发作间期PET显像与发作期SPECT显像在癫痫灶定位中的应用

目的：探讨发作间期PET显像与发作期SPECT显像在癫痫灶定位中的特点和相关性。方法：对54例癫痫患者行发作间期PET和发作期SPECT2次检查，对结果进行对比分析。结果：54例发作间期PET显像示低代谢者中33例（61．1％）表现为单叶局限性低代谢，21例（38．9％）表现为多个病灶或弥漫性改变。发作期SPECT显像50例可见高灌注灶，高灌注中37例（74％）为单叶局限性高灌注，13例（26％）为多个病灶，未见弥漫性高灌注。2项检查比较，46例（85．2％）2项检查结果相符合，其中32例（69．6％）显示为颞叶病灶。发作间期PET示多病灶及弥漫性改变者于发作期SPECT为像时为9例（42．9％）转化为单叶局限性病灶，7例（33．3％）排除了部分低代谢病灶。结论：癫痫灶灌注与代谢改变具有明显的相关性。发作间期PET显像定位癫痫灶解剖结构显示较为清晰，发作期SPECT显像替代发作期PET检查可提高定位特异。2项检查联合应用可排除非致痫性病变和发作过程中痫性电活动的泛化，具有较好的互补性。

Associated application studies of epileptic interictal PET and ictal SPECT brain imaging

Objective To evaluate the value of interictal PET and ictal SPECT brain imaging in the localization of epileptic foci. Methods Fifty-four patients with epilepsy were examined with PET in ictal phase and with SPECT in interictal phase. The results were compared and analysed. Results During interictal PET studies, 33 (61.1%) patients had solitary focal hypo-metabolic foci, 21(38.9%) patients showed multi-lobar or diffuse hypometabolism. During ictal SPECT studies, 50 patients showed cerebral hyper-perfusion compared to the same area in interictal phase. 37 (74%) patients had solitary focal hyper-perfusive foci. 13 (26%) patients showed multiple hyper-perfusion, no diffuse hyper-perfusion was observed. Compared the two examinations, in 46(85.2%) patients the foci found by the two examinations were similar and in 32(69.6%) among them the foci were found in temporal lobe. Of the 21 patients with multi-lobar or diffuse hypo-metabolism, in 9 (42.9%) patients their foci changed to solitary focal hyper-perfusion, and in 7 ( 33.3%) patients their focal partial hypometabolic foci were excluded in ictal SPECT studies. Conclusions High correlation of blood flow perfusion and glucose metabolism was found in one patient. Interictal PET imaging gave lower specificity and false epileptic foci but displayed clear anatomic structure. Ictal SPECT imaging is of higher specificity and can supersede the ictal PET imaging. When the two scans are used together, the epileptic dissemination and the non-epileptic foci could be avoided, the specificity and accuracy for the localization of epileptic foci could be elevated.