MAPPING OF THE SPATIAL VARIATION IN ALGINATE CONCENTRATION IN CALCIUMALGINATE GELS BY MAGNETIC-RESONANCE-IMAGING (MRI)

A series of homogeneous calcium alginate gels, prepared in the presenc e of anti-gelling ions, were used to produce a calibration curve relat ing the spin-spin relaxation time (T2) of the water protons in the gel to the concentration of alginate. This was then used to calculate the spatial variation of alginate concentration in an inhomogeneous calci um alginate gel from a T2 map computed from a series of one-dimensiona l MR-projection images. The concentration gradient for alginate derive d thereby compared favourably with that subsequently obtained by physi cal sectioning of the gel.