Simple Method for Quantification of Gadolinium Magnetic Resonance Imaging Contrast Agents Using ESR Spectroscopy

Abstract

To develop an estimation method of gadolinium magnetic resonance imaging (MRI) contrast agents, the effect of concentration of Gd compounds on the ESR spectrum of nitroxyl radical was examined. A solution of either 4-oxo-2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPONE) or 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPOL) was mixed with a solution of Gd compound and the ESR spectrum was recorded. Increased concentration of gadolinium-diethylenetriamine pentaacetic acid chelate (Gd-DTPA), an MRI contrast agent, increased the peak-to-peak line widths of ESR spectra of the nitroxyl radicals, in ac

Surface modification of silica-coated gadolinium oxide nanoparticles with zinc tetracarboxyphenoxy phthalocyanine for the photodegradation of Orange G

“…Gd(III) is a paramagnetic species, however since the relaxation time of Gd(III) is extremely short, detection of Gd complexes using EPR is difficult [44]; a stronger magnet is most likely needed and the data acquired at very low temperatures to detect paramagnetic species. It may be possible that the NPs 1 and 2, have even shorter relaxation times, making detection much more difficult [44]. Though the EPR spectra did no show conclusive results, Gd is present in the NP system -as it was also accounted for with the XPS measurements.…”

Rapid In Vitro Quantification of a Sensitized Gadolinium Chelate via Photoinduced Triplet Harvesting

“…This is particularly practical for translation to clinical MRI scanners. Electron spin resonance (ESR) spectroscopy, a closely related method, has also been explored as a nondestructive method to measure clinically approved GBCAs within concentrations of 50 mM . However, all of these methods remain inadequate for the sensitivity range and relevant concentrations typically encountered in clinical settings.…”

Electron paramagnetic resonance: a powerful tool to support magnetic resonance imaging research

“…More recently, an alternative indirect method has been suggested by Takeshita et al . . They used a spin labeling approach by using nitroxide solutions.…”

“…They found a linear relationship between the concentration of Gd‐CAs and the linewidth of the nitroxide probe. Possible applications encompass the Gd quantification in plasma .…”

“…The quantification of the Gd signal intensity is a straightforward method and has the potential to be issued for many other applications. More recently, an alternative indirect method has been suggested by Takeshita et al (62). They used a spin labeling approach by using nitroxide solutions.…”