Development of Thermoacoustic Tomography Brain Imaging

描述（由申请人提供）：热声断层扫描（达特）是一种迅速兴起的超声介导混合成像模式，有望对诊断成像产生重大影响。达特在单一混合模式中结合了高超声分辨率和强微波对比度。人脑成像代表了一种重要的成像应用，其可以通过达特方法的发展而极大地受益。现有的高分辨率人脑成像模式，例如X射线计算机断层扫描（CT）和磁共振成像（MRI）是昂贵的，并且采用体积庞大且通常非便携式的成像设备。此外，X射线CT使用电离辐射，对于需要长时间监测脑部疾病或损伤的患者来说是不安全的。或者，超声检查是一种已建立的便携式儿科脑成像模式，但其图像质量严重下降时，关闭后的<$门，因此是不是有效的成像成人。达特脑成像方法的发展将绕过这些限制，并导致一个强大的新的脑成像模式，将填补一个重要的空白留下的可用技术。达特脑成像的主要技术挑战是补偿由颅骨引入达特测量数据的失真。该提案的主要目标是通过开发强大的图像重建方法，使达特脑成像成为一种实用，有用和高效的脑成像方式，该方法可以解释颅骨引起的信号失真和其他物理因素。通过使用从先前采集的辅助图像数据或从达特测量数据本身获得的关于颅骨形态和组成的信息，我们将开发和研究用于达特的稳健成像模型，该模型考虑颅骨引起的波前像差和与测量过程相关的其他物理因素的影响。我们将开发重建算法，用于从不完整的数据集获得准确的图像，这些数据集对应于临床上有用的测量配置。所开发的方法将在计算机模拟和实验研究中进行系统评估。还将进行人类达特脑成像的首次体内研究。该项目的具体目标是：（1）开发成像方法，纳入头骨引起的相位畸变的影响;（2）开发用于实际脑成像扫描配置的图像重建算法;（3）验证计算机模拟研究中达特脑成像的重建方法;以及（4）评估体模和体内研究中的图像质量。 公共卫生相关性：热声断层成像脑成像的发展将产生一个强大的和有效的新模式，监测脑状况，如中风，肿瘤和脑损伤。其相对于现有高分辨率人脑成像模式的具体优势包括：1）相对低成本，2）允许在床边或手术室中进行近实时成像研究的便携性，3）使用非电离辐射，以及4）测量与现有方法所揭示的信息互补的结构和功能脑信息。

DESCRIPTION (provided by applicant): Thermo acoustic tomography (TAT) is a rapidly emerging ultrasound-mediated hybrid imaging modality that promises to have a major impact on diagnostic imaging. TAT combines high ultrasonic resolution and strong microwave contrast in a single hybrid modality. Human brain imaging represents an important imaging application that can benefit tremendously by the development of TAT methods. Existing high-resolution human brain imaging modalities such as X-ray computed tomography (CT) and magnetic resonance imaging (MRI) are expensive and employ bulky and generally non-portable imaging equipment. Moreover, X-ray CT employs ionizing radiation and is unsafe for patients who need long time monitoring of brain diseases or injuries. Alternatively, ultrasonography is an established portable pediatric brain imaging modality, but its image quality degrades severely when employed after the closure of the fontanels and therefore is not effective for imaging adults. The development of TAT brain imaging methods would circumvent these limitations and result a powerful new brain imaging modality that would fill an important void left by the available techniques. The major technical challenge in TAT brain imaging is to compensate for the distortion introduced into the TAT measurement data by the skull. The broad objective of this proposal is to make TAT brain imaging a practical, useful, and highly effective brain imaging modality by developing robust image reconstruction methods that can account for skull-induced signal distortion and other physical factors. By use of information regarding the skull morphology and composition obtained from previously acquired adjunct image data, or alternatively from the TAT measurement data themselves, we will develop and investigate robust imaging models for TAT that account for the effects of skull-induced wave front aberrations and other physical factors related to the measurement process. We will develop reconstruction algorithms for obtaining accurate images from incomplete data sets that correspond to clinically useful measurement configurations. The developed methods will be systematically evaluated in computer-simulation and experimental studies. The first in vivo study of human TAT brain imaging will also be conducted. The specific aims of the project are: (1) To develop imaging methodologies that incorporate the effects of skull-induced phase aberrations; (2) To develop image reconstruction algorithms for practical brain imaging scanning configurations; (3) To validate the reconstruction methods for TAT brain imaging in computer-simulation studies; and (4) To assess image quality in phantom and in-vivo studies. PUBLIC HEALTH RELEVANCE: The development of thermo acoustic tomography brain imaging will yield a powerful and effective new modality for monitoring brain conditions such as strokes, tumors, and brain injuries. Its specific advantages over existing high-resolution human brain imaging modalities include 1) relatively low-cost, 2) portability that would permit near real-time imaging studies at bedside or in operating rooms, 3) use of non-ionizing radiation, and 4) measurement of structural and functional brain information that is complementary to that revealed by existing methods.