NEW DEVELOPMENTS AND APPLICATIONS IN QUANTITATIVE ELECTRON SPECTROSCOPIC IMAGING OF IRON IN HUMAN LIVER BIOPSIES

Reliable iron concentration data can be obtained by quantitative analy ses of image sequences, acquired by electron spectroscopic imaging. A number of requirements are formulated for the successful application o f this recently developed irt situ quantitative type of analysis. A de monstration of the procedures is given. By application of the techniqu e it is established that there are no significant differences in the a verage iron loading of structures analysed in liver parenchymal cells of a patient with an iron storage disease, before and after phlebotomy . This supports the hypothesis that the process of iron unloading is a n organelle specific process. Measurement of the binary morphology, re presented by the area and contour ratio of the iron containing objects revealed no information about differences between the objects. This f inding contradicts the visual suggestion that ferritin clusters are mo re irregularly shaped than the other iron objects. Also, no difference s could be found in this sense between the situations before and after phlebotomy. With respect to the density appearance, objects that have an inhomogeneous iron loading averagely contain more iron. This obser vation does correspond well with the visual impression of the increasi ngly irregular appearance of more well-loaded structures. (C) 1997 Els evier Science Ltd. All rights reserved.