PET imaging with β-amyloid ligands is emerging as a molecular imaging technique targeting white matter integrity and demyelination. β-amyloid PET ligands such as ¹¹C-Pittsburgh compound B (¹¹C-PiB) have been considered for quantitative measurement of myelin content changes in multiple sclerosis, but ¹¹C-PiB is not commercially available given its short half-life. A ¹⁸F PET ligand such as flutemetamol with a longer half-life may be an alternative, but its ability to differentiate white matter hyperintensities (WMH) from normal-appearing white matter (NAWM) and its relationship with age remains to be investigated. Methods: Cognitively unimpaired (CU) older and younger adults (n = 61) were recruited from the community responding to a study advertisement for β-amyloid PET. Participants prospectively underwent MRI, ¹¹C-PiB, and ¹⁸F-flutemetamol PET scans. MRI fluid-attenuated inversion recovery images were segmented into WMH and NAWM and registered to the T1-weighted MRI. ¹¹C-PiB and ¹⁸F-flutemetamol PET images were also registered to the T1-weighted MRI. ¹¹C-PiB and ¹⁸F-flutemetamol SUV ratios (SUVrs) from the WMH and NAWM were calculated using cerebellar crus uptake as a reference for both ¹¹C-PiB and ¹⁸F-flutemetamol. Results: The median age was 38 y (range, 30–48 y) in younger adults and 67 y (range, 61–83 y) in older adults. WMH and NAWM SUVrs were higher with ¹⁸F-flutemetamol than with ¹¹C-PiB in both older (P < 0.001) and younger (P < 0.001) CU adults. ¹¹C-PiB and ¹⁸F-flutemetamol SUVrs were higher in older than in younger CU adults in both WMH (P < 0.001) and NAWM (P < 0.001). ¹¹C-PiB and ¹⁸F-flutemetamol SUVrs were higher in NAWM than WMH in both older (P < 0.001) and younger (P < 0.001) CU adults. There was no apparent difference between ¹¹C-PiB and ¹⁸F-flutemetamol SUVrs in differentiating WMH from NAWM in older and in younger adults. Conclusion: ¹¹C-PiB and ¹⁸F-flutemetamol show a similar topographic pattern of uptake in white matter with a similar association with age in WMH and NAWM. ¹¹C-PiB and ¹⁸F-flutemetamol can also effectively distinguish between WMH and NAWM. However, given its longer half-life, commercial availability, and higher binding potential, ¹⁸F-flutemetamol can be an alternative to ¹¹C-PiB in molecular imaging studies specifically targeting multiple sclerosis to evaluate white matter integrity.

β-淀粉样蛋白配体 PET 成像正在成为一种针对白质完整性和脱髓鞘的分子成像技术。β-淀粉样蛋白 PET 配体，如¹¹ C-匹兹堡化合物 B ( ¹¹ C-PiB) 已被考虑用于定量测量多发性硬化症中髓磷脂含量的变化，但¹¹ C-PiB 由于其半衰期短而无法商业化。半衰期较长的 18 F PET 配体（例如氟替他莫）可能是一种替代方案，但其区分白质高信号 (WMH) 与正常白质 (NAWM) 的能力及其与年龄的关系仍有待^研究。方法：从社区中招募认知未受损 (CU) 的老年人和年轻人 ( n = 61)，响应 β-淀粉样蛋白 PET 研究广告。参与者前瞻性地接受了 MRI、¹¹ C-PiB 和¹⁸ F-氟替他莫 PET 扫描。MRI 流体衰减反转恢复图像被分割为 WMH 和 NAWM 并配准到 T1 加权 MRI。¹¹ C-PiB 和¹⁸ F-氟替他莫 PET 图像也与 T1 加权 MRI 配准。^{使用小脑小腿摄取作为11} C-PiB 和¹⁸ F-氟替他莫的参考来计算来自 WMH 和 NAWM 的¹¹ C-PiB 和¹⁸ F-氟替他莫 SUV 比率 (SUVrs)。结果：年轻人的中位年龄为 38 岁（范围，30-48 岁），老年人的中位年龄为 67 岁（范围，61-83 岁）。在老年 ( P < 0.001) 和年轻 ( P < 0.001) CU 成人中， ¹⁸ F-氟替他莫组的WMH 和 NAWM SUVr 均高于^{11 C-PiB。}在 WMH ( P < 0.001) 和 NAWM ( P < 0.001)方面，老年人¹¹ C-PiB 和¹⁸ F-氟替他莫 SUVr 均高于年轻 CU 成人。在老年 ( P < 0.001) 和年轻 ( P < 0.001) CU 成人中，NAWM 中¹¹ C-PiB 和¹⁸ F-氟替他莫 SUVr 均高于 WMH 。¹¹ C-PiB 和¹⁸ F-氟替他莫 SUVr 在区分老年人和年轻人的 WMH 和 NAWM 方面没有明显差异。结论：¹¹ C-PiB 和¹⁸ F-氟替他莫在白质中显示出相似的摄取拓扑模式，并且在 WMH 和 NAWM 中与年龄具有相似的相关性。¹¹ C-PiB 和¹⁸ F-氟替他莫还可以有效区分 WMH 和 NAWM。然而，鉴于其较长的半衰期、商业可用性和较高的结合潜力，在专门针对多发性硬化症以评估白质完整性的分子成像研究中，¹⁸ F-氟替他莫可以替代^{11 C-PiB。}