Improved methods for perfusion imaging with hyperpolarized carbon-13

摘要 灌注障碍是发达国家大多数死亡和残疾原因的基础。 缺血性疾病，包括心肌梗死、中风和肺栓塞是显而易见的 病理灌注的表现。灌注在许多癌症中也起着重要作用。显然，方法 高质量灌注成像是患者放射学评价的重要优先事项。不幸的是， 灌注成像的分辨率、质量和精确度仍然远远低于临床和研究需要。 基于动脉自旋标记（ASL）的技术受到信号强度和短弛豫的限制 标记质子的次数。使用钆造影剂的方法面临以下挑战： 基础灌注和所得到的图像动态之间的复杂关系， 越来越多的安全问题。 在这里，我们建议开发强大的新方法，灌注成像利用超极化 在组织中可自由扩散的碳-13标记的灌注示踪剂。示踪剂具有长T1和T2弛豫 时间和在组织中的长停留时间，并且可以在基本上没有内源性背景的情况下成像。 因此，可以使用鲁棒的成像技术来监测该药剂的时间动态， 高信号强度。我们将开发使用动态成像测量局部血流的方法 技术.超极化灌注成像将与ASL技术进行比较，两种方法 将根据微球灌注定量作为金标准进行验证，以评估准确度， 可扩散极化示踪剂灌注成像的再现性。

Abstract Disorders of perfusion underlie the majority of the causes of mortality and disability in the developed world. Ischemic disorders, including myocardial infarction, stroke, and pulmonary embolism are obvious manifestations of pathologic perfusion. Perfusion also plays a major role in many cancers. Clearly, methods for high quality perfusion imaging are an important priority for radiologic evaluation of patients. Unfortunately, the resolution, quality, and accuracy of perfusion imaging is still far inferior to the clinical and research needs. Techniques based on arterial spin labeling (ASL) are limited by signal strength and by the short relaxation times of labeled protons. Methods that make use of gadolinium contrast agents face challenges arising from the complex relationship between the underlying perfusion and the resulting image dynamics, in addition to growing safety concerns. Here we propose to develop robust new methods for perfusion imaging by making use of a hyperpolarized carbon-13 labeled perfusion tracer that is freely diffusible in tissue. The tracer has long T1 and T2 relaxation times and long residence times in tissue, and can be imaged with essentially no endogenous background. Consequently, the temporal dynamics of this agent can be monitored using robust imaging techniques with high signal strength. We will develop methods for measuring local blood flow using dynamic imaging techniques. Hyperpolarized perfusion imaging will be compared against ASL techniques, and both methods will be validated against microsphere perfusion quantitation as a gold standard to assess the accuracy and reproducibility of perfusion imaging with diffusible polarized tracers.