Acoustic Modeling of skull bone for improved transcranial MR-guided focused ultrasound therapy

颅骨声学建模用于改进经颅 MR 引导聚焦超声治疗

• 批准号: 10752399
• 负责人: Sam Clinard
• 金额: $ 4.21万
• 依托单位: UNIVERSITY OF UTAH
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-20 至 2025-07-19
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10752399
• 关键词: Ablation; Acoustics; Affect; Algorithms; Bathing; Blood - brain barrier anatomy; Cell Nucleus; Cephalic; Characteristics; Clinical; Clinical Data; Clinical Treatment; Compensation; Complex; Computed Tomography Scanners; Data; Dependence; Devices; Disease; Drug Delivery Systems; Eligibility Determination; Equation; Essential Tremor; FDA approved; Focused Ultrasound; Focused Ultrasound Therapy; Foundations; Future; Goals; Heating; High Resolution Computed Tomography; Human; Hybrids; Individual; Magnetic Resonance; Magnetic Resonance Imaging; Maps; Measurement; Measures; Mechanics; Mentors; Methods; Modality; Modeling; Monitor; Morbidity - disease rate; Neurology; Patients; Phase; Positioning Attribute; Procedures; Property; Research; Research Training; Safety; Sampling; Scanning; Speed; Stimulus; System; Temperature; Thalamic structure; Therapeutic; Thermal Ablation Therapy; Thermometry; Tissues; Water; Work; X-Ray Computed Tomography; attenuation; bone; cost; cranium; experience; experimental study; improved; individualized medicine; mortality; nervous system disorder; neuroregulation; novel; pressure; simulation; sound; transmission process; treatment duration; ultrasound

Project Summary/Abstract (Limit 30 lines) This proposal aims to improve the patient-specific Computed Tomography (CT)-derived modeling of transcranial focused ultrasound by comparing acoustic and thermal simulations to hydrophone scans of excised skull flaps and clinical magnetic resonance thermometry (MRTI) from Essential Tremor (ET) thalamotomy treatments. Magnetic resonance-guided transcranial focused ultrasound (tMRgFUS) is a non- invasive therapeutic modality used to treat a wide variety of neurological disorders. tMRgFUS relies on tightly focusing the ultrasound beam through the inhomogeneous human skull. A fundamental challenge is accurately determining the acoustic properties of the skull to phase-compensate for the inhomogeneities. Furthermore, acoustic parameters such as speed of sound c and attenuation α may change with increased temperature, causing further defocusing. Inaccurate acoustic parameters can result in off-target heating, longer treatment times, and failed treatments. This project will improve the focusing of ultrasound through the human skull by accurately determining individual skull acoustic parameters. The Hybrid Angular Spectrum (HAS) beam simulation method and the Pennes bioheat equation can simulate pressure fields and thermal rises by mapping acoustic and thermal parameters to CT Hounsfield Units. The results of these simulations may be compared to experimental data to determine the accuracy of tFUS acoustic and thermal modeling. Applying this method in reverse, a surrogate optimization algorithm, which excels at black-box expensive optimization problems, will be used to iteratively adjust simulation parameters to fit experimental data using a cost function. Aim I will determine the relationship of the acoustic properties of bone to CT Hounsfield Units. An optimization algorithm will iteratively adjust the acoustic parameter mapping such that a cost function comparing simulated and measured transmitted acoustic pressures is minimized. The resulting optimal acoustic parameters accurately model transcranial acoustic transmission. Aim II will determine the cause of reduced treatment efficiency with high acoustic powers during tMRgFUS. An optimization algorithm will iteratively adjust the acoustic and thermal parameters to minimize a cost function comparing simulation to MRTI data from clinical ET Thalamotomy patients. This work will improve acoustic modeling through the human skull, which is the first step in improving transcranial focused ultrasound therapy. According to the Focused Ultrasound Foundation, tMRgFUS could be applied to at least 34 neurological disorders. Thus, this work could have a magnified effect, significantly reducing morbidity and mortality across the field of neurology.

项目摘要/摘要（限 30 行） 该提案旨在改进患者特异性计算机断层扫描 (CT) 衍生的模型 通过将声学和热模拟与水听器扫描进行比较来进行经颅聚焦超声 切除的颅骨瓣和特发性震颤 (ET) 的临床磁共振测温 (MRTI) 丘脑切除术治疗。磁共振引导经颅聚焦超声（tMRgFUS）是一种非 用于治疗多种神经系统疾病的侵入性治疗方式。 tMRgFUS 紧密依赖 通过不均匀的人类头骨聚焦超声波束。一个根本性的挑战是准确地 确定头骨的声学特性以对不均匀性进行相位补偿。此外， 声速 c 和衰减 α 等声学参数可能会随着温度的升高而变化， 造成进一步的散焦。不准确的声学参数可能导致加热偏离目标、治疗时间延长 次，治疗失败。 该项目将通过准确确定超声波通过人类头骨的聚焦效果 个体头骨声学参数。混合角谱（HAS）光束模拟方法和 Pennes 生物热方程可以通过映射声学和热学来模拟压力场和热升 CT 亨斯菲尔德单位的参数。这些模拟的结果可以与实验数据进行比较 确定 tFUS 声学和热建模的准确性。反向应用此方法，代理 优化算法擅长处理黑盒昂贵的优化问题，将用于迭代 使用成本函数调整模拟参数以适应实验数据。目标我将确定关系 骨骼的声学特性与 CT 亨斯菲尔德单位的关系。优化算法将迭代调整 声学参数映射，以便比较模拟和测量的传输声学的成本函数 压力被最小化。由此产生的最佳声学参数可以准确地模拟经颅声学 传播。目标 II 将确定高声功率处理效率降低的原因 tMRgFUS。优化算法将迭代调整声学和热学参数，以最小化 将模拟与临床 ET 丘脑切除术患者的 MRTI 数据进行成本函数比较。 这项工作将通过人类头骨改进声学建模，这是改进的第一步 经颅聚焦超声治疗。根据聚焦超声基金会的说法，tMRgFUS 可以 应用于至少 34 种神经系统疾病。因此，这项工作可能会产生显着的放大效应 降低整个神经病学领域的发病率和死亡率。