position and inspected for differences in patterns. RESULTS: The 4 subjects had variable degrees of lordosis and kyphosis. Repositioning in 1 subject changed the degree of cervical lordosis and thoracic kyphosis. The streamlines of bulk flow show the existence of distinct regions where the fluid particles flow in circular patterns. The location and interconnectivity of these recirculating regions varied among individuals and different positions. CONCLUSIONS: Lordosis, kyphosis, and spinal cord eccentricity in the healthy human spine result in subject-specific patterns of bulk flow recirculating regions. The extent of the interconnectivity of the streamlines among these recirculating regions is fundamental in determining the long-term transport of solute particles along the spinal canal.
BACKGROUND AND PURPOSE: Recent flow dynamics studies have shown that the eccentricity of the spinal cord affects the magnitude and characteristics of the slow bulk motion of CSF in the spinal subarachnoid space, which is an important variable in solute transport along the spinal canal. The goal of this study was to investigate how anatomic differences among subjects affect this bulk flow. MATERIALS AND METHODS: T2-weighted spinal images were obtained in 4 subjects and repeated in 1 subject after repositioning. CSF velocity was calculated from phase-contrast MR images for 7 equally spaced levels along the length of the spine. This information was input into a 2-time-scale asymptotic analysis of the Navier-Stokes and concentration equations to calculate the short- and long-term CSF flow in the spinal subarachnoid space. Bulk flow streamlines were shown for each subject and position and inspected for differences in patterns. RESULTS: The 4 subjects had variable degrees of lordosis and kyphosis. Repositioning in 1 subject changed the degree of cervical lordosis and thoracic kyphosis. The streamlines of bulk flow show the existence of distinct regions where the fluid particles flow in circular patterns. The location and interconnectivity of these recirculating regions varied among individuals and different positions. CONCLUSIONS:Lordosis, kyphosis, and spinal cord eccentricity in the healthy human spine result in subject-specific patterns of bulk flow recirculating regions. The extent of the interconnectivity of the streamlines among these recirculating regions is fundamental in determining the long-term transport of solute particles along the spinal canal.
Authors: Christof Karmonik; Matthias Müller-Eschner; Sasan Partovi; Philipp Geisbüsch; Maria-Katharina Ganten; Jean Bismuth; Mark G Davies; Dittmar Böckler; Matthias Loebe; Alan B Lumsden; Hendrik von Tengg-Kobligk Journal: Vasc Endovascular Surg Date: 2013-09-17 Impact factor: 1.089
Authors: Jacob Y Hesterman; Susan D Kost; Robert W Holt; Howard Dobson; Ajay Verma; P David Mozley Journal: J Nucl Med Date: 2017-03-23 Impact factor: 10.057
Authors: C Gutiérrez-Montes; W Coenen; M Vidorreta; S Sincomb; C Martínez-Bazán; A L Sánchez; V Haughton Journal: AJNR Am J Neuroradiol Date: 2022-08-18 Impact factor: 4.966
Authors: Jose De Andres; Salim Hayek; Christophe Perruchoud; Melinda M Lawrence; Miguel Angel Reina; Carmen De Andres-Serrano; Ruben Rubio-Haro; Mathew Hunt; Tony L Yaksh Journal: Front Pain Res (Lausanne) Date: 2022-06-16