Patent ID: 8855740

Claim:
A method of analyzing a tumor in a subject, the method comprising: sequentially introducing a plurality of solutions, each containing a predetermined range of sizes of magnetic nanoparticles (MNPs), respectively, into the tumor; capturing an MRI image of the tumor after the introduction of each solution; comparing the plurality of captured MRI images to a plurality of stored images, each stored image having corresponding MNP size and size distribution information as determined by a computer-implemented method of determining a size and size distribution of superparamagnetic nanoparticle cores in a sample comprising: performing a magnetic measurement analysis of the sample and generating magnetization data therefrom; determining an asymptotic portion of high field data from the magnetization data for each of four branches (A,B,C,D) as M H vs. 1/H where M H is the measured magnetization in a magnetic field of intensity H approaching its saturation value; performing a linear regression analysis of the data in each branch and generating a first correlation curve of the form M H =α/H+β; calculating both a number average particle volume, {tilde over (V)} n , and a saturation magnetization, M sat , of the sample, as a function of the first correlation curve; combining low field, linear data of M H for branches A and C, and branches B and D, and obtaining two plots of M H vs. H for values of H within a range from −50 Oe to +50 Oe; performing a linear regression analysis of the data in each branch combination and generating a second correlation curve of the form M H =γH+δ; calculating a volume average particle volume {tilde over (V)} v as a function of the saturation magnetization value M sat obtained from the high field measurements, and using the value of the slope γ for the ratio of M H /H; calculating a volume average spherical equivalent magnetic particle diameter {hacek over (D)} v and a number average spherical equivalent magnetic particle diameter {hacek over (D)} n as a function of {tilde over (V)} v and {tilde over (V)} n ; and calculating a dispersity value, d , of the sample, as a function of the diameter values {hacek over (D)} v and {hacek over (D)} n ; and analyzing the tumor as a function of the comparison of the plurality of captured MRI images to the plurality of stored images.