Exploration of Ultrasound-Activated Bubbles as a Switchable MRI Contrast Agent

微泡和纳米泡已经用于超声成像以突出病变组织，特别是 肿瘤，以帮助医生检测疾病。这些气泡也可以填充治疗药物， 当它们在所需位置时使用超声能量弹出。虽然这些基于气泡的对比 虽然药物使肿瘤更容易在超声图像上看到，但识别解剖结构仍然具有挑战性。 由于该模态的软组织对比度相对较差，因此在超声图像中的结构中存在缺陷。超声 成像还受限于成像所需的较高频率下的穿透深度， 包括身体成像在内的一些应用具有挑战性。另一方面，磁共振成像（MRI） 能够对肝脏等大型器官进行成像，具有精致的对比度和完整的覆盖范围。的缺点 MRI的另一个缺点是其低灵敏度使得小的癌性病变的检测具有挑战性，并且 MRI无法无创启动肿瘤。 该项目的目标是探索使用超声激活的纳米气泡作为可切换的MRI造影剂 该试剂能够快速有效地检测和治疗转移性疾病。在这里， 在MRI上存在微气泡和/或纳米气泡，无论是否应用超声能量 信号将被测试。我们假设仅仅是小气泡的存在对MRI的影响很小 信号，但是MRI信号可以通过施加超声能量在快速的时间尺度上显著地改变 到泡泡。气泡的配方将被重新审视，以最大限度地提高它们改变周围环境的能力。 磁场，从而影响MRI信号，并将测试各种形式的MRI数据收集， 快速定位气泡。请注意，这种造影剂的可转换性质，这是真正独特的， MRI，将对如何收集MRI数据产生深远的影响，为创新性 获取数据和生成图像的策略。这一探索性项目将为测试 这种新型的可切换MRI造影剂在体内用于稳健检测和有效治疗小转移性肿瘤， 肿瘤的请注意，该团队包括一位超声造影剂纳米气泡设计专家，一位MRI 以开发创新的数据收集和图像重建方法而闻名的物理学家，以及第二位 MRI物理学家，既有MRI/超声联合检查的经验，又能使用所需的工具， 执行这项工作。

Micro- and nanobubbles have been used in ultrasound imaging to highlight diseased tissue, specifically tumors, to aid physicians in detecting disease. These bubbles can also be filled with therapeutic drugs, and popped using ultrasound energy when they are at the desired location. While these bubble-based contrast agents make tumors easier to see on ultrasound images, it can still be challenging to recognize anatomical structures in ultrasound images due to the relatively poor soft tissue contrast of this modality. Ultrasound imaging is also limited in penetration depth at the higher frequencies needed for imaging, which can make some applications including body imaging challenging. On the other hand, Magnetic Resonance Imaging (MRI) is able to image large organs such as the liver with exquisite contrast and complete coverage. The drawback of MRI is that its low sensitivity makes the detection of small cancerous lesions challenging, and treatment of the tumor cannot be initiated non-invasively with MRI. The goal of this project is to explore the use of ultrasound-activated nanobubbles as a switchable MRI contrast agent to enable the rapid and effective detection and treatment of metastatic disease. Here, the effect of the presence of micro- and/or nanobubbles, both with and without the application of ultrasound energy, on the MRI signal will be tested. We hypothesize that the mere presence of small bubbles will have little impact on the MRI signal, but that the MRI signal can be dramatically altered on a rapid timescale by applying ultrasound energy to the bubbles. The formulation of the bubbles will be revisited to maximize their ability to alter the surrounding magnetic field and thus affect the MRI signal, and various forms of MRI data collection will be tested to enable rapid localization of the bubbles. Note that the switchable nature of this contrast agent, which is truly unique in MRI, will have a profound impact on how the MRI data can be collected, opening the door for innovative strategies for acquiring data and generating images. This exploratory project will pave the way for testing of this novel switchable MRI contrast agent in vivo for robust detection and efficient treatment of small metastatic tumors. Note that the team includes an expert on nanobubble design for ultrasound contrast agents, an MRI physicist renowned for developing innovative data collection and image reconstruction methods, and a second MRI physicist who has both the experience in combined MRI/ultrasound and access to the tools needed to perform this work.