sodium-dodecyl-sulfate and 2-phenyl-4-4-5-5-tetramethylimidazoline-1-oxyl-3-oxide

The resolution and signal to noise ratio of EPR imaging and T(1)-weighted MRI were compared using an identical phantom. Several solutions of nitroxyl contrast agents with different EPR spectral shapes were tested. The feasibility of T(1)-weighted MRI to detect nitroxyl contrast agents was described. T(1)-weighted MRI can detect nitroxyl contrast agents with a complicated EPR spectrum easier and quicker; however, T(1)-weighted MRI has less quantitative ability especially for lipophilic nitroxyl contrast agents, because T(1)-relaxivity, i.e. accessibility to water, is affected by the hydrophilic/hydrophobic micro-environment of a nitroxyl contrast agent. The less quantitative ability of T(1)-weighted MRI may not be a disadvantage of redox imaging, which obtains reduction rate of a nitroxyl contrast. Therefore, T(1)-weighted MRI has a great advantage to check the pharmacokinetics of newly modified and/or designed nitroxyl contrast agents.

Topics: Anisotropy; Buffers; Contrast Media; Cyclic N-Oxides; Electron Spin Resonance Spectroscopy; Imidazoles; Magnetic Resonance Imaging; Nitrogen Oxides; Phantoms, Imaging; Pyrrolidines; Serum Albumin, Bovine; Sodium Dodecyl Sulfate