Eine Präparationstechnik zur quantitativen Untersuchung SPIO-haltiger Lösungen und SPIO-markierter Zellen in der MRT / A preparation technique for quantitative investigation of SPIO-containing solutions and SPIO-labelled cells by MRI

Pintaske, Jörg; Helms, Gunther; Bantleon, Rüdiger; Kehlbach, Rainer; Wiskirchen, Jakub; Claussen, Claus D.; Schick, Fritz

doi:10.1515/bmt.2005.024

Cited by 8 publications

(8 citation statements)

References 20 publications

(25 reference statements)

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“…Although the transverse relaxation rates correlate with the amount of iron, we observed persistent MR signal alterations, despite a reduction in iron content. This result is consistent with the findings of Pintaske et al, 21 indicating that the diameters of the MRI signal extinction correspond to a logarithmic function that is dependent on the iron concentration and flatten out considerably with high iron concentrations. Furthermore, Pintaske et al 21 and Tanimoto et al 31 provided evidence that the extent of the signal extinction was dependent upon the geometric distribution of the iron particles.…”

Section: Discussionsupporting

confidence: 93%

“…21 Briefly, a 1% agar solution (dissolved in PBS) was boiled and slowly cooled in a 37°C water bath to minimize air bubbles that would produce artifacts during MRI. Before congealing, the agar was embedded in specialized plastic boxes.…”

Section: Methodsmentioning

confidence: 99%

“…The resolution can be changed at both field strengths. Pintaske et al 24 described that the use of high resolution improves the accuracy of geometric localization but decreases the MRI sensitivity. The resolution (0.25 to 0.50 mm) and cell number chosen for each experiment at the respective field strengths are specified in the figure legends.…”

Section: Methodsmentioning

confidence: 99%

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Labeling Human Melanoma Cells With SPIO

et al. 2016

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Objectives:To use the superparamagnetic iron oxide (SPIO) contrast agent Resovist (±transfection agent) to label human melanoma cells and determine its effects on cellular viability, microstructure, iron quantity, and magnetic resonance imaging (MRI) detectability.Materials and Methods:Human SK-Mel28 melanoma cells were incubated with Resovist (±liposomal transfection agent DOSPER). The cellular iron content was measured, and labeled cells were examined at 1.5 T and 3.0 T. The intracellular and extracellular distributions of the contrast agent were assessed by light and electron microscopy.Results:The incubation of melanoma cells with SPIO does not interfere with cell viability or proliferation. The iron is located both intracellularly and extracellularly as iron clusters associated with the exterior of the cell membrane. Despite thorough washing, the extracellular SPIO remained associated with the cell membrane. The liposomal transfection agent does not change the maximum achievable cellular iron content but promotes a faster iron uptake. The MRI detectability persists for at least 7 days.Conclusion:The transfection agent DOSPER facilitates the efficient labeling of human metastatic melanoma cells with Resovist. Our findings raise the possibility that other Resovist-labeled cells may collect associated extracellular nanoparticles. The SPIO may be available to other iron-handling cells and not completely compartmentalized during the labeling procedure.

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Section: Discussionsupporting

confidence: 93%

Section: Methodsmentioning

confidence: 99%

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Labeling Human Melanoma Cells With SPIO

et al. 2016

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“…The physical size of the cell aggregation was presumed to extend over several imaging voxels. Recent studies have shown that labelled cells can aggregate in spherical cluster (Daldrup-Link et al 2003, Jendelova et al 2003, Pintaske et al 2005. Consequently, the present restriction to spherical geometries is no major limitation.…”

Section: General Considerationsmentioning

confidence: 95%

“…The ability of MRI to visualize aggregations of thousands to millions of SPIO-labelled cells has attracted much attention in the past few years (Bos et al 2004, Daldrup-Link et al 2005, Himes et al 2004, Hoehn et al 2002, Jendelova et al 2003. Aggregations of labelled cells are reflected either as low-intensity signal spots or signal voids, particularly in T * 2 -weighted gradient echo MRI (De Vries et al 2005, Hauger et al 2006, Pintaske et al 2005, Zhang et al 2004. It is important to know that localized MR signal loss can be caused by tissue-specific magnetic field inhomogeneities, which mimic the appearance of labelled cells under in vivo conditions.…”

Section: Introductionmentioning

confidence: 99%

Geometry and extension of signal voids in MR images induced by aggregations of magnetically labelled cells

Pintaske

Müller‐Bierl²,

Schick³

2006

Phys. Med. Biol.

