Rapid Robust Pediatric MRI

描述(由申请人提供)：这项工作的目的是快速，稳健的儿科身体核磁共振。磁共振成像是诊断和监测儿科疾病的极佳工具，提供卓越的软组织对比度和高解剖分辨率；与计算机断层扫描(CT)不同，由于儿童患辐射诱发癌症的风险增加，MRI特别吸引人的是缺乏电离辐射。然而，MRI对儿童的影响受到以下因素的限制：(1)通常不合作的患者缺乏技术要求的稳健性和成像微小运动结构的低信噪比(SNR)；(2)长时间检查限制进入，导致运动伪影，通常需要麻醉并伴随风险；(3)研究和开发主要集中在成人身上。因此，儿童往往完全缺乏横断面成像的好处，或者暴露在电离辐射中。方法：这项工作将(1)通过开发针对儿童优化的高密度3特斯拉接收线圈来提高信噪比，(2)采用新的k空间采样策略、先进的运动校正技术和新颖的非线性并行成像重建方法，以减少图像重建失败和运动伪影，从而增强稳健性。这两个发展将使第三个发展成为可能，(3)压缩传感，它通过利用图像稀疏性来在不造成图像伪影的情况下对数据进行欠采样，从而进一步提高成像速度。这三种方法将协同作用，显著提高速度、分辨率和解剖覆盖率。实验将评估(1)专用儿科线圈的SNR增益，(2)标准加速方法的图像质量与通过非相干采样、伪随机排序、运动校正和非线性重建增强的并行成像的图像质量，(3)单独的并行成像与结合并行成像和压缩传感的进一步加速成像之间的诊断等价性，以及(4)这些方法减少儿童MRI麻醉的能力。意义：这项工作将导致快速、可靠、广泛适用的儿科体部MRI方案，减少麻醉，使MRI更安全、更便宜，更容易为儿童提供，将其转变为一种主要的方式，并减少CT辐射负担。这些技术对核磁共振操作员的技能要求较低，便于在社区环境中广泛应用。最后，更快的成像和运动补偿将允许新的MRI应用于儿科和成人疾病。 公共卫生相关性：儿科体部MRI在没有患者合作的情况下对微小的移动解剖结构进行成像提出了独特的挑战，导致需要麻醉、检查时间长以及缺乏稳健性。我们将利用高场强、高密度接收线圈、新的运动校正策略和新的成像加速方法的协同效应来显著提高图像质量和速度。这项工作最终将使更多的身体MRI检查能够在没有镇静或麻醉的情况下稳健地进行，从而提高MRI的安全性和可用性，并减少CT对特别脆弱人群的电离辐射剂量。

DESCRIPTION (provided by applicant): This work aims for rapid, robust pediatric body MRI. MRI is an excellent tool for diagnosis and monitoring of pediatric disease, offering superb soft tissue contrast and high anatomic resolution; unlike computed tomography (CT), particularly attractive is the lack of ionizing radiation, given the increased risk of children to radiation-induced cancer. However, the impact of MRI in children is limited by (1) lack of robustness from the technical demands and low signal to noise ratio (SNR) of imaging small moving structures in an often uncooperative patient, (2) long exams that limit access, cause motion artifacts, and often require anesthesia with attendant risk, and (3) research and development mostly focused on adults. Thus, children often lack the benefits of cross-sectional imaging altogether or are exposed to ionizing radiation. Approach: This work will (1) increase SNR by developing high-density 3 Tesla receive coils optimized for children and (2) incorporate new k-space sampling strategies, advanced motion correction techniques, and novel non-linear parallel imaging reconstruction methods to reduce image reconstruction failure and motion artifacts, thereby increasing robustness. These two developments will enable a third development, (3) compressed sensing, which enables a further increase in imaging speed by exploiting image sparsity to undersample data without causing image artifacts. The three approaches will synergize for dramatic speed, resolution, and anatomic coverage improvements. Experiments will assess (1) SNR gains of a dedicated pediatric coil, (2) image quality of standard acceleration methods versus parallel imaging enhanced with incoherent sampling, pseudorandom ordering, motion- correction, and nonlinear reconstruction, (3) diagnostic equivalence between parallel imaging alone and further accelerated imaging from combined parallel imaging and compressed sensing, and (4) the ability of these methods to reduce anesthesia for pediatric MRI. Significance: This work will lead to fast, robust, broadly-applicable pediatric body MRI protocols with less anesthesia, making MRI safer, cheaper, and more available to children, transforming it into a workhorse modality and decreasing CT radiation burden. The techniques will demand less MRI operator skill, facilitating wide application in the community setting. Finally, faster imaging and motion compensation will permit new MRI applications, for both pediatric and adult disease. PUBLIC HEALTH RELEVANCE: Pediatric body MRI poses unique challenges of imaging small moving anatomic structures without patient cooperation, resulting in a need for anesthesia, long exam times, and lack of robustness. We will exploit synergies of high field strength, high density receive coils, new motion correction strategies, and novel imaging acceleration methods to dramatically improve image quality and speed. This work will ultimately enable more body MRI exams to be performed robustly without sedation or anesthesia, thus increasing MRI safety and availability and decreasing the dose of ionizing radiation from CT to a particularly vulnerable population.