Berger M, Pillei M, Giotakis A, Mehrle A, Recheis W, Kral F, Kraxner M, Riechelmann H, Freysinger W
Department of Environmental, Process and Energy Engineering, MCI-The Entrepreneurial School, Innsbruck, Austria.
Department of Otorhinolaryngology-Head and Neck Surgery, Medical University of Innsbruck, Innsbruck, Austria.
Int J Comput Assist Radiol Surg. 2021 Apr;16(4):567-578. doi: 10.1007/s11548-021-02342-z. Epub 2021 Mar 24.
State-of-the-art medical examination techniques (e.g., rhinomanometry and endoscopy) do not always lead to satisfactory postoperative outcome. A fully automatized optimization tool based on patient computer tomography (CT) data to calculate local pressure gradient regions to reshape pathological nasal cavity geometry is proposed.
Five anonymous pre- and postoperative CT datasets with nasal septum deviations were used to simulate the airflow through the nasal cavity with lattice Boltzmann (LB) simulations. Pressure gradient regions were detected by a streamline analysis. After shape optimization, the volumetric difference between the two shapes of the nasal cavity yields the estimated resection volume.
At LB rhinomanometry boundary conditions (bilateral flow rate of 600 ml/s), the preliminary study shows a critical pressure gradient of -1.1 Pa/mm as optimization criterion. The maximum coronal airflow ΔA := cross-section ratio [Formula: see text] found close to the nostrils is 1.15. For the patients a pressure drop ratio ΔΠ := (pre-surgery - virtual surgery)/(pre-surgery - post-surgery) between nostril and nasopharynx of 1.25, 1.72, -1.85, 0.79 and 1.02 is calculated.
LB fluid mechanics optimization of the nasal cavity can yield results similar to surgery for air-flow cross section and pressure drop between nostril and nasopharynx. The optimization is numerically stable in all five cases of the presented study. A limitation of this study is that anatomical constraints (e.g. mucosa) have not been considered.
先进的医学检查技术（如鼻阻力测量法和内窥镜检查）并不总能带来令人满意的术后效果。本文提出一种基于患者计算机断层扫描（CT）数据的全自动优化工具，用于计算局部压力梯度区域，以重塑病理性鼻腔几何形状。
使用五个匿名的鼻中隔偏曲术前和术后CT数据集，通过格子玻尔兹曼（LB）模拟来模拟鼻腔内的气流。通过流线分析检测压力梯度区域。形状优化后，鼻腔两种形状之间的体积差异得出估计的切除体积。
在LB鼻阻力测量边界条件（双侧流速为600 ml/s）下，初步研究表明临界压力梯度为-1.1 Pa/mm作为优化标准。在鼻孔附近发现的最大冠状气流ΔA := 横截面比[公式：见原文]为1.15。对于患者，计算出鼻孔与鼻咽之间的压降比ΔΠ :=（术前 - 虚拟手术）/（术前 - 术后）分别为1.25、1.72、-1.85、0.79和1.02。
鼻腔的LB流体力学优化在气流横截面以及鼻孔与鼻咽之间的压降方面可产生与手术相似的结果。在所呈现研究的所有五个案例中，该优化在数值上是稳定的。本研究的一个局限性是未考虑解剖学限制（如黏膜）。
