Magnetohydrodynamics of blood flow

Area of Science:

• Biophysics
• Medical Imaging
• Magnetohydrodynamics

Background:

• In vivo Nuclear Magnetic Resonance (NMR) spectroscopy requires strong static magnetic fields.
• Concerns exist regarding potential biological effects of high magnetic fields on human vasculature.
• Previous studies used approximate models predicting significant vascular changes.

Purpose of the Study:

• To estimate changes in hydrostatic pressure and electrical potentials in human vasculature under high static magnetic fields (up to 10 T).
• To determine the feasibility of in vivo NMR spectroscopy at high magnetic field strengths.
• To compare exact and approximate magnetohydrodynamic solutions for fluid flow in magnetic fields.

Main Methods:

• Developed an exact analytical solution to the magnetohydrodynamic equations for a conducting fluid in a transverse magnetic field.
• Modeled fluid flow in a nonconducting, straight, circular tube representing human vasculature.
• Compared the exact solution with a previous approximate solution that neglected induced magnetic fields.

Main Results:

• A 10-T magnetic field alters vascular pressure by less than 0.2% in the modeled human vasculature.
• The exact magnetohydrodynamic solution accurately predicted experimental results for 15% NaCl flow transverse to 2.3- and 4.7-T fields.
• The approximate solution significantly overestimated flow retardation, predicting effects not observed experimentally.

Conclusions:

• High static magnetic fields (up to 10 T) are unlikely to cause significant changes in vascular pressure.
• The exact magnetohydrodynamic solution provides a more accurate prediction of fluid dynamics in magnetic fields than approximate models.
• This study supports the feasibility of using high magnetic fields for in vivo NMR spectroscopy with minimal predicted vascular impact.