High-Resolution Lymphatic Mapping of the Upper Extremities with MRI

项目摘要 淋巴水肿是一种淋巴清除受损的病症，导致淋巴细胞水肿和肿胀。 四肢，对生活质量和医疗费用有潜在的破坏性影响。的最常见原因 在美国，水肿来自癌症相关手术。淋巴水肿是渐进的，无法治愈。不 我们知道为什么有些病人会出现水肿，而另一些病人则不会。对尸体的研究表明， 淋巴解剖结构可以在个体之间变化，并且认为这些变化可能增加淋巴结转移的风险。 某些个体发展为水肿。如果这是真的，可以采取措施，以防止水肿， 例如，在手术时进行旁路。然而，没有实际的方法来获得 体内肢体内完整的淋巴解剖图。目前的成像技术受到以下限制： 穿透深度、低分辨率、侵入性和部分覆盖。挑战在于绘制淋巴 通道，直径为0.4-0.8 mm，并从肢体的所有区域追踪至引流淋巴 结该提案的重点是发展一种新型的高分辨率磁共振（MR） 淋巴造影技术（hrMRL）用于活体上肢淋巴映射。hrMRL将为 快速自旋回波序列与定制的可变翻转角、背景减除和 通过压缩感知和深度学习的欠采样加速。第一个目标是建立 并使用phantom以迭代方式优化这些组件中的每一个，然后在10个健康的 受试者，目标是在目标时间内获得整个肢体的淋巴通道图， 20分钟，适合临床采用。在第二个目标中，hrMRL将首先用于获得完整的淋巴结转移。 35例既往接受吲哚菁绿色治疗的健康志愿者上肢解剖图 (ICG)淋巴造影，这将作为一个黄金标准的参考。hrMRL随后将通过以下人员针对ICG进行验证 比较两张地图并确定它们的一致程度。hrMRL还有望解决其他 ICG未检测到的淋巴通道，使我们有机会创建更全面的地图， 表征新的途径，特别是深淋巴通道。如果成功，hrMRL将是 在临床环境中立即产生影响，可以指导避免水肿发作的措施， 将水肿管理算法从支持和纠正疗法之一转变为 预防，目标是减少这种使人衰弱和代价高昂的疾病的发病率。

Project Summary Lymphedema is a condition in which the clearance of lymph is compromised, resulting in edema and swelling of limbs, with potentially devastating impact on quality of life and medical costs. The most common cause of lymphedema in the US is from cancer-related surgery. Lymphedema is progressive and has no cure. It is not known why some patients develop lymphedema while others do not. Studies of cadavers have shown that the lymphatic anatomy can vary across individuals, and it is believed that these variations may increase the risk for certain individuals to develop lymphedema. If this is true, steps may be taken to prevent lymphedema from developing, for example with a bypass at the time of surgery. However, there is no practical way to obtain a complete lymphatic anatomical map within an extremity in vivo. Current imaging techniques are limited by penetration depth, low resolution, invasiveness, and partial coverage. The challenge is to map lymphatic channels, with diameters of 0.4-0.8 mm, and to trace them from all regions of an extremity back to draining lymph nodes. This proposal focuses on the development of a novel high resolution magnetic resonance (MR) lymphography technique (hrMRL) for lymphatic mapping of the upper extremities in living people. hrMRL will be a combination of a fast spin echo sequence with tailored variable flip angles, background subtraction, and acceleration via undersampling with compressed sensing and deep learning. The first aim will be to construct and optimize each of these components in an iterative fashion using phantoms, followed by testing on 10 healthy subjects, with the goal of obtaining maps of the lymphatic channels of an entire extremity within a target time of 20 minutes, suitable for clinical adoption. In the second aim, hrMRL will first be used to obtain full lymphatic anatomic maps of the upper extremity of 35 healthy volunteers who previously underwent indocyanine green (ICG) lymphography, which will serve as a gold-standard reference. hrMRL will then be validated aginst ICG by comparing both maps and determining their degree of agreement. hrMRL is also expected to resolve additional lymphatic channels undetected by ICG, allowing us the opportunity to create more comprehensive maps and to characterize new pathways, in particular the deep lymphatic channels. If successful, hrMRL would be immediately impactful in the clinical setting, where it could guide measures to avoid onset of lymphedema, shifting the lymphedema management algorithm from one of supportive and corrective therapies to one of prevention, with the goal of reducing the incidence of this debilitating and costly disease.