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The ability of magnetic resonance imaging (MRI) to visualize magnetically labelled cells has attracted much attention for revealing cellular events. The present study addressed the geometry and the extension of signal voids in static signal dephasing MRI induced by aggregations of magnetically labelled cells by means of a three-dimensional numerical model. The magnetic field distortions around spherical cell aggregations were treated as equivalent to those of a magnetic dipole. Intravoxel signal dephasing and respective signal voids attributed to these field inhomogeneities were computed. Effects of cell concentration on the signal void in the plane of view were evaluated in terms of dipole magnetization. Signal void characteristics were scrutinized systematically for fundamental sequence parameters including echo time, voxel size and plane-of-view orientation. For all variables examined, significant changes in geometry as well as extension of signal voids were demonstrated. The results are of crucial importance to optimize and interpret MR images with regard to spatial accuracy as well as sensitivity to detect aggregations of labelled cells in vitro or even in vivo. It is anticipated that the dependence of the extension of signal voids on the local magnetization may be valuable for quantifying labelled cells.

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Determination of liver‐specific r₂* of a highly monodisperse USPIO by ⁵⁹Fe iron core‐labeling in mice at 3 T MRI

Raabe

Forberich

Freund

et al. 2014

Contrast Media & Molecular

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Accurate determination of tissue concentration of ultrasmall superparamagnetic iron oxide nanoparticles (USPIO) using T2 * MR relaxometry is still challenging. We present a reliable quantification method for local USPIO amount with the estimation of the liver specific relaxivity r2 * using monodisperse (59) Fe-core-labeled USPIO ((59) FeUSPIO). Dynamic and relaxometric in vivo characteristics of unlabeled monodisperse USPIO were determined in MRI at 3 T. The in vivo MR studies were performed for liver tissue with (59) FeUSPIO using iron dosages of 9 (n = 3), 18 (n = 2) and 27 (n = 3) µmol Fe kg(-1) body weight. The R2 * of the liver before and after USPIO injection (∆R2 *) was measured and correlated with (59) Fe activity measurements of excised organs by a whole body radioactivity counter (HAMCO) to define the dependency of ∆R2 * and (59) FeUSPIO liver concentration and calculate the r2 * of (59) FeUSPIO for the liver. Ultrastructural analysis of liver uptake was performed by histology and transmission electron microscopy. ∆R2 * of the liver revealed a dosage-dependent accumulation of (59) FeUSPIO with a percentage uptake of 70-88% of the injection dose. Hepatic ∆R2 * showed a dose-dependent linear correlation to (59) FeUSPIO activity measurements (r = 0.92) and an r2 * in the liver of 481 ± 74.9 mm(-1) s(-1) in comparison to an in vitro r2 * of 60.5 ± 3.3 mm(-1) s(-1) . Our results indicate that core-labeled (59) FeUSPIO can be used to quantify the local amount of USPIO and to estimate the liver-specific relaxivity r2 *.

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Eine Präparationstechnik zur quantitativen Untersuchung SPIO-haltiger Lösungen und SPIO-markierter Zellen in der MRT / A preparation technique for quantitative investigation of SPIO-containing solutions and SPIO-labelled cells by MRI

Cited by 8 publications

References 20 publications

Labeling Human Melanoma Cells With SPIO

Labeling Human Melanoma Cells With SPIO

Geometry and extension of signal voids in MR images induced by aggregations of magnetically labelled cells

Determination of liver‐specific r₂* of a highly monodisperse USPIO by ⁵⁹Fe iron core‐labeling in mice at 3 T MRI

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Eine Präparationstechnik zur quantitativen Untersuchung SPIO-haltiger Lösungen und SPIO-markierter Zellen in der MRT / A preparation technique for quantitative investigation of SPIO-containing solutions and SPIO-labelled cells by MRI

Cited by 8 publications

References 20 publications

Labeling Human Melanoma Cells With SPIO

Labeling Human Melanoma Cells With SPIO

Geometry and extension of signal voids in MR images induced by aggregations of magnetically labelled cells

Determination of liver‐specific r2* of a highly monodisperse USPIO by 59Fe iron core‐labeling in mice at 3 T MRI

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Determination of liver‐specific r₂* of a highly monodisperse USPIO by ⁵⁹Fe iron core‐labeling in mice at 3 T MRI