BACKGROUND Sagittal craniosynostosis (SC) is associated with scaphocephaly, an elongated narrow head shape. Assessment of regional severity in the scaphocephalic head is limited by the use of serial CT imaging or complex computer programing. Three-dimensional measurements of cranial surface morphology provide a radiation-free alternative for assessing cranial shape. This study describes the creation of an Occipital Bulleting Index (OBI), a novel tool using surface morphology to assess the regional severity in patients with SC. METHODS Surface imaging from CT scans or 3D photographs of 360 individuals with sagittal craniosynostosis and 221 normocephalic individuals were compared to identify differences in morphology. Cartesian grids were created on each individual's surface mesh using equidistant axial and sagittal planes. Area under the curve (AUC) analyses were performed to identify trends in regional morphology and create measures capturing population differences. RESULTS The largest differences were located in the medial regions posteriorly. Using these population trends, a measure was created maximizing AUC. The Occipital Bullet index has an AUC of 0.72 with a sensitivity of 74% and a specificity of 61%. When the Frontal Bossing Index is applied in tandem, the two have a sensitivity of 94.7% and a specificity of 93.1%. Correlation between the two scores in individuals with SC was found to be negligible with an intraclass correlation coefficient of 0.018. Severity was found to be independent of age under 24 months, sex, and imaging modality. CONCLUSIONS This index creates a tool for differentiating control head shapes from those with sagittal craniosynostosis, and has the potential to allow for objective evaluation of the regional severity, outcomes of different surgical techniques, and tracking shape changes in individuals over time, without the need for radiation. .

中文翻译：

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矢状位颅缝早闭后形态学的新测量方法：枕叶子弹指数。

背景技术矢状颅缝早闭（SC）与舟状头畸形（一种细长的狭窄头部形状）相关。舟头区域严重程度的评估受到连续 CT 成像或复杂计算机编程的使用的限制。颅骨表面形态的三维测量为评估颅骨形状提供了无辐射的替代方案。本研究描述了枕叶弹跳指数 (OBI) 的创建，这是一种利用表面形态来评估 SC 患者区域严重程度的新工具。方法 对 360 名矢状颅缝早闭患者和 221 名正常头颅患者的 CT 扫描或 3D 照片的表面成像进行比较，以确定形态上的差异。使用等距的轴向平面和矢状平面在每个个体的表面网格上创建笛卡尔网格。进行曲线下面积 (AUC) 分析，以确定区域形态的趋势并创建捕获群体差异的度量。结果最大的差异位于后内侧区域。利用这些人口趋势，创建了一种最大化 AUC 的措施。枕叶子弹指数的 AUC 为 0.72，敏感性为 74%，特异性为 61%。当 Frontal Bossing Index 串联应用时，两者的敏感性为 94.7%，特异性为 93.1%。SC 个体的两个分数之间的相关性可以忽略不计，组内相关系数为 0.018。研究发现，严重程度与 24 个月以下的年龄、性别和成像方式无关。结论 该指数创建了一种区分控制头形状与矢状颅缝早闭的工具，并且有可能客观评估区域严重程度、不同手术技术的结果，并跟踪个体随时间的形状变化，而无需辐射。。