Kawai Nobuyuki, Okauchi Masanobu, Miyake Keisuke, Sasakawa Yasuhiro, Yamamoto Yuka, Nishiyama Yoshihiro, Tamiya Takashi
Department of Neurological Surgery, Faculty of Medicine, Kagawa University, Kagawa, Japan.
No Shinkei Geka. 2010 Nov;38(11):985-95.
Positron emission tomography (PET) with L-[methyl-11C]methionine (MET) provides information on the metabolism of brain tumor. MET uptake reflects amino acid active transport and protein synthesis and is proportional to the amount of viable tumor cells. However, MET uptake can be increased as a result of increased density of inflammatory cells and disruption of the blood brain barrier (BBB) in nontumorous brain lesions. From October 2005 through November 2009, 438 MET-PET studies were performed for various brain lesions at our institution. Among them, 27 (6%) were finally diagnosed to be nontumorous by surgical exploration or their clinical course. Nine of 10 intracerebral hemorrhages and all 4 cerebral infarctions demonstrated mild to moderate MET uptake in or surrounding the lesions in the subacute or chronic stage after the ictus. Moderately increased MET uptake was observed in all 3 patients with brain abscess. Active lesions in multiple sclerosis and Beçhet disease showed mild MET uptake. Idiopathic orbital and optic inflammations showed mildly increased MET uptake in the lesions. Finally, a case of hypertrophic cranial pachymeningitis exhibited strong MET uptake in the lesions. We should keep in mind that high MET uptake is frequently observed in nontumorous brain lesions. Although differentiation from tumorous lesions is usually possible by laboratory and morphological examinations, nontumorous lesions should be included in the differential diagnosis when encountering patients with high MET uptake.
使用L-[甲基-¹¹C]蛋氨酸（MET）的正电子发射断层扫描（PET）可提供有关脑肿瘤代谢的信息。MET摄取反映氨基酸的主动转运和蛋白质合成，并且与存活肿瘤细胞的数量成正比。然而，在非肿瘤性脑病变中，由于炎症细胞密度增加和血脑屏障（BBB）破坏，MET摄取可能会增加。从2005年10月到2009年11月，我们机构对各种脑病变进行了438项MET-PET研究。其中，27例（6%）最终通过手术探查或其临床病程被诊断为非肿瘤性病变。10例脑内出血中有9例以及所有4例脑梗死在发病后的亚急性或慢性期病变内或周围显示出轻度至中度的MET摄取。3例脑脓肿患者均观察到MET摄取中度增加。多发性硬化症和白塞病的活动病变显示出轻度的MET摄取。特发性眼眶和视神经炎症在病变中显示出MET摄取轻度增加。最后，1例肥厚性硬脑膜炎患者的病变表现出强烈的MET摄取。我们应该记住，在非肿瘤性脑病变中经常观察到高MET摄取。虽然通常可以通过实验室和形态学检查与肿瘤性病变进行鉴别，但在遇到MET摄取高的患者时，非肿瘤性病变应包括在鉴别诊断中。
