Data acquisition and analyses for the development of diagnostic ultrasound safety

用于诊断超声安全性发展的数据采集和分析

• 批准号: 8176471
• 负责人: CHARLES Clair CHURCH
• 金额: $ 17.64万
• 依托单位: UNIVERSITY OF MISSISSIPPI
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-07-01 至 2013-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8176471
• 关键词: 3-Dimensional; Acoustics; Address; Air; Biological; Blood; Blood Vessels; Blood capillaries; Classical Mechanics; Clinic; Clinical; Contrast Media; Data; Data Analyses; Development; Devices; Diagnostic; Diagnostic Procedure; Dose; Drug Formulations; Effectiveness; Ensure; Equilibrium; Family; Fatty acid glycerol esters; Frequencies; Future; Future Generations; Gases; Generations; Goals; Heating; Image; Imaging Techniques; International; Ionizing radiation; Kidney; Length; Liver; Mechanics; Medical; Methods; Metric; Modeling; Muscle; Outcome; Physicians; Physiologic pulse; Positioning Attribute; Probability; Property; Radiation; Research; Research Project Grants; Safety; Scheme; Series; Skin; Sulfur Hexafluoride; Techniques; Temperature; Theoretical Studies; Therapeutic procedure; Time; Tissues; Tube; Ultrasonography; United States National Institutes of Health; Water; Weight; Work; absorption; base; capillary; computer studies; data acquisition; design; evidence base; flexibility; imaging modality; indexing; injured; interest; novel strategies; patient safety; research study; viscoelasticity

DESCRIPTION (provided by applicant): When acoustic waves, e.g., pulses of diagnostic ultrasound, propagate through a medium, e.g., tissue, absorption and scattering of the wave induce a net force, called a "radiation force", in the medium. This force displaces the medium from its equilibrium position. A relatively new family of imaging methods makes use of this effect to obtain qualitatively new types of diagnostic information. Termed Acoustic Radiation Force Impulse imaging, or ARFI, the radiation force produced in tissue by long, relatively high-amplitude pulses produces tissue displacements that are quite different from those produced by standard imaging, and the magnitude and temporal dynamics of the displacements provide information on the viscoelastic properties of the tissue. These techniques allow the clinician to distinguish healthy from damaged or diseased tissue. However, ARFI employs ultrasound pulses that are much longer, and often of higher amplitude, than those currently used for ultrasound imaging, and there is concern that because these longer pulses do not adhere to the fundamental assumptions underlying the current ultrasound safety indices, i.e., the thermal index (TI) and the mechanical index (MI), ARFI may be unsafe in certain circumstances. There is a growing need for national and international standards to ensure patient safety during ARFI imaging. At present, there are few objective data upon which to base these needed standards. The goal of the proposed research project is to provide for the creation of encompassing yet flexible safety standards by conducting several series of computational and experimental studies specifically designed to acquire the data needed to develop such standards. The Specific Aims of the proposed project are: 1) determine the threshold for inertial cavitation for spherical bubbles under all relevant conditions (6 conditions have been identified, e.g., threshold criteria appropriate for mechanical in addition to thermal damage, use of longer acoustic pulse durations and dual-frequency exposures, etc.), 2) determine the temperature-time profiles and thermal doses (TD) for ARFI-type pulses (development of safety standards based on use of the thermal dose, rather than the maximum steady-state temperature rise as is currently done, is fundamental to this proposal), and 3) quantify the thermal dose in terms of absorbed energy rather than time and develop this new formulation into a universally applicable ultrasound dose metric (first following a development path like that successfully employed with ionizing radiation, then investigating a newly formulated concept, the thermal action function, which is analogous to the action integral of classical mechanics). The first two aims are relatively focused in that they will provide data to support the use of new imaging modalities. The third aim focuses on developing an exposure metric to guide selection of optimal parameters for both diagnostic and therapeutic procedures using clinical ultrasound. PUBLIC HEALTH RELEVANCE: The overall goal of this project is to ensure the safety of diagnostic ultrasound by accomplishing two major objectives: 1) Provide both theoretical and experimental data upon which national and international safety standards for Acoustic Radiation Force Impulse imaging (ARFI) imaging methods can be based, and 2) Develop a new mathematical formula that will allow physicians to determine optimal ultrasound exposure settings for different diagnostic purposes ARFI is a relatively new family of imaging methods in diagnostic ultrasound. These techniques allow the physician to distinguish healthy tissue from tissue that is diseased or injured in some way. However, ARFI may employ ultrasound pulses that are much longer, and often of higher amplitude, than those currently used for ultrasound imaging. Because of this, there is concern that introduction of these techniques into the clinic may jeopardize the stellar safety record that diagnostic ultrasound has maintained over 5 decades of medical practice. This project is designed to provide both theoretical and experimental data upon which appropriate national and international safety standards can be based to help ensure that ultrasound preserves its unique position as the safest of all the imaging methods available to the physician. The second objective of this work is to develop an entirely new mathematical formula that will allow the physician to determine the very best ultrasound exposure settings to obtain the necessary diagnostic information by using the very lowest total energy. The results of this project will advance understanding of medical ultrasound methods and help ensure the safety of diagnostic ultrasound both now and well into the future.

