Rapid Robust Pediatric MRI

描述（由申请人提供）：这项工作旨在实现快速、稳健的儿科身体MRI。MRI是诊断和监测儿科疾病的优秀工具，提供极好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，特别有吸引力的是缺乏电离辐射，因为儿童患辐射诱发癌症的风险增加。然而，MRI在儿童中的影响受到以下因素的限制：（1）技术要求缺乏鲁棒性，对通常不合作的患者进行小运动结构成像的信噪比（SNR）较低，（2）长时间检查限制了进入，导致运动伪影，并且通常需要麻醉，伴随风险，以及（3）研究和开发主要集中在成人身上。因此，儿童往往缺乏横断面成像的好处，或者暴露于电离辐射。方法：这项工作将（1）通过开发针对儿童优化的高密度3 T接收线圈来提高SNR，（2）结合新的k空间采样策略、先进的运动校正技术和新型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，从而提高鲁棒性。这两个发展将实现第三个发展，（3）压缩传感，其通过利用图像稀疏性对数据进行欠采样而不引起图像伪影来实现成像速度的进一步提高。这三种方法将协同作用，以提高速度、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）单独并行成像与来自组合并行成像和压缩感知的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。重要性：这项工作将导致快速，强大，广泛适用的儿科身体MRI协议，减少麻醉，使MRI更安全，更便宜，更适合儿童，将其转变为主力模式并减少CT辐射负担。该技术将需要较少的MRI操作员技能，促进在社区环境中的广泛应用。最后，更快的成像和运动补偿将允许新的MRI应用，用于儿科和成人疾病。 公共卫生相关性：儿科身体MRI在没有患者配合的情况下对小的移动解剖结构成像提出了独特的挑战，导致需要麻醉、检查时间长和缺乏鲁棒性。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作用，大幅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.