Nuclear Spin Singlet Lifetimes – A New Contrast Mechanism for Magnetic Resonance

核自旋单线态寿命——磁共振的新对比机制

• 批准号: 495627437
• 负责人: Dr. Stefan Glöggler
• 金额: --
• 依托单位: Klinik für Diagnostische und Interventionelle Radiologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/495627437?language=en
• 关键词: Nuclear; Spin; Singlet; Lifetimes; New

Oxygen is the fuel of life and in its absence, most cells and organisms die within minutes. Vascular cognitive impairment (VCI) is one common cause of dementia, i.e. vascular dementia. Ultimately, this disease originates from a compromised blood flow (hypoperfusion) and oxygen delivery (hypoxia) to the brain. Thus, accurate detection of blood oxygenation promises to be immensely helpful to better understand, identify and grade this pathology. A better insight into the emergence as well as early detection and accurate diagnosis of VCI are particularly important, also because vascular dementia is – at least partially – preventable. For an early diagnostics new scientific approaches can proof valuable.Therefore, we propose to research nuclear spin singlet states as an entirely new contrast mechanims for diagnostics in magnetic resonance (MR). As we have demonstrated in our preliminary work, singlet states can be populated in brain metabolites and its relaxation time – the singlet lifetime TS – can be measured with MR. The special feature about the singlet state is that TS is more sensitive to different relaxation phenomena than currently used MR contrast mechanisms (i.e. T1- and T2-weighted MR). Indeed, TS is dominated by paramagnetic relaxation. Consequently, we hypothesize that TS will proof itself as a novel parameter to probe the tissue environment and especially the presence of paramagnetic molecules in tissue in a currently non-existent way.MR is already one important diagnostic pillar for VCI as it is versatile, non-invasive, does not require ionizing radiation and is widely available in the clinics. Also paramagnetic changes are most relevant to VCI, because the fraction of paramagnetic deoxygenated hemoglobin in the blood increases and O2 decreases upon hypoperfusion and ischemia.Thus, as a first application of our novel approach, we envision that singlet states can be used to sensitively detect hypoxia in the brain in a VCI mouse model, the demonstration of which is subject to this proposal. To this end, we here tune the methodology and identify appropriate endogenous targets (metabolites) in a way that enables us to access TS in vivo sensitively. We research the lifetime of singlet states in vitro in test solutions, as well as in vivo in healthy and VCI mice. We anticipate the possibility of direct quantification of blood oxygenation from a single TS measurement.

氧气是生命的燃料，如果没有氧气，大多数细胞和生物会在几分钟内死亡。血管性认知障碍（VCI）是痴呆的一种常见原因，即血管性痴呆。最终，这种疾病起源于向大脑的血流受损（灌注不足）和氧气输送（缺氧）。因此，准确检测血氧有望极大地有助于更好地理解，识别和分级这种病理。更好地了解VCI的出现以及早期检测和准确诊断尤为重要，这也是因为血管性痴呆至少部分是可以预防的。新的科学方法对于早期诊断是有价值的，因此，我们提出研究核自旋单重态作为磁共振诊断的一种全新的对比机制。正如我们在我们的初步工作中所证明的那样，单重态可以在脑代谢物中填充，并且其弛豫时间-单重态寿命TS -可以用MR测量。关于单重态的特殊功能是TS对不同的弛豫现象比目前使用的MR对比机制（即T1和T2加权MR）更敏感。实际上，TS由顺磁弛豫主导。因此，我们假设TS将证明自己是一种新的参数，以探测组织环境，特别是顺磁分子在组织中的存在，在目前不存在的方式。MR已经是VCI的一个重要的诊断支柱，因为它是通用的，非侵入性的，不需要电离辐射，并在临床上广泛使用。顺磁性的变化也是最相关的VCI，因为血液中的顺磁性脱氧血红蛋白的分数增加和O2减少低灌注和ischemia. Therefore，作为我们的新方法的第一个应用程序，我们设想，单态可以用来灵敏地检测在大脑中的缺氧VCI小鼠模型，其中的演示是受本建议。为此，我们在这里调整的方法，并确定适当的内源性目标（代谢物）的方式，使我们能够在体内敏感地访问TS。我们研究了单重态在体外测试溶液中的寿命，以及在健康和VCI小鼠体内的寿命。我们预计从一个单一的TS测量直接定量血氧的可能性。