PET／fMRI对异常脑活动的精准定位：研究进展与展望

PET/fMRI for precise localization of abnormal brain activity： a mini review

许多脑疾病无明显病灶，其病因可能是源于脑活动或脑区连通性的异常。目前常用的脑成像诊断技术很难对其异常脑活动进行精准定位。新近发展起来的PET/MR一体同步显像技术或能弥补此缺陷。该设备已经用于临床诊断，但主要还是利用了PET功能影像与MRI结构影像的结合，远远没有发挥其＂功能－功能＂结合的诸多优势。目前，国际上PET/fMRI的研究尚处于起步阶段。初步研究表明，PET与fMRI常用功能指标之间的相关性并不高，提示2种功能指标可能揭示了不同的生理、病理机制。目前，我国大型研究型医院已经安装了至少5台一体化PET/MR设备。相对来说，我国的优势在于病源充足，PET影像发展迅速，且在fMRI的计算方法学方面有较高的国际地位。PET/fMRI的研究通常需要多学科的合作，包括核医学、放射学、化学、医用物理学、影像计算方法学、认知神经科学等等，我国医院的科研管理体制还需要改进，以满足这种多学科高度交叉合作的需求。利用自身优势，改进自身科研管理体制，再加上多中心合作，相信我国在PET/fMRI的研究方面能够很快达到国际一流水平，并取得既有科学价值、又有临床价值的科研成果。

Many brain disorders do not show visible lesions and most likely are resulted from abnormalities in regional brain activity or connectivity. Conventional diagnostic neuroimaging techniques are not capable of precisely localizing the abnormal brain activity, but the recently developed integrated PET/MR technology may have the potential to bridge this gap. Integrated PET/MR has been used in clinical practice. However, its primary application is still a combination of functional PET imaging and structural MRI. Simultaneous PET/fMRI, a ＂ functional＋ functional＂ imaging technique, holds the advantages of high spatial and temporal resolution, high sensitivity and specificity, and non-invasiveness. Globally, simultaneous PET/fMRI research is still in its beginning stage, and a few initial PET/fMRI studies have shown that voxel-wise correlation between PET and fMRI metrics was not very high, indicating that they may reflect very different aspects of brain activity. To date more than 5 integrated PET/MR scanners have been set up in China's Mainland. China has the largest patient population, rapidly developing PET imaging techniques, and well-established capabilities in fMRI neuroimaging analytics. PET/fMRI studies require multi-disciplinary collaborations in nuclear medicine, radiology, chemistry, medical physics, computation science, and cognitive neuroscience. At the moment, the research management system in Chinese hospitals is not conducive to such collaborations and further improvement is needed to encourage multi-disciplinary research such as PET/fMRI. Given the known advantages in patient population and other resources, multi-center and multi-disciplinary studies hold the potential to put China at the leading edge of PET/fMRI research and produce high value results that will advance both neuroimaging sciences and future patient care in brain disorders.