Correction on FID NMR signal induced by Mesoscopic Magnetic Field Inhomogeneities at High Volume Fraction
He X, Sukstanskii A
Washington University School of Medicine
At high volume fraction, the FID NMR signal at static dephasing regime deviates from the signal behavior predicated by Yablonskiy and Haacke. When the possibility of overlapping between magnetized objects can not be ignored, the distribution function is not uniform and independent anymore. Using an approach analogy to mean field approximation, the hard sphere model predicates a slightly higher probability for the object residing close to the medium position. The correction of FID NMR singal at the short time and long time scale indicates that underestimation of volume fraction can occur if the correction term is ignored.