Vargo Vincenzia S, Routzong Megan R, Moalli Pamela A, Rostaminia Ghazaleh, Abramowitch Steven D
University of Pittsburgh, Department of Bioengineering, Pittsburgh, Pennsylvania, United States.
University of Pittsburgh, Magee-Womens Research Institute, Department of Obstetrics, Gynecology & Reproductive Surgery, Pittsburgh, Pennsylvania, United States.
J Med Imaging (Bellingham). 2024 Jul;11(4):045001. doi: 10.1117/1.JMI.11.4.045001. Epub 2024 Aug 10.
The measures that traditionally describe the levator hiatus (LH) are straightforward and reliable; however, they were not specifically designed to capture significant differences. Statistical shape modeling (SSM) was used to quantify LH shape variation across reproductive-age women and identify novel variables associated with LH size and shape.
A retrospective study of pelvic MRIs from 19 nulliparous, 32 parous, and 12 pregnant women was performed. The LH was segmented in the plane of minimal LH dimensions. SSM was implemented. LH size was defined by the cross-sectional area, maximal transverse diameter, and anterior-posterior (A-P) diameter. Novel SSM-guided variables were defined by regions of greatest variation. Multivariate analysis of variance (MANOVA) evaluated group differences, and correlations determined relationships between size and shape variables.
Overall shape ( ), SSM mode 2 (oval to -shape, ), mode 3 (rounder to broader anterior shape, ), and maximal transverse diameter ( ) significantly differed between groups. Novel anterior and posterior transverse diameters were identified at 14% and 79% of the A-P length. Anterior transverse diameter and maximal transverse diameter were strongly correlated ( , ), while posterior transverse diameter and maximal transverse diameter were weakly correlated ( , ).
The traditional maximal transverse diameter generally corresponded with SSM findings but cannot describe anterior and posterior variation independently. The novel anterior and posterior transverse diameters represent both size and shape variation, can be easily calculated alongside traditional measures, and are more sensitive to subtle and local LH variation. Thus, they have a greater ability to serve as predictive and diagnostic parameters.
传统上描述提肌裂孔（LH）的测量方法简单可靠；然而，它们并非专门设计用于捕捉显著差异。统计形状建模（SSM）用于量化生育年龄女性LH形状的变化，并识别与LH大小和形状相关的新变量。
对19例未生育、32例已生育和12例孕妇的盆腔MRI进行回顾性研究。在LH最小尺寸平面上对LH进行分割。实施SSM。LH大小由横截面积、最大横径和前后径（A-P）定义。由最大变化区域定义新的SSM引导变量。多变量方差分析（MANOVA）评估组间差异，相关性确定大小和形状变量之间的关系。
总体形状（ ）、SSM模式2（椭圆形至 形， ）、模式3（前部形状更圆至更宽， ）和最大横径（ ）在各组之间存在显著差异。在A-P长度的14%和79%处确定了新的前后横径。前横径与最大横径高度相关（ ， ），而后横径与最大横径弱相关（ ， ）。
传统的最大横径一般与SSM结果相符，但不能独立描述前后变化。新的前后横径代表大小和形状变化，可与传统测量方法一起轻松计算，并且对LH的细微和局部变化更敏感。因此，它们作为预测和诊断参数的能力更强。
