Proton Spin Relaxation in Aqueous Solutions of Paramagnetic Ions. II. Cr+++, Mn++, Ni++, Cu++, and Gd+++

Abstract

Nuclear magnetic relaxation times for protons in dilute aqueous solutions of chromic, manganous nickel, cupric, and gadolinium ions were measured in the frequency range 1.9 to 60 Mc/sec. Results we:e interpreted in terms of Solomon's formulation of electron-nuclear dipole-dipole interaction and Bloembergen's expression for scalar coupling of electron and nuclear spins. In large magnetic fields relaxation times were found to be shorter than those expected on the basis of low field values, suggesting that the effective ion magnetic moments, electron spin relaxation times, and/or electron-nuclear spin exchange constants are field-dependent.

QA: Quality Assurance, Accuracy, Precision and Phantoms

“…Agarose is relatively expensive if large volumes are to be made up, cooking it is a relatively complex process, and obtaining a uniform gel on cooling also requires skill. Commercially available doped gels with a wide Morgan and Nolle (1959) range of T 1 and T 2 values are obtainable (see Section 3.1); however for many applications single liquids or aqueous solutions will suffice.…”

Extensive NMRD studies of Ni(II) salt solutions in water and water–glycerol mixtures

“…In this communication, we return to a very simple case of acidified aqueous solutions of the nickel ions, Ni(II). The system has been studied many times, beginning with the classical study by Morgan and Nolle [6], who found no field dependence for the proton spin-lattice relaxation time in the field range 0.05-1.4 T. Bloembergen and Morgan [7] explained this observation in terms of rapid electron spin relaxation, caused by fluctuations of the zero-field splitting, ZFS, originating from collisional distortions of the hydration sphere of the ion. In late eighties, we reported an investigation of low-pH aqueous solution of Ni(II) at a series of magnetic field up to 11.7 T [8] and interpreted the experimental data using a theoretical model of Westlund et al [9].…”

Simplified treatment planning for interstitial laser thermotherapy by disregarding light transport: A numerical study

“…The anisotropy factor (g) was previously measured to be approximately 0.9 at low ink concentrations [33]. To improve the signal-tonoise ratio, the T1 relaxation time of the gel was reduced by doping the solution with 5.3 mM Ni 2+ [35]. Transmission through the laser fiber, with a 20-mm-long diffusing section and an outer diameter of 1.45 mm (Lightstic™, Rare Earth Medical, West Yarmouth, MA), was measured by using an integrating sphere power meter (Laser Therapeutics Inc., Buellton, CA).…”