Choi Chang-Hoon, Stegmayr Carina, Shymanskaya Aliaksandra, Worthoff Wieland A, da Silva Nuno A, Felder Jörg, Langen Karl-Josef, Shah N Jon
Institute of Neuroscience and Medicine-4, INM-4, Forschungszentrum Jülich, Germany.
Institute of Neuroscience and Medicine-11, INM-11, JARA, Forschungszentrum Jülich, Germany.
EJNMMI Phys. 2020 Jul 29;7(1):50. doi: 10.1186/s40658-020-00319-6.
In addition to the structural information afforded by H MRI, the use of X-nuclei, such as sodium-23 (Na) or phosphorus-31 (P), offers important complementary information concerning physiological and biochemical parameters. By then combining this technique with PET, which provides valuable insight into a wide range of metabolic and molecular processes by using of a variety of radioactive tracers, the scope of medical imaging and diagnostics can be significantly increased. While the use of multimodal imaging is undoubtedly advantageous, identifying the optimal combination of these parameters to diagnose a specific dysfunction is very important and is advanced by the use of sophisticated imaging techniques in specific animal models.
In this pilot study, rats with intracerebral 9L gliosarcomas were used to explore a combination of sequential multinuclear MRI using a sophisticated switchable coil set in a small animal 9.4 T MRI scanner and, subsequently, a small animal PET with the tumour tracer O-(2-[F]-fluoroethyl)-L-tyrosine ([F]FET). This made it possible for in vivo multinuclear MR-PET experiments to be conducted without compromising the performance of either multinuclear MR or PET.
High-quality in vivo images and spectra including high-resolution H imaging, Na-weighted imaging, detection of P metabolites and [F]FET uptake were obtained, allowing the characterisation of tumour tissues in comparison to a healthy brain. It has been reported in the literature that these parameters are useful in the identification of the genetic profile of gliomas, particularly concerning the mutation of the isocitrate hydrogenase gene, which is highly relevant for treatment strategy.
The combination of multinuclear MR and PET in, for example, brain tumour models with specific genetic mutations will enable the physiological background of signal alterations to be explored and the identification of the optimal combination of imaging parameters for the non-invasive characterisation of the molecular profile of tumours.
除了氢磁共振成像（H MRI）提供的结构信息外，使用诸如钠 - 23（Na）或磷 - 31（P）等X核，可提供有关生理和生化参数的重要补充信息。通过将该技术与正电子发射断层扫描（PET）相结合，PET利用各种放射性示踪剂对广泛的代谢和分子过程提供有价值的见解，医学成像和诊断的范围可显著扩大。虽然使用多模态成像无疑具有优势，但确定这些参数的最佳组合以诊断特定功能障碍非常重要，并且通过在特定动物模型中使用先进的成像技术得以推进。
在这项初步研究中，使用患有脑内9L胶质肉瘤的大鼠，在小动物9.4 T磁共振成像扫描仪中，利用一套精密的可切换线圈，探索顺序多核磁共振成像与随后使用肿瘤示踪剂O -（2 - [F] - 氟乙基）- L - 酪氨酸（[F]FET）的小动物PET的组合。这使得在不影响多核磁共振成像或PET性能的情况下进行体内多核磁共振 - 正电子发射断层扫描实验成为可能。
获得了高质量的体内图像和光谱，包括高分辨率氢成像、钠加权成像、磷代谢物检测和[F]FET摄取情况，从而能够将肿瘤组织与健康脑进行对比表征。文献报道这些参数有助于识别胶质瘤的基因谱，特别是与异柠檬酸脱氢酶基因突变有关，这与治疗策略高度相关。
例如，在具有特定基因突变的脑肿瘤模型中，多核磁共振成像和正电子发射断层扫描的结合将能够探索信号改变的生理背景，并确定用于无创表征肿瘤分子谱的成像参数的最佳组合。
