UAB Epilepsy Center, Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, United States.
Epilepsy Res. 2013 Sep;106(1-2):146-54. doi: 10.1016/j.eplepsyres.2013.05.009. Epub 2013 Aug 3.
Asymmetry of hippocampal internal architecture (HIA) has been reported to be a frequent imaging finding in epilepsy patients with temporal lobe epilepsy (TLE) who exhibit other signs of hippocampal sclerosis. HIA asymmetry may also be an independent predictor of the side of seizure onset in patients with otherwise normal MRI scans. The study of HIA asymmetry and its relationship to the laterality of TLE would benefit from a reliable method of assessing the clarity of HIA in MRI scans. We propose a visual scoring system that rates HIA clarity from 1 (imperceptible) to 4 (excellent) and report the inter-rater reliability (IRR) of this system.
In the initial preliminary phase of this study we examined IRR using a kappa statistic (κ) among a mixed group of expert and non-expert reviewers using only a brief description of the scoring system to score single images from a series of patients. In the second phase we explored the effect of training on the use of our HIA scoring system by assessing IRR among neuroimaging experts before and after a brief interactive training session. In this phase, multiple slices from each patient were scored. Separate κ values and intraclass correlation coefficients (ICC) were calculated from the scores given to each hippocampal image and from the asymmetry of scores between left and right for each slice. In the third phase the effect of training on non-expert reviewers was explored using a similar approach as with the expert reviewers.
In the preliminary phase of the study, HIA scoring of single images showed substantial agreement among expert reviewers (κHIA=0.65), fair agreement among non-expert reviewers (κHIA=0.27), and a fair to moderate degree of agreement among all the reviewers as a whole (κHIA=0.40). In the second phase, prior to training there was substantial agreement among expert reviewers in regard to the individual HIA scores (κHIA=0.62; ICCHIA=0.81) but only moderate agreement on the degree of asymmetry (κAsym=0.47; ICCAsym=0.71). Training improved agreement on the individual HIA scores (κHIA=0.58-0.72; ICCHIA=0.76-0.84) and on the degree of asymmetry (κAsym=0.61-0.67; ICCAsym=0.81-0.85). Among non-expert reviewers, scores improved from only a fair degree of agreement pre-training (κHIA=0.25, κAsym=0.25; ICCHIA=0.68, ICCAsym=0.66) to a moderate level of agreement after training (κHIA=0.54, κAsym=0.52; ICCHIA=0.78, ICCAsym=0.81).
The proposed HIA scoring system has a substantial degree of inter-rater reliability among experienced neuroimaging reviewers. Training improves the detection of asymmetries in HIA score in particular. Non-expert reviewers can employ the system with a moderate degree of reliability, and training has an even greater impact on the improvement of scoring reliability.
海马内部结构的不对称性（HIA）已被报道为颞叶癫痫（TLE）患者中常见的影像学发现，这些患者表现出海马硬化的其他迹象。HIA 不对称性也可能是磁共振成像（MRI）扫描正常的患者癫痫发作起始侧的独立预测因素。研究 HIA 不对称性及其与 TLE 侧别的关系将受益于一种可靠的方法来评估 MRI 扫描中海马的清晰度。我们提出了一种视觉评分系统，将 HIA 清晰度从 1（不可察觉）到 4（极好）进行评分，并报告该系统的组内一致性（IRR）。
在这项研究的初步初步阶段，我们使用 Kappa 统计（κ）在混合的专家和非专家评审员之间检查了 IRR，仅使用评分系统的简要描述来对一系列患者的单个图像进行评分。在第二阶段，我们通过评估简短的互动培训课程前后神经影像学专家使用我们的 HIA 评分系统的效果，探讨了培训对 HIA 评分系统的使用的影响。在这一阶段，对每位患者的多个切片进行了评分。从每个海马图像的评分中计算了单独的 κ 值和组内相关系数（ICC），以及从每个切片的左右得分之间的不对称性中计算了 κ 值和 ICC。在第三阶段，我们采用类似的方法探讨了培训对非专家评审员的影响。
在研究的初步阶段，单个图像的 HIA 评分显示专家评审员之间有很大的一致性（κHIA=0.65），非专家评审员之间有很好的一致性（κHIA=0.27），以及所有评审员之间的一致性程度中等（κHIA=0.40）。在第二阶段，在培训之前，专家评审员在单个 HIA 评分方面具有很大的一致性（κHIA=0.62；ICCHIA=0.81），但在不对称程度上只有中等程度的一致性（κAsym=0.47；ICCAsym=0.71）。培训提高了对个别 HIA 评分的一致性（κHIA=0.58-0.72；ICCHIA=0.76-0.84）和不对称程度的一致性（κAsym=0.61-0.67；ICCAsym=0.81-0.85）。在非专家评审员中，评分从培训前的一致性仅为中等水平（κHIA=0.25，κAsym=0.25；ICCHIA=0.68，ICCAsym=0.66）提高到培训后的一致性水平较高（κHIA=0.54，κAsym=0.52；ICCHIA=0.78，ICCAsym=0.81）。
所提出的 HIA 评分系统在经验丰富的神经影像学评审员之间具有很大的组内一致性。培训尤其提高了 HIA 评分不对称性的检测能力。非专家评审员可以使用该系统获得中等程度的可靠性，并且培训对提高评分可靠性具有更大的影响。
