Advanced Fetal Imaging

描述（由申请人提供）：胎儿时期是大脑发育和发育无与伦比的时期，可以说是决定未来认知潜力的最重要时期。因此，当胎儿大脑发育受损时，就像在包括先天性心脏病（CHD）在内的许多疾病中一样，子宫内就会出现异常，并导致终身认知障碍，即使有最佳的产后护理也无法纠正。这导致公共卫生迫切需要在子宫早期发现解剖和生理异常的方法，以便更好地向父母提供咨询，并更好地指导胎儿干预（手术或医学）的发展和优化，以预防或减轻这种长期后果。尽管胎儿核磁共振成像（胎儿核磁共振成像）能够发挥这一作用一直很乐观，但它仍然受到妊娠腹部独特解剖结构、胎儿体积小以及最重要的胎儿运动的严重限制。因此，胎儿脑核磁共振成像远远落后于产后脑成像。事实上，胎儿脑MR评估仍然主要局限于快速单次T2序列，其固有的脑对比度较差，光谱，扩散和灌注不可靠或不可能使用当前的方法。因此，胎儿MRI提供稳健和准确的结构和生理评估的潜力仍未实现。我们建议使用一种集成的方法来推进胎儿MRI，该方法解决了从硬件到脉冲序列设计的整个成像采集过程，目的如下：发展核磁共振硬件和解剖采集方法。我们建议开发第一个拟人化的胎儿MRI模体，以安全测试我们开发的可行性，并确保SAR的安全性。我们将为孕妇腹部建立首个128通道接收相控阵，方便图像加速和提高信噪比。我们将建立在新兴的平行传输（pTx）领域，并率先将其应用于胎儿成像，目标是仅刺激胎儿头部区域，以最小化SAR，实现进一步的加速，并为未来的运动导航提供目标。随着胎儿成像压缩感知（CS）技术的发展，图像采集将获得额外的速度。这些改进将使改进的解剖图像（TSE和MPRAGE）；目标2。发展生理获取方法。利用Aim 1的进展发展稳健的扩散、光谱和灌注成像；和Aim 3。转化为先天性心脏病胎儿脑MRI评估。我们将评估我们的能力或我们的进展，以更好地检测结构和生理异常的CHD与目前的胎儿MRI在相同的受试者和比较正常对照的先进方案。此外，我们将尝试检测胎儿干预后左心发育不全综合征（HLHS）的生理变化。总之，我们的目标是通过在胎儿MRI实验的采集端开发和采用最先进的技术来改变胎儿MRI领域，以满足胎儿干预出现时对更多信息日益增长的需求。

DESCRIPTION (provided by applicant): The fetal period is a time of unparalleled brain growth and development and is arguably the most important time for defining future cognitive potential. Therefore, when fetal brain development is impaired, as it is in many disorders including congenital heart disease (CHD), abnormalities emerge in utero and contribute to lifelong cognitive impairment that cannot be corrected even with optimal postnatal care. This has led to an overwhelming public health need for methods that detect early in utero anatomical and physiological abnormalities to better counsel parents and to better guide development and optimization of fetal interventions (surgical or medical) to prevent or mitigate such long-term consequences. Although there has been ongoing optimism that fetal MRI could fulfill this role, it still remains severely limited by the unique anatomy of the gravid abdomen, the small size of the fetus and, most importantly, fetal motion. As a result, fetal brain MRI lags far behind postnatal brain imaging. In fact, fetal brain MR evaluations remain primarily limited to fast single-shot T2 sequences that have inherently poor brain contrast with spectroscopy, diffusion and perfusion unreliable or impossible with the current methods. Thus, the potential of fetal MRI to provide robust and accurate structural and physiological assessments remains unrealized. We propose to advance fetal MRI using an integrated approach that addresses the entire imaging acquisition process from hardware to pulse sequence design with the following aims: Aim 1. Develop MR Hardware and Anatomical Acquisition Methods. We propose to develop the first anthropomorphic fetal MRI phantom to safely test the feasibility of our developments and ensure SAR safety. We will build the first 128-channel receive phased array for the pregnant abdomen to facilitate image acceleration and improve SNR. We will build on the emerging field of parallel transmission (pTx), and be the first to apply it to fetal imaging with the goal of exciting only th region of the fetal head to minimize SAR, enable further acceleration, and provide a target for prospective motion navigation. Additional speed on the image acquisition will be gained with the development of compressed sensing (CS) techniques for fetal imaging. These improvements will enable improved anatomical images (TSE and MPRAGE); Aim 2. Develop Physiological Acquisition Methods. Use advances in Aim 1 to develop robust diffusion, spectroscopy and perfusion imaging; and Aim 3. Translate to In Vivo Fetal Brain MRI assessment in Congenital Heart Disease. We will assess the ability or our advances to better detect structural and physiological brain abnormalities in CHD compared to current fetal MRI in the same subjects and compared to the advanced protocol in normal controls. In addition we will attempt to detect physiological changes after fetal interventions in hypoplastic left heart syndrome (HLHS). In summary, our goal is to transform the field of fetal MRI by developing and employing state-of-the-art advances on the acquisition end of the fetal MRI experiment to meet the growing demand for more information as fetal interventions emerge.