Methods for modeling and predicting mechanical deformations of the breast under external perturbations
Methods for modeling and predicting mechanical deformations of the breast under external perturbations
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DOI：
10.1016/s1361-8415(01)00053-6
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发表时间：
2002-03-01
影响因子：
10.9
通讯作者：
Schnall, MD
中科院分区：
文献类型：
--
作者：
Azar, FS;Metaxas, DN;Schnall, MD
目前，高场（1.5 T）超导MR成像不允许在针乳房手术期间进行实时引导。目前的程序只允许医生在插入针头之前近似计算压缩患者乳房中癌性肿瘤的位置和程度。然后，在活检期间移除的组织样本实际上属于感兴趣的病变可能变得相对不确定。提出了一种基于乳腺可变形有限元模型的指导临床乳腺活检的新方法。该模型的几何结构是从MR数据构建的，其机械性能使用非线性材料模型建模。这种方法允许在手术前对乳房进行无或轻度压迫成像，然后压迫乳房并使用有限元模型来预测手术期间肿瘤的位置。对含有硬夹杂物的硅体模进行未压缩成像，然后压缩。使用定制编写的软件以及商业FEM模拟包构建和压缩体模模型。记录了真实的体模和两个压缩模型中夹杂物角部的位移。患者的乳房在未压缩然后压缩的情况下成像。构建未压缩乳房的可变形模型，然后压缩。在真实的和模拟的乳房中记录囊肿和贴在乳房表面的两片维生素E药丸的位移。整个过程持续了不到半个小时，使其在临床上有用，结果表明，它是可以创建一个基于有限元与非线性材料属性的乳房变形模型，能够建模和预测乳房变形在临床上有用的时间量。(C)2002 Elsevier Science BY，保留所有权利。
Currently, high field (1.5 T) superconducting MR imaging does not allow live guidance during needle breast procedures. The current procedure allows the physician only to calculate approximately the location and extent of a cancerous tumor in the compressed patient breast before inserting the needle. It can then become relatively uncertain that the tissue specimen removed during the biopsy actually belongs to the lesion of interest. A new method for guiding clinical breast biopsy is presented, based on a deformable finite element model of the breast. The geometry of the model is constructed from MR data, and its mechanical proper-ties are modeled using a non-linear material model. This method allows imaging the breast without or with mild compression before the procedure, then compressing the breast and using the finite element model to predict the tumor's position during the procedure. A silicon phantom containing a stiff inclusion was imaged uncompressed then compressed. A model of the phantom was constructed and compressed using custom-written software, and also using a commercial FEM simulation package. The displacement of the inclusion's corners was recorded both in the real phantom and in the two compressed models. A patient's breast was imaged uncompressed then compressed. A deformable model of the uncompressed breast was constructed, then compressed. The displacement of a cyst and of two vitamin E pills taped to the surface of the breast were recorded both in the real and in the modeled breast. The entire procedure lasted less than a half-hour, making it clinically useful, The results show that it is possible to create a deformable model of the breast based on finite elements with non-linear material properties, capable of modeling and predicting breast deformations in a clinically useful amount of time. (C) 2002 Elsevier Science BY, All rights reserved.