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.
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.
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