Quantification of magnetic nanocomposites in biological tissue through a cross-calibration of X-ray and Magnetic Resonance Imaging with the help of a uniform phantom

磁性药物靶向治疗(MDT)和磁热治疗(MHT)等微创肿瘤治疗的成功与否，在很大程度上依赖于磁性纳米粒子在一侧的正确分布。另一方面，这取决于携带药物的磁性纳米颗粒在靶区积累的事实。本研究项目的目的是利用MRI和XCT技术分析和量化生物组织中三维磁性纳米复合材料(MNC)的分布，从而确定最准确和一致的MNC定量方法。需要磁性纳米复合材料定量来分析MDT、MHT过程中的药物分布，或者为手术提供增强对比度。这对患者是有益的，因为诊断可以更准确和及时，减少出错的可能性和代价高昂的低效。联合使用X-CT和MRI可以增加定量成像的信息量，增强定量成像的有效效果。三维MNC量化应通过XCT和MRI的交叉校准进行。为此，申请人在2014年DFG赞助的研究奖学金期间开发了一种适用于MRI和XCT的长期稳定的体模系统，并进行了应用和测试。结果是一个核磁共振成像设备和一个XCT设备的规格范围。这种长期使用的体模需要改进，以适应临床日间使用。从而将其工作温度130°C等参数降至最高。40℃，MNC分布的均质性有待提高。在对已建立的体模系统进行修改后，将使用由生物组织和单核细胞组成的体模对新的体模进行验证。随后的MRI和XCT设备的交叉校准将与由生物组织和MNC组成的长期体模和体模进行，所获得的结果将是利用标准成像技术从三维数据中三维量化MNC的含量及其生物分布。因此，可以将MRI数据集和XCT数据集的灰度值分配给MNC浓缩值。然后，量化的结果可以应用于各种生物医学应用，其中磁性纳米颗粒发挥着关键作用。

The success of the minimal invasive cancer therapies, such as magnetic drug targeting (MDT) and magnetic heating treatment (MHT), depends strongly on the correct distribution of the magnetic nanoparticles on one side. On the other side it depends on the fact that a sufficient amount of magnetic nanoparticles carrying drugs is accumulated in the target region.The aim of this particular research project is to analyse and quantify 3-dimensionally magnetic nanocomposites (MNC) distributions within biological tissue using both MRI and XCT technologies, and thus determine the most accurate and consistent methodology for MNC quantification. Magnetic nanocomposite quantification would be required to analyse drug distribution during MDT, MHT or for providing enhanced contrast for surgery. This is beneficial to the patient as diagnosis can be more accurate and timely, reducing the potential for mistakes and costly inefficiencies. Use of both, XµCT and MRI, in combination could increase the information attained and enhance the effective impact of the quantitative imaging.The 3-dimensional MNC-quantification shall be performed by a cross-calibration of XCT and MRI. For this a long-term stable phantom system suitable for MRI and XCT was developed, applied and tested by the applicant during a DFG sponsored research fellowship in 2014. The result was a specification range of an MRI- and an XCT-equipment. This long-term phantom needs to be improved towards its applicability in the clinical day use. Thereby parameters as its working temperature of 130 °C shall be reduced to max. 40 °C and the homogeneity of the MNC distribution needs to be improved. After the modification of the established phantom system, the new phantoms will be verified with phantoms consisting of biological tissue and MNC. The subsequent cross-calibration of MRI- and XCT equipments will be performed with the long-term phantoms and phantoms made of biological tissue and MNC.The gained result will be a 3-dimensional quantification of the MNC content and their biodistribution out of 3-dimensionl data with a standard imaging techniques. Thereby grey values of the MRI- and XCT data sets can be assigned to MNC concentration values. The outcome of the quantification can then be applied to various biomedical applications where magnetic nanoparticles play a key role.