WHOLE-BODY SMALL-ANIMAL PHOTOACOUSTIC-ULTRASONIC COMPUTED TOMOGRAPHY

小动物全身光声超声计算机断层扫描

• 批准号: 8651915
• 负责人: Mark A Anastasio
• 金额: $ 57.57万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-05-01 至 2017-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8651915
• 关键词: Acoustics; Address; Algorithms; Animal Model; Animals; Biological; Biomedical Research; Brain; Complement; Contrast Media; Data; Detection; Development; Diffusion; Disease; Functional Imaging; Gases; Hemoglobin; Heterogeneity; Hybrids; Image; Ionizing radiation; Lasers; Life; Light; Magnetic Resonance Imaging; Measures; Methodology; Methods; Modeling; Molecular Probes; Monitor; Morphologic artifacts; Motion; Myocardial Infarction; Optics; Oxygen; Performance; Phase; Physiological; Play; Polycystic Kidney Diseases; Positron; Preclinical Drug Evaluation; Process; Property; Recovery; Resolution; Respiration; Role; Scheme; Small Animal Imaging Systems; Solutions; Speed; System; Techniques; Technology; Testing; Thick; Tissues; Ultrasonics; Ultrasonography; X-Ray Computed Tomography; absorption; attenuation; base; bone; data acquisition; density; design; diffuse optical tomography; electron tomography; heart motion; human disease; image reconstruction; imaging modality; improved; in vivo; magnetic field; molecular imaging; novel; pre-clinical; public health relevance; research study; soft tissue; sound; tissue phantom; tomography; tool; transmission process; tumor; whole body imaging

DESCRIPTION (provided by applicant): The objective of this R01 application is to develop an integrated small-animal whole-body photoacoustic- ultrasonic computed tomography system and the associated image reconstruction algorithms for simultaneous high-resolution anatomical and functional imaging with motion tracking. Due to the widespread use of animal models for human disease studies, small-animal whole-body imaging plays an increasingly important role in biomedical research. While much effort has been invested in the development of small-animal imaging systems, each of the available methods possesses significant limitations. Photoacoustic computed tomography (PACT) has recently been recognized as a promising tool for small- animal whole-body imaging. Utilizing the photoacoustic effect, PACT can image intact biological tissues with rich optical absorption contrast at high spatial resolution at tissue depth well beyond the optical diffusion limit (~1 mm). Since optical absorption is sensitive to physiological parameters such as the total concentration and oxygen saturation of hemoglobin, PACT can provide both anatomical and functional imaging. With the aid of functionalized contrast agents (molecular probes), PACT can also permit molecular imaging. Most PACT systems implemented to date assume that the to-be-imaged object possesses uniform acoustic properties. This assumption is strongly violated in whole-body imaging of small animals due to the presence of either thick bones or gas pockets, which possess speed-of-sound and mass density values greatly different from those of the surrounding soft tissues. In addition, the existing PACT systems suffer from significant motion artifacts. Accordingly, there remains an important need for the development of improved small-animal PACT systems and associated image reconstruction methodologies. The proposed integration of PACT and ultrasonic computed tomography (USCT) with motion tracking will bring unique advantages and allow us to overcome the two challenges mentioned above. First, the acoustic property distributions reconstructed by use of USCT will be employed to inform the PACT image reconstruction algorithms and hence improve the whole-body image quality. The ultrasonic contrasts will also complement optical contrasts from PACT for accurate multi-faceted disease assessment. Second, to minimize motion artifacts, respiration and cardiac motions will be monitored during data acquisition for retrospective gating. Therefore, the synergistic fusion of USCT and PACT will provide automatically co-registered anatomical and functional contrasts for comprehensive imaging without using ionizing radiation or exogenous contrast agents. The specific aims of this project are as follows: (1) Develop an integrated whole-body photoacoustic- ultrasonic computed tomography system. (2) Develop image reconstruction algorithms for use with the dual- modality imaging system. (3) Develop retrospectively respiration-gated tomography that minimizes motion artifacts. (4) Test the imaging systems with tissue phantoms and living animals.

描述（由申请人提供）：本R 01申请的目的是开发一种集成的小动物全身光声-超声计算机断层扫描系统和相关的图像重建算法，用于同时进行高分辨率解剖和功能成像以及运动跟踪。 由于动物模型在人类疾病研究中的广泛应用，小动物全身成像在生物医学研究中发挥着越来越重要的作用。虽然在小动物成像系统的开发上已经投入了大量的努力，但是每种可用的方法都具有显著的局限性。光声计算机断层扫描（PACT）最近被认为是一种有前途的工具，小动物全身成像。利用光声效应，PACT可以在远超过光学扩散极限（~1 mm）的组织深度以高空间分辨率对具有丰富光学吸收对比度的完整生物组织进行成像。由于光吸收对血红蛋白的总浓度和氧饱和度等生理参数敏感，因此PACT可以提供解剖学和功能成像。借助功能化造影剂（分子探针），PACT还可以进行分子成像。 迄今为止，大多数PACT系统都假设要成像的对象具有均匀的声学特性。这种假设在小动物的全身成像中被强烈违反，因为存在厚骨或气穴，其具有与周围软组织的声速和质量密度值大不相同的声速和质量密度值。另外，现有的PACT系统遭受显著的运动伪影。因此，仍然非常需要开发改进的小动物PACT系统和相关的图像重建方法。 PACT和超声计算机断层扫描（USCT）与运动跟踪的拟议集成将带来独特的优势，使我们能够克服上述两个挑战。首先，通过使用USCT重建的声学特性分布将被用来通知PACT图像重建算法，从而提高全身图像质量。超声造影还将补充PACT的光学造影，以进行准确的多方面疾病评估。其次，为了尽量减少运动伪影，将在数据采集期间监测呼吸和心脏运动，以进行回顾性门控。因此，USCT和PACT的协同融合将提供自动共配准的解剖和功能对比，用于全面成像，而无需使用电离辐射或外源性造影剂。 本课题的具体目标如下：（1）研制一体化全身光声-超声计算机断层成像系统。(2)开发用于双模态成像系统的图像重建算法。(3)开发回顾性呼吸门控断层扫描，最大限度地减少运动伪影。(4)用组织模型和活体动物测试成像系统。