Rapid Robust Pediatric MRI

描述（由申请人提供）：这项工作旨在快速，强大的儿童身体MRI。MRI是诊断和监测儿科疾病的极好工具，提供极好的软组织对比和高解剖分辨率；与计算机断层扫描（CT）不同的是，考虑到儿童患辐射诱发癌症的风险增加，它特别吸引人的地方是没有电离辐射。然而，MRI对儿童的影响受到以下因素的限制：(1)在通常不合作的患者中成像小运动结构的技术要求和低信噪比（SNR）缺乏鲁棒性；(2)长时间的检查限制了访问，导致运动伪影，并且通常需要麻醉并伴有风险；(3)研究和发展主要集中在成人。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下。方法：本工作将(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来减少图像重建失败和运动伪影，从而提高鲁棒性。这两个发展将推动第三个发展，(3)压缩传感，它通过利用图像稀疏性来欠采样数据而不会造成图像伪影，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、分辨率和解剖覆盖范围。实验将评估(1)专用儿科线圈的信噪比增益，(2)标准加速方法与通过非相干采样、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)单独并行成像与通过并行成像和压缩感知联合进一步加速成像之间的诊断等效性，以及(4)这些方法减少儿科MRI麻醉的能力。意义：这项工作将带来快速、稳健、广泛适用的儿童全身MRI方案，减少麻醉，使MRI更安全、更便宜、更容易获得，使其成为一种主要方式，减少CT辐射负担。该技术对核磁共振操作员技能的要求较低，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。

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.