The development of sensitive probes for directly measuring in vivo processes is at the forefront of medical imaging. In the case of magnetic resonance imaging (MRI) the detection of a small number of molecules is a major challenge due to its limited sensitivity. This problem can be tackled by hyperpolarization, which increases the NMR signals up to several orders of magnitude. In this contribution NMR hyperpolarization of non‐radioactive counterparts of two well‐established positron emission tomography (PET) tracers, namely O‐(2‐[¹⁸F]fluoroethyl)‐l‐tyrosine ([¹⁸F]FET) and [¹⁸F]fallypride ([¹⁸F]FP), via para‐hydrogen induced polarization (PHIP), to investigate oncological and neurological questions is demonstrated. Significant ¹H/¹³C NMR signal enhancements of several thousand were achieved for both tracers. Partial deuteration of the ¹³C‐labeled [¹⁸F]FET analog resulted in T₁ times up to ∼36 s. Hence, this molecule is a candidate for an MRI contrast agent, allowing follow‐up MRI examinations with close succession in time.

中文翻译：

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既定PET示踪剂的NMR超极化

用于直接测量体内过程的敏感探针的开发处于医学成像的最前沿。在磁共振成像（MRI）的情况下，由于灵敏度有限，因此检测少量分子是一项重大挑战。这个问题可以通过超极化来解决，它可以将NMR信号增加几个数量级。在这项贡献中，两个公认的正电子发射断层扫描（PET）示踪剂的非放射性对应物的NMR超极化，即O-（2- [ ¹⁸ F]氟乙基）-1-酪氨酸（[ ¹⁸ F] FET）和[ ¹⁸ F ] fallypride（[ ¹⁸F] FP），通过对氢诱导极化（PHIP）来研究肿瘤学和神经学问题。两种示踪剂均实现了数千次的显着¹ H / ¹³ C NMR信号增强。¹³ C标记的[ ¹⁸ F] FET类似物的部分氘化导致T ₁倍，直至〜36 s。因此，该分子可作为MRI造影剂的候选者，从而可以及时进行连续的MRI检查。