描述（由申请人提供）：当声波（例如，诊断超声波的脉冲）通过培养基传播时，例如，组织，组织，吸收和散射在介质中诱导净力，称为“辐射力”。这种力使介质从其平衡位置置换。相对较新的成像方法系列可以利用这种效果来获得定性的诊断信息。被称为声辐射力脉冲成像或ARFI，由长，相对较高的振幅脉冲在组织中产生的辐射力产生的组织位移与标准成像产生的辐射脉冲与标准成像产生的辐射脉冲以及组织特性的位移的大小和时间动力学完全不同。这些技术使临床医生能够将健康与受损或患病的组织区分开。但是，ARFI采用的超声波脉冲比当前用于超声成像的脉冲更长，并且通常具有更高的振幅，并且令人担忧的是，因为这些较长的脉冲并不符合当前超声安全指数的基本假设，即热指数（即热索引（TI）（TI）和某些机械index（MI）（mi），Arfi infe infe inf afi。国家和国际标准的需求日益增长，以确保ARFI成像期间的患者安全。目前，很少有客观数据可以基于这些所需标准。拟议的研究项目的目的是通过进行一些专门设计的计算和实验研究来创建包含但灵活的安全标准，以获取制定此类标准所需的数据。 The Specific Aims of the proposed project are: 1) determine the threshold for inertial cavitation for spherical bubbles under all relevant conditions (6 conditions have been identified, e.g., threshold criteria appropriate for mechanical in addition to thermal damage, use of longer acoustic pulse durations and dual-frequency exposures, etc.), 2) determine the temperature-time profiles and thermal doses (TD) for ARFI-type pulses (development of safety standards based on use of the thermal dose, rather than the maximum steady-state temperature rise as is currently done, is fundamental to this proposal), and 3) quantify the thermal dose in terms of absorbed energy rather than time and develop this new formulation into a universally applicable ultrasound dose metric (first following a development path like that successfully employed with ionizing radiation, then investigating a newly formulated concept, the thermal action function, which is analogous to the action古典力学的积分）。前两个目标相对重视，因为它们将提供数据以支持新成像方式的使用。第三个目标着重于开发暴露度量，以指导使用临床超声检查诊断和治疗程序的最佳参数的选择。 公共卫生相关性：该项目的总体目标是通过实现两个主要目标来确保诊断超声的安全：1）提供理论和实验数据，国家和国际声学辐射力脉冲成像（ARFI）成像方法（ARFI）成像的标准可以基于这些数据，并且可以基于实现新的数学习惯，以确定最佳的估计范围，以确定最佳的估计范围。诊断超声中的成像方法家族。这些技术使医生可以将健康组织与以某种方式患病或受伤的组织区分开。但是，与当前用于超声成像的脉冲相比，ARFI可以使用更长且幅度更高的超声脉冲。因此，人们担心将这些技术引入诊所可能会危害诊断超声已经维持超过5年的医疗实践的出色安全记录。该项目旨在提供理论和实验数据，在这些数据上，适当的国家和国际安全标准可以基于这些数据，以帮助确保超声将其独特的位置保存为医生可用的所有成像方法中最安全的地位。这项工作的第二个目标是开发一个全新的数学公式，该公式将允许医生确定最佳的超声暴露设置，以使用最低的总能量获得必要的诊断信息。该项目的结果将提高对医学超声方法的了解，并有助于确保诊断超声检查现在和未来的安全性。