Hakyemez Bahattin, Erdogan Cuneyt, Yildiz Harun, Ercan Ilker, Parlak Mufit
Department of Radiology, Uludag University School of Medicine, Bursa, Turkey.
Epilepsy Behav. 2005 Mar;6(2):250-6. doi: 10.1016/j.yebeh.2004.12.008.
The goals of this work were to measure the apparent diffusion coefficients (ADCs) for both hippocampus and amygdala of persons diagnosed with temporal lobe epilepsy (TLE) and unilateral hippocampus pathology on magnetic resonance imaging and to evaluate the sensitivity of diffusion-weighted (DW) images in determination of the lateralization of the epileptogenic focus.
Thirteen cases with a TLE diagnosis and 21 healthy subjects were evaluated. Fluid-attenuated inversion recovery and T2W images of TLE cases revealed hippocampal volume loss and signal intensity changes. DW images were obtained by spin-echo echo-planar sequences vertical to the hippocampal axis. Qualitative and quantitative ADCs for left and right hippocampus and the amygdala of the controls and the patients were determined. Hippocampal ADCs were obtained independently at the head, body, and tail levels of the hippocampus. Statistical evaluation was conducted with Kruskal-Wallis and Mann-Whitney U tests. Predictive cutoff levels of hippocampal ADCs for identifying pathologic areas were established through receiver operating characteristic (ROC) curve analysis.
On conventional images, 5 of 13 cases had right hippocampal pathology, and 8 of 13 cases had left hippocampal pathology. There were no bilateral hippocampal changes in signal intensity and no cases with bilateral atrophy. The amygdala was normal in all patients except one case of hyperintense signals. No statistical differences were found between the hippocampal and amygdaloid ADCs of the control subjects (P > 0.05). However, there was a significant difference between the ADCs for the side with hippocampal pathology and the ADCs for the contralateral side, and the control group (P < 0.001). No statistical difference was detected for the amygdala (P > 0.05). Hippocampal and amygdaloid ADCs of the contralateral lesion and the values of the control group were not statistically significantly different (P > 0.05). ROC curve analysis indicated 136 as the best cutoff level for hippocampal pathology.
DW trace images are insensitive in lateralization of hippocampal pathology; however, lateralization can be achieved through ADC measurements of the hippocampus. An increase in ADC on the affected side should be considered as indicating pathology. On the other hand, amygdaloid ADC values remain inaccurate.
本研究旨在测量经磁共振成像诊断为颞叶癫痫（TLE）且存在单侧海马病变患者的海马和杏仁核的表观扩散系数（ADC），并评估扩散加权（DW）图像在确定致痫灶侧别方面的敏感性。
对13例TLE患者和21名健康受试者进行评估。TLE患者的液体衰减反转恢复序列和T2加权图像显示出海马体积缩小和信号强度变化。通过垂直于海马轴的自旋回波平面回波序列获取DW图像。测定对照组和患者左右海马及杏仁核的定性和定量ADC。海马ADC在海马的头部、体部和尾部水平独立获取。采用Kruskal-Wallis检验和Mann-Whitney U检验进行统计学评估。通过受试者操作特征（ROC）曲线分析确定用于识别病变区域的海马ADC预测临界值。
在常规图像上，13例患者中有5例右侧海马病变，8例左侧海马病变。信号强度无双侧海马改变，也无双侧萎缩病例。除1例信号增强外，所有患者的杏仁核均正常。对照组的海马和杏仁核ADC之间未发现统计学差异（P>0.05）。然而，海马病变侧的ADC与对侧及对照组的ADC之间存在显著差异（P<0.001）。杏仁核未检测到统计学差异（P>0.05）。对侧病变的海马和杏仁核ADC与对照组的值无统计学显著差异（P>0.05）。ROC曲线分析表明136为海马病变的最佳临界值。
DW追踪图像在海马病变侧别判断上不敏感；然而，通过测量海马的ADC可实现侧别判断。患侧ADC升高应被视为提示病变。另一方面，杏仁核ADC值仍不准确。
