Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China.
Epilepsy Center, Cleveland Clinic, Cleveland, OH, USA.
Epilepsia. 2018 Aug;59(8):1583-1594. doi: 10.1111/epi.14474. Epub 2018 Jun 28.
Detection of focal cortical dysplasia (FCD) is of paramount importance in epilepsy presurgical evaluation. Our study aims at utilizing quantitative positron emission tomography (QPET) analysis to complement magnetic resonance imaging (MRI) postprocessing by a morphometric analysis program (MAP) to facilitate automated identification of subtle FCD.
We retrospectively included a consecutive cohort of surgical patients who had a negative preoperative MRI by radiology report. MAP was performed on T1-weighted volumetric sequence and QPET was performed on PET/computed tomographic data, both with comparison to scanner-specific normal databases. Concordance between MAP and QPET was assessed at a lobar level, and the significance of concordant QPET-MAP abnormalities was confirmed by postresective seizure outcome and histopathology. QPET thresholds of standard deviations (SDs) of -1, -2, -3, and -4 were evaluated to identify the optimal threshold for QPET-MAP analysis.
A total of 104 patients were included. When QPET thresholds of SD = -1, -2, and -3 were used, complete resection of the QPET-MAP region was significantly associated with seizure-free outcome when compared with the partial resection group (P = 0.023, P < 0.001, P = 0.006) or the no resection group (P = 0.002, P < 0.001, P = 0.001). The SD threshold of -2 showed the best combination of positive rate (55%), sensitivity (0.68), specificity (0.88), positive predictive value (0.88), and negative predictive value (0.69). Surgical pathology of the resected QPET-MAP areas revealed mainly FCD type I. Multiple QPET-MAP regions were present in 12% of the patients at SD = -2.
Our study demonstrates a practical and effective approach to combine quantitative analyses of functional (QPET) and structural (MAP) imaging data to improve identification of subtle epileptic abnormalities. This approach can be readily adopted by epilepsy centers to improve postresective seizure outcomes for patients without apparent lesions on MRI.
在癫痫术前评估中，检测局灶性皮质发育不良（FCD）至关重要。我们的研究旨在利用定量正电子发射断层扫描（QPET）分析来补充磁共振成像（MRI）后处理，通过形态分析程序（MAP）来辅助自动识别细微的 FCD。
我们回顾性纳入了一组连续的手术患者，他们的术前 MRI 报告为阴性。在 T1 加权容积序列上进行 MAP，在 PET/CT 数据上进行 QPET，并与扫描仪特异性正常数据库进行比较。在叶水平评估 MAP 和 QPET 的一致性，并通过术后癫痫发作结果和组织病理学确认一致的 QPET-MAP 异常的意义。评估了 QPET 标准偏差（SD）的阈值-1、-2、-3 和-4，以确定 QPET-MAP 分析的最佳阈值。
共纳入 104 例患者。当使用 QPET 阈值 SD = -1、-2 和-3 时，与部分切除组（P = 0.023，P < 0.001，P = 0.006）或未切除组（P = 0.002，P < 0.001，P = 0.001）相比，完全切除 QPET-MAP 区域与无癫痫发作结果显著相关。SD 阈值为-2 时，阳性率（55%）、灵敏度（0.68）、特异性（0.88）、阳性预测值（0.88）和阴性预测值（0.69）的组合最佳。切除的 QPET-MAP 区域的手术病理主要为 FCD Ⅰ型。在 SD = -2 时，12%的患者存在多个 QPET-MAP 区域。
我们的研究表明，结合功能（QPET）和结构（MAP）成像数据的定量分析是一种实用且有效的方法，可以提高对细微癫痫异常的识别。这种方法可以很容易地被癫痫中心采用，以提高无明显 MRI 病变患者的术后癫痫发作结果。
