Brain Ultrasound Computed Tomography Through the Intact Skull

描述(申请人提供)：长期以来，颅骨一直是产生超声脑部图像的障碍，导致扭曲和衰减，限制了超声的诊断作用，主要是通过经颅多普勒检测血液流动，应用于骨骼的薄薄区域。在过去的十年里，我们一直在开发通过最大化能量传递和最小化骨骼变形来克服这些限制的基本技术。这项工作最终形成了一种新技术，该技术具有在临床上产生清晰和准确图像的潜力。这项技术通过定制的设备实现，使用环绕头骨的超声波喷射器的反馈来纠正头骨变形。优化的波束将用于产生超声计算机断层扫描(UCT)图像，该图像将显示颅骨和大脑的全横断面，提供类似于CT或MRI的用户定位。我们将使用一种新的重建方法，它在理论上与基于射频的衍射层析成像有相似之处，但它进一步利用了超声波的优越能力来定制成像波束形状。与依赖短脉冲分辨率的传统超声不同，该方法将使用一个或多个单一超声频率来创建图像，从而允许多周期(随后要强得多)的成像信号。这项工作的总体目标是生产一种便携式、非电离的脑损伤和疾病诊断工具，可用于偏远地区、患者床边，或用于病情无法使用MRI或CT的患者。我们计划在授权期结束前将这项技术开发成一种可用于临床测试的设备。磁共振成像将被用作评估该设备成功与否的基准，量化目标旨在检测和跟踪毫米分辨率的解剖特征和异常。该项目可以为大脑疾病和损伤的早期诊断提供广泛的好处，并为重复监测已知的现有疾病提供一种新的工具。 与公共健康相关：头骨严重限制了超声波在大脑中的使用。然而，我们一直在开发技术来克服这些限制，现在我们将结合这些技术来产生目前只能使用大型和高成本设备(如MRI和CT)才能产生的脑图像。到拟议的项目结束时，我们计划完成并测试设备，准备在诊所进行测试。

DESCRIPTION (provided by applicant): The skull has long served as a barrier to producing ultrasound brain images, causing distortion and attenuation that have limited ultrasound's diagnostic role primarily to detecting blood flow by transcranial Doppler applied to a thin region of the bone. Over the past decade, we have been developing basic techniques to overcome these limits by maximizing energy transfer and minimizing distortion through the bone. This work has culminated in a new technique that holds the potential for producing clear and accurate images in the clinic. Implemented through a custom device, the technique will correct for skull distortion using feedback from an ultrasound applicator that encircles the skull. Optimized beams will be used to produce ultrasound computed tomography (UCT) images, which will display full cross-sections of both the skull and brain, providing user orientation similar to that of CT or MRI. We will use a novel reconstruction method, which has theoretical parallels with radio-frequency-based diffraction tomography, but which further utilizes ultrasound's superior ability to customize the imaging beamshape. Unlike traditional ultrasound, which relies on short pulses for resolution, the method will use one or more single ultrasound frequencies to create an image, permitting a multi-cycle (and subsequently much stronger) imaging signal. The overall goal of the work is produce a portable, non-ionizing diagnostic tool for brain injury and disorders that could be used in remote locations, patient bedside, or for patients whose condition precludes the use of MRI or CT. We plan to develop this technique into a device ready for clinical testing by the end of the grant period. MRI will be used as a benchmark to evaluate the device's success, with quantitative goals aiming at the detection and tracking of millimeter-resolution anatomical features and abnormalities. The project could provide extensive benefits toward early diagnosis of brain disorders and injury as well as offer a new tool for repeated monitoring of known existing conditions. PUBLIC HEALTH RELEVANCE: The skull has severely limited ultrasound's use in the brain. However, we have been developing techniques to overcome these limits, which we will now combine to produce brain images presently only possible using large and high-cost devices, such as MRI and CT. By the end of the proposed project we plan to have a completed and tested device, ready for testing in the clinic.