Magnetic Orientational Properties of Monosodium Urate Crystals

• Published in: IEEE transactions on magnetics Vol. 53; no. 11; pp. 1 - 4
• Main Authors: Takeuchi, Y., Sekiya, M., Hamasaki, A., Iwasaka, M., Matsuda, M.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.11.2017; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Crystal structure; Crystals; Fluids; Gout; Inclination; magnetic field; Magnetic fields; magnetic orientation; Magnetic properties; Magnetic resonance imaging; Magnetic susceptibility; Magnetism; Molecular structure; monosodium urate (MSU) crystal; Perpendicular magnetic anisotropy; Rheumatism; Sodium hydroxide; Uric acid
• ISSN: 0018-9464; 1941-0069
• DOI: 10.1109/TMAG.2017.2726525

Monosodium urate (MSU) crystals are the cause of gout and are formed from uric acid and sodium. Because they can be rotated by the torque induced by an applied magnetic field, we have characterized their detailed magnetic orientational properties to improve the detection sensitivity from outside the body using the magnetic orientation. The MSU crystals were precipitated by dissolving uric acid powder in aqueous sodium hydroxide. In serum, the MSU crystals were small and uniformly sized, similar to those obtained from gout patients. The MSU crystals were not completely oriented perpendicular to the magnetic-field direction, but rather the c-axis of the crystal was inclined with respect to the field direction. Specifically, they were inclined at a mean of 69.3° under a magnetic field of 500 mT. The MSU crystals were not perfectly oriented in magnetic fields <;200 mT. The inclination results from the molecular structure of the MSU crystal.