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Biologische Systeme und Medizin Poster: Mi., 14:00–16:30 M-P189
Two-dimensional elemental mapping of liver tissue sections by micro-SRXRF
Gerald Falkenberg 1 , Romana Höftberger 2 , Friedrich Wrba 3 , Wolf
Osterode 4
1 Deutsches Elektronensynchrotron DESY – 2 Medizin Universität Wien, Klinisches Institut
für Neurologie – 3 Medizin Universität Wien, Klinisches Institut für Pathologie –
4 Medizin Universität Wien, Univ. Klinik für Inner Medizin IV
The comparison of X-ray fluorescence elemental maps with biological structures in
histological slices requires often the scanning of large areas in the millimetre range,
but with microscopic resolution. To test whether large two-dimensional scans can
be performed in an appropriate time with sufficient statistics we investigated normal
liver tissue and liver tissue from patients with genetically disturbed iron metabolism
(haemochromatosis, HC) in a continuous scanning mode by microscopic Synchrotron
radiation induced X-ray fluorescence analysis (micro-SRXRF). Methods: micro-SRXRF
measurements were performed at beamline L of DORIS III storage ring at HASY-
LAB/DESY in Hamburg. Slices of 10 µm thickness - imbedded in paraffin - were
fixed on trace element free Ultralene foil for investigation. The white beam of the
bending magnet was monochromatized by a double multilayer monochromator (NiC).
The energy of the incoming beam was set to 17.5 keV for all measurements, and the
monochromatic X-ray beam was focused by a polycapillary half-lens to a cross section
of 15 µm providing a flux of 10 11 photons/s. A Silicon multi-cathode X-ray Spectrometer
VORTEX-EX (Radiant Detector Technologies) was employed in combination with
a CANBERRA 2060 digital pulse processor. The system provided an excellent energy
resolution of 160 eV (5.8 keV) for all count rates up to 80 000 cts/s. Several samples
were scanned with 15 µm step size and 1 s sample time per pixel over different area
sizes ranging up to 3 x 3 mm 2 (40000 points, 11 h total scanning time). Element concentrations
are calculated with a Fundamental Parameter code from normalized line
intensities by comparison to an external reference sample (sputtered Ge film). Results:
In normal liver tissue, after fixation and imbedding in paraffin, mean Fe, Cu and Zn
concentrations were 152 ± 54, 20.1 ± 4.3 and 88.9 ± 19.5 µg/g sample weight, respectively.
No substantial, characteristic differences in their distribution were found
in the two-dimensional scans. In slices from patients with HC mean Fe, Cu and Zn
concentrations were 1102 ± 53.9, 35.9 ± 14.6 and 27.2 ± 6.7 µg/g sample weight,
respectively. Additionally, a significant decrease in phosphorus and sulphur concentrations
existed. The increased Cu concentration around cirrhotic regenerations nodules
is mostly associated with a lymphocytic infiltration in this region. Analyzing Fe in
different sample regions reveals negative dependencies between Fe and Cu, Cu and Zn,
but a positive dependence between Fe and Zn. Conclusion: In the continuous scanning
mode elemental distribution in a near histological resolution (20 x light microscope)
can be achieved in due time providing additional metabolic features.