Accelerated Electron Paramagnetic Resonance Imaging

加速电子顺磁共振成像

• 批准号: 8385868
• 负责人: Alan Blair McMillan
• 金额: $ 18.81万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-15 至 2014-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8385868
• 关键词: Acceleration; Acute; Animals; Breathing; Calibration; Carbogen; Carbon Dioxide; Characteristics; Chronic; Cytotoxin; Data; Dose; Electron Spin Resonance Spectroscopy; Exhibits; Fluorocarbons; Frequencies; Gases; Hypoxia; Image; Imaging Techniques; Implant; Individual; Injection of therapeutic agent; Knowledge; Leg; Magnetic Resonance Imaging; Magnetic Resonance Spectroscopy; Measurement; Methodology; Methods; Modality; Mus; Nuclear; Oxygen; Partial Pressure; Pathway interactions; Pattern; Physiology; Positron-Emission Tomography; Radial; Radiation; Radiation therapy; Resistance; Resolution; Sampling; Solid Neoplasm; Techniques; Therapeutic; Three-Dimensional Image; Time; Tissues; Tumor Oxygenation; Vascular Endothelial Cell; blood oxygen level dependent; chemotherapy; cost; data acquisition; data space; density; image reconstruction; improved; in vivo; insight; molecular imaging; neoplastic cell; new technology; novel; reconstruction; response; single photon emission computed tomography; tissue oxygenation; transcription factor; treatment effect; treatment response; tumor

DESCRIPTION (provided by applicant): Tumors that are oxygen-starved (hypoxic) and exhibit cycling hypoxia (where regions within a tumor fluctuate between normoxic and hypoxic levels) have been shown to be resistant to treatment. While knowledge of the hypoxic status of tumors could inform an improved therapeutic course, quantitative assessment of hypoxia (both static and cycling) via in vivo imaging is difficult. Electron paramagnetic resonance imaging (EPRI) has been shown to provide direct quantification of tissue oxygenation (pO2) in small animals. EPRI is advantageous in being low cost and highly specific to image tumor oxygenation. While both chronic and intermittent hypoxia can be visualized within solid tumors using existing techniques, the spatial and temporal resolution is currently sub-optimal. The technical aim of this project is to develop new image acquisition strategies for EPRI to improve spatial resolution and reconstructed image framerate. Key to the implementation of these ideas will be the incorporation of radial data sampling techniques. These techniques, when combined with iterative image reconstruction, have been shown to provide good results for dynamic imaging in spite of relaxed data sampling requirements, thus providing significant acceleration compared to previous techniques. These new methods will enable improved spatial and temporal resolution and allow novel insights into study of the tumor microenvironment with a pharmcokinetic assessment of hypoxic tumors that is currently not possible with any other imaging technique. These improvements will be demonstrated in dynamic imaging of SCCVII solid tumors implanted in the legs of mice by using accelerated EPR imaging to characterize chronic and intermittent hypoxia in response to breathing different gas mixtures. PUBLIC HEALTH RELEVANCE: Knowledge of oxygen-starved (hypoxic) regions of tumors, which are known to be treatment-resistant, could suggest the selection of optimal therapy, however, quantitative assessments of hypoxia are difficult to obtain non-invasively. Quantification of tissue oxygenation (pO2) with dynamic imaging is possible with electron paramagnetic resonance imaging (EPRI), and this developing modality has been successfully demonstrated in in vivo. Unfortunately, current EPRI techniques are limited in spatial and temporal resolution; thus, this proposal will develop methods to allow substantial improvements in EPR imaging, which has the promise to become a low cost and highly specific modality to spatially and temporally characterize tumor hypoxia.

描述（由申请人提供）：已证明缺氧（缺氧）并表现出循环缺氧（肿瘤内区域在常氧和缺氧水平之间波动）的肿瘤对治疗具有抗性。虽然了解肿瘤的缺氧状态可以改善治疗过程，但通过体内成像定量评估缺氧（静态和循环）是困难的。电子顺磁共振成像（EPRI）已被证明可以直接量化小动物的组织氧合（pO2）。EPRI的优势在于低成本和对肿瘤氧合成像的高度特异性。虽然使用现有技术可以在实体肿瘤内可视化慢性和间歇性缺氧，但空间和时间分辨率目前是次优的。本项目的技术目标是为EPRI开发新的图像采集策略，以提高空间分辨率和重建图像帧率。实现这些想法的关键将是纳入径向数据采样技术。这些技术，当与迭代图像重建相结合时，已经被示出为提供良好的结果，用于动态成像，而不管宽松的数据采样要求，因此与先前的技术相比提供显著的加速。这些新方法将提高空间和时间分辨率，并允许对肿瘤微环境的研究进行新的见解，对缺氧肿瘤进行药物动力学评估，这是目前任何其他成像技术都不可能实现的。这些改进将在植入小鼠腿部的SCCVII实体瘤的动态成像中证明，通过使用加速EPR成像来表征响应于呼吸不同气体混合物的慢性和间歇性缺氧。 公共卫生相关性：已知肿瘤的氧饥饿（缺氧）区域具有治疗抗性，其知识可以建议选择最佳治疗，然而，缺氧的定量评估难以非侵入性地获得。利用电子顺磁共振成像（EPRI）可以通过动态成像定量组织氧合（pO2），并且这种显影模式已在体内成功证实。不幸的是，目前的EPRI技术是有限的空间和时间分辨率，因此，该提案将开发的方法，允许在EPR成像，这有希望成为一个低成本和高度特定的模式，以空间和时间表征肿瘤缺氧的实质性改进。