In-vitro measurement of iron concentration in human hepatic tissue by magnetic induction methods

This article studies the feasibility of a magnetic induction (MI) based system to measure the concentration of paramagnetic material in biological tissues. Our final objective is the measurement of hepatic iron overload with a non-invasive method. We have used an analytical expression, for a disc of conducting paramagnetic or diagmagnetic material, to estimate the response of the system. Experimental data were acquired with a custom measurement system using an excitation coil and a planar gradiometer as receiver. The output of the system for different concentration of FeCl₃ solutions has been used to calibrate the system. Ten in-vitro measurements of liver samples, with a volume around 50 cm³, have been made. Measurements were compared against a biochemical iron estimation procedure and histological studies with hematoxilin-eosin and Perls Prussian blue staining. A significant agreement is observed (R=0.92, P<0.001) between biochemical and MI results. The systems and procedures used have to be adapted now for in-vivo non-invasive measurements.