Peter Jonah, Khosravi Mohsen, Werner Thomas J, Alavi Abass
Department of Radiology, Division of Nuclear Medicine, Hospital of the University of Pennsylvania, USA.
Hell J Nucl Med. 2018 May-Aug;21(2):95-101. doi: 10.1967/s002449910800. Epub 2018 Jul 12.
The purpose of this study was to evaluate the utility of global semi-quantitative analysis via fluorine-18-flurodeoxyglucose positron emission tomography (F-FDG PET) at lateralizing seizure foci and diagnosing patients with unilateral temporal lobe epilepsy (TLE).
Seventeen patients with unilateral TLE (11 right TLE and 6 left TLE) were retrospectively selected for semi-quantitative F-FDG PET analysis. Twenty-three control subjects with a Mini Mental State Examination (MMSE) score of 29 or greater were selected for comparison. Globally averaged standardized uptake value (gSUVmean) was computed for each temporal lobe. Lateralization indices (LI) and the absolute value of lateralization indices (|LI|) were calculated to assess the degree of asymmetry in each subject. Logistic regression analyses were performed at a probability cutoff of 0.5 to classify TLE patients as left or right TLE and to discriminate patients from control subjects. Receiver operating characteristic (ROC) curves were generated to evaluate the utility of LI and |LI| as classification predictors. The Bland Altman test was used to evaluate the reproducibility of the measurements.
There was a statistically significant difference in gSUVmean computed LI between left and right TLE patients (P<0.01). There was no statistically significant difference in |LI| between the patient and control groups (P=0.22). Logistic regression revealed that 82% of TLE patients were lateralized correctly using LI as the sole predictor. The area under the ROC curve (AUC) was 0.80. Logistic regression using |LI| on the combined patient/control population showed a diagnostic accuracy of 65% and an AUC of 0.44. Bland Altman analysis revealed an intra-observer reproducibility of 96% and an inter-observer reproducibility of 96% and 91% on successive trials.
We conclude that gSUVmean computed LI is a reliable and reproducible measure for predicting seizure lateralization in unilateral TLE patients. However, gSUVmean computed |LI| does not appear to be particularly effective at diagnosing TLE patients from control subjects. Further studies with more patients should investigate other machine learning techniques that combine gSUVmean with other diagnostic predictors.
本研究旨在评估通过氟 - 18 - 氟脱氧葡萄糖正电子发射断层扫描（F - FDG PET）进行整体半定量分析在确定癫痫发作灶侧别以及诊断单侧颞叶癫痫（TLE）患者方面的效用。
回顾性选取17例单侧TLE患者（11例右侧TLE和6例左侧TLE）进行F - FDG PET半定量分析。选取23例简易精神状态检查表（MMSE）评分在29分及以上的对照受试者进行比较。计算每个颞叶的整体平均标准化摄取值（gSUVmean）。计算侧化指数（LI）及其绝对值（|LI|）以评估每个受试者的不对称程度。在概率截断值为0.5时进行逻辑回归分析，将TLE患者分类为左侧或右侧TLE，并将患者与对照受试者区分开来。生成受试者操作特征（ROC）曲线以评估LI和|LI|作为分类预测指标的效用。使用Bland Altman检验评估测量的可重复性。
左侧和右侧TLE患者计算得到的gSUVmean LI存在统计学显著差异（P<0.01）。患者组和对照组之间的|LI|无统计学显著差异（P = 0.22）。逻辑回归显示，以LI作为唯一预测指标时，82%的TLE患者侧别判断正确。ROC曲线下面积（AUC）为0.80。对患者/对照人群联合使用|LI|进行逻辑回归分析，诊断准确率为65%，AUC为0.44。Bland Altman分析显示，连续试验中观察者内可重复性为96%，观察者间可重复性分别为96%和91%。
我们得出结论，计算得到的gSUVmean LI是预测单侧TLE患者癫痫发作侧别的可靠且可重复的指标。然而，计算得到的gSUVmean |LI|在将TLE患者与对照受试者区分开来方面似乎并不特别有效。对更多患者进行的进一步研究应调查将gSUVmean与其他诊断预测指标相结合的其他机器学习技术。
