Division of Nuclear Medicine, Department of Medical Imaging, Centre Hospitalier Universitaire Sainte-Justine, 3175 Chemin de la Côte-Sainte-Catherine, Montréal, Québec, H3T 1C5, Canada.
Department of Nuclear Medicine, Health Sciences Centre, University of Manitoba, Winnipeg, Manitoba, Canada.
Eur J Nucl Med Mol Imaging. 2019 Jun;46(6):1309-1324. doi: 10.1007/s00259-019-04302-x. Epub 2019 Mar 12.
FDG PET/CT is emerging as a new tool for the evaluation of acute encephalitis (AE). However, to date, there are no exclusively pediatric studies on the use of FDG PET for suspected AE. The objective of this study was to compare qualitative and quantitative brain PET to conventional brain imaging in a cohort of children, and to identify patterns of metabolic abnormalities characteristic of AE.
This retrospective study included 34 children imaged with PET/CT, CT and magnetic resonance imaging (MRI). The positivity rate of all three imaging modalities was measured. Besides visual assessment, quantification of relative regional brain metabolism (RRBM) was performed and compared to a database of normal pediatric brains.
Fourteen subjects had a clinical diagnosis of autoimmune encephalitis (AIE) or encephalitis of unknown origin (EX), six of anti-N-methyl-D-aspartate receptor (anti-NMDAr) encephalitis, three of Hashimoto's encephalopathy, three of neurolupus and eight had other subtypes of encephalitis. Quantitative PET was abnormal in 100% of cases, visually assessed PET in 94.1% of subjects, MRI in 41.2% and CT in 6.9%. RRBM quantification demonstrated multiple hyper and hypo metabolic cortical regions in 82.3% of subjects, exclusively hypermetabolic abnormalities in 3%, and exclusively hypometabolic abnormalities in 14.7%. The basal ganglia were hypermetabolic in 26.5% of cases on visual assessment and in 58.8% of subjects using quantification.
In our pediatric population FDG PET was more sensitive than conventional imaging for the detection of AE, and basal ganglia hypermetabolism was frequently encountered.
正电子发射断层扫描/计算机断层扫描（FDG PET/CT）作为评估急性脑炎（AE）的新工具正在兴起。然而，迄今为止，尚无专门针对疑似 AE 使用 FDG PET 的儿科研究。本研究的目的是比较疑似 AE 患儿的脑 FDG PET 与常规脑成像的定性和定量结果，并确定符合 AE 特征的代谢异常模式。
本回顾性研究纳入了 34 例接受 PET/CT、CT 和磁共振成像（MRI）检查的患儿。测量了三种成像方式的阳性率。除了视觉评估外，还进行了相对区域性脑代谢（RRBM）的定量，并与正常儿科脑数据库进行了比较。
14 例患儿临床诊断为自身免疫性脑炎（AIE）或原因不明脑炎（EX），其中 6 例为抗 N-甲基-D-天冬氨酸受体（anti-NMDAr）脑炎，3 例为桥本脑病，3 例为神经狼疮，8 例为其他类型脑炎。定量 PET 异常见于 100%的病例，94.1%的患儿 PET 视觉评估异常，41.2%的 MRI 异常，6.9%的 CT 异常。RRBM 定量显示 82.3%的患儿有多个皮质区高代谢和低代谢，3%的患儿仅有高代谢异常，14.7%的患儿仅有低代谢异常。视觉评估时基底节高代谢见于 26.5%的病例，定量时见于 58.8%的患儿。
在我们的儿科人群中，FDG PET 比常规成像更敏感，可用于检测 AE，并且基底节高代谢很常见。
