Abulnaga S Mazdak, Turk Esra Abaci, Bessmeltsev Mikhail, Grant P Ellen, Solomon Justin, Golland Polina
Computer Science and Artificial Intelligence Lab, MIT, Cambridge, MA, USA.
Fetal-Neonatal Neuroimaging and Developmental Science Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
Med Image Comput Comput Assist Interv. 2019 Oct;11767:39-47. doi: 10.1007/978-3-030-32251-9_5. Epub 2019 Oct 10.
We present a volumetric mesh-based algorithm for flattening the placenta to a canonical template to enable effective visualization of local anatomy and function. Monitoring placental function promises to support pregnancy assessment and to improve care outcomes. We aim to alleviate visualization and interpretation challenges presented by the shape of the placenta when it is attached to the curved uterine wall. To do so, we flatten the volumetric mesh that captures placental shape to resemble the well-studied shape. We formulate our method as a map from the shape to a flattened template that minimizes the symmetric Dirichlet energy to control distortion throughout the volume. Local injectivity is enforced via constrained line search during gradient descent. We evaluate the proposed method on 28 placenta shapes extracted from MRI images in a clinical study of placental function. We achieve sub-voxel accuracy in mapping the boundary of the placenta to the template while successfully controlling distortion throughout the volume. We illustrate how the resulting mapping of the placenta enhances visualization of placental anatomy and function. Our implementation is freely available at https://github.com/mabulnaga/placenta-flattening.
我们提出了一种基于体网格的算法，用于将胎盘展平为标准模板，以实现对局部解剖结构和功能的有效可视化。监测胎盘功能有望支持孕期评估并改善护理结果。我们旨在缓解胎盘附着于弯曲子宫壁时其形状所带来的可视化和解读挑战。为此，我们将捕捉胎盘形状的体网格展平，使其类似于经过充分研究的形状。我们将我们的方法表述为从该形状到展平模板的映射，该映射使对称狄利克雷能量最小化，以控制整个体积内的变形。在梯度下降过程中，通过约束线搜索来强制局部单射性。在一项胎盘功能的临床研究中，我们对从MRI图像中提取的28个胎盘形状评估了所提出的方法。我们在将胎盘边界映射到模板时实现了亚体素精度，同时成功地控制了整个体积内的变形。我们展示了由此产生的胎盘映射如何增强对胎盘解剖结构和功能的可视化。我们的实现可在https://github.com/mabulnaga/placenta - flattening上免费获取。
