Institute of Inorganic and Analytical Chemistry, University of Münster, 48149 Münster, Germany.
Clinic of Radiology, University of Münster, 48149 Münster, Germany.
Metallomics. 2024 Aug 20;16(8). doi: 10.1093/mtomcs/mfae034.
A referencing strategy based on the element P is presented to compensate for cryosectioning tissue artifacts in laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) data. The study examines how the gadolinium-based contrast agent Gadofosveset is distributed in murine cancer tissue, and illustrates how referenced images can compensate for tissue artifacts like folds, overlaps, and density variations. Compared to non-referenced images that provide information on the absolute distribution of the analyte, referenced images allow for the representation of the analyte distribution relative to the amount of material introduced into the instrument, which in this case is correlated to the P signal. Tissue artifacts were corrected in referenced images for both Gadofosveset and endogenous elements, such as Fe and Zn. Additionally, the referencing approach provides valuable information on the Gd uptake relative to the tissue density in necrotic compared to vital tumor areas, which is not obtained from in vivo magnetic resonance imaging (MRI) data. However, validation of in vivo MRI and ex vivo LA-ICP-MS methods was possible by establishing a mean ratio of necrotic to vital tumor areas in the T1-weighted image post Gadofosveset injection and the non-referenced LA-ICP-MS image of Gd. In summary, P-based correction of LA-ICP-MS imaging data allows for a more accurate spatial representation of certain elements, including endogenous and exogenous elements such as injected contrast agents.
本文提出了一种基于 P 元素的参考策略，用于补偿激光烧蚀-电感耦合等离子体质谱（LA-ICP-MS）数据中冷冻切片组织伪影。该研究检查了钆基造影剂钆喷酸葡胺在小鼠癌症组织中的分布情况，并说明了参考图像如何补偿组织伪影，如褶皱、重叠和密度变化。与提供分析物绝对分布信息的非参考图像相比，参考图像允许表示分析物相对于引入仪器的材料量的分布，在这种情况下，与 P 信号相关。参考图像校正了钆喷酸葡胺和内源性元素（如铁和锌）的组织伪影。此外，参考方法提供了有关与坏死肿瘤区域相比，坏死肿瘤区域相对于组织密度的 Gd 摄取的有价值信息，这是从体内磁共振成像（MRI）数据中无法获得的。然而，通过在注射钆喷酸葡胺后 T1 加权图像和 Gd 的非参考 LA-ICP-MS 图像中建立坏死肿瘤区域与存活肿瘤区域的平均比值，对体内 MRI 和体外 LA-ICP-MS 方法进行了验证。总之，基于 P 的 LA-ICP-MS 成像数据校正允许更准确地表示某些元素的空间分布，包括内源性和外源性元素，如注入的造影剂。
