Sascha Khorchidi, Abstract Co-Author: Nothing to Disclose

Jakub Wiskirchen MD, Abstract Co-Author: Nothing to Disclose

Claus Detlef Claussen MD, Abstract Co-Author: Nothing to Disclose

Fritz Schick MD, Presenter: Nothing to Disclose

A complex of melanin and iron can be detected using MRI. To investigate the possibilities to enhance this effect for detection of small melanoma-metastasis, melanoma cells were incubated with contrast agent containing iron. In this in-vitro-study the detected signal was correlated with the used cell count and concentration of iron.

20.000-1.000.000 melanoma cells embedded in an agar phantom were incubated for 48 hours with 100 µg iron/ml and 1.000.000 cells for 48 hours with 20-600 µg iron/ml. MR imaging of the cell pellets was performed (3 T; T2* using TE20/TR26 and TE15/TR26; 0.4mm resolution; 20° flip angle). The diameter of the resulting signal loss was measured and correlated with the used cell count and concentration of iron.

After incubation with 100 µg iron/ml the signal loss of investigated cell pellets (20.000-1.000.000 cells) ranged from 0,67 to 4,09 mm, the resulting signal loss was increasing with increasing cell count. After incubation with various iron-conentrations (1.000.000 cells, 20-600 µg/ml) the signal loss increased with increasing amount of iron. The results both showed a cell count-/dose-dependent logarithmic relation, that did not reach saturation in the investigated range.

In the investigated range, the MRI-detected signal loss of iron-marked melanoma cells can be increased with higher cell count or increased amount of applied iron. On basis of these results in-vivo-studies on an animal-model will be performed to investigate the possibilities to enhance MRI signals of melanoma cells for detection of small melanoma-metastasis using intravenous application of iron-containing contrast agents.

Khorchidi, S, Wiskirchen, J, Claussen, C, Schick, F, To Investigate the Possibility of MR Imaging of Iron-marked Cells: Evaluation of Necessary Cell Count and Concentration of Iron.  Radiological Society of North America 2004 Scientific Assembly and Annual Meeting, November 28 - December 3, 2004 ,Chicago IL. http://archive.rsna.org/2004/4416645.html