Jiménez Bonilla J F, Carril Carril J M
Servicio de Medicina Nuclear, Hospital "Marqués de Valdecilla", Universidad de Cantabria, Santander, España.
Rev Esp Med Nucl Imagen Mol. 2013 Sep-Oct;32(5):301-9. doi: 10.1016/j.remn.2013.06.012. Epub 2013 Aug 9.
In the context of the limitations of structural imaging, brain perfusion and metabolism using SPECT and PET have provided relevant information for the study of cognitive decline. The introduction of the radiotracers for cerebral amyloid imaging has changed the diagnostic strategy regarding Alzheimer's disease, which is currently considered to be a "continuum." According to this new paradigm, the increasing amyloid load would be associated to the preclinical phase and mild cognitive impairment. It has been possible to observe "in vivo" images using 11C-PIB and PET scans. The characteristics of the 11C-PIB image include specific high brain cortical area retention in the positive cases with typical distribution pattern and no retention in the negative cases. This, in combination with 18F-FDG PET, is the basis of molecular neuroimaging as a biomarker. At present, its prognostic value is being evaluated in longitudinal studies. 11C-PIB-PET has become the reference radiotracer to evaluate the presence of cerebral amyloid. However, its availability is limited due to the need for a nearby cyclotron. Therefore, 18F labeled radiotracers are being introduced. Our experience in the last two years with 11C-PIB, first in the research phase and then as being clinically applied, has shown the utility of the technique in the clinical field, either alone or in combination with FDG. Thus, amyloid image is a useful tool for the differential diagnosis of dementia and it is a potentially useful method for early diagnosis and evaluation of future treatments.
在结构成像存在局限性的背景下，利用单光子发射计算机断层扫描（SPECT）和正电子发射断层扫描（PET）进行的脑灌注和代谢研究为认知衰退的研究提供了相关信息。用于脑淀粉样蛋白成像的放射性示踪剂的引入改变了关于阿尔茨海默病的诊断策略，目前阿尔茨海默病被认为是一个“连续体”。根据这一新范式，淀粉样蛋白负荷的增加与临床前阶段和轻度认知障碍相关。使用11C-匹兹堡化合物B（11C-PIB）和PET扫描已经能够观察到“活体”图像。11C-PIB图像的特征包括在阳性病例中特定的高脑皮质区域滞留，具有典型的分布模式，而在阴性病例中无滞留。这与18F-氟代脱氧葡萄糖（18F-FDG）PET相结合，是分子神经成像作为生物标志物的基础。目前，其预后价值正在纵向研究中进行评估。11C-PIB-PET已成为评估脑淀粉样蛋白存在的参考放射性示踪剂。然而，由于需要附近有回旋加速器，其可用性有限。因此，正在引入18F标记的放射性示踪剂。我们在过去两年中使用11C-PIB的经验，首先是在研究阶段，然后是临床应用，已经表明该技术在临床领域单独使用或与FDG联合使用时的效用。因此，淀粉样蛋白成像对于痴呆的鉴别诊断是一种有用的工具，并且对于早期诊断和未来治疗的评估是一种潜在有用的方法。
