Proton Magnetic Resonance Phantoms and Aging of Packed Red Blood Cell Samples

Proron magnetic resonance (pmr) phantoms of packed red blood cell (PRBC) samples were made of com starch solutions, that also contained Fe²⁺ or/and Fe³⁺ ions. Their respective spin-lattice (T₁), spin-spin (T₂) relaxation times and T₁/T₂ ratios were comparable to those of-fresh or aged-PRBC samples. The T₁ of such a pmr phantom was indicative of the concentration(s) of the paramagnetic metal ion(s) in the particular corn starch solution. The T₂ of a pmr phantom-corresponding to fresh PRBC sample-related more to that of the corn starch solution, which did not incorporate any paramagnetic metal in it. T₂ of the phantom, corresponding to aged PRBC samples, was significantly shorter. The extent of the T₂ shortening, corresponding to the concentration(s) of paramagnetic metal ions, in such corn starch solutions was distinguishable. PRBC samples were processed from freshly drawn human venous blood. While the respective changes in T₁ and T₂ of six samples were monitored for the sixty-days period, such changes for four other samples were recorded for ninety days. During the sixty-days period-in case of either investigation-the hemoglobin content became converted to methemoglobin in most of those samples.