SBIR Phase I: Improving MRI Guided Thermal Therapies by Designed Magnetic Nanoparticles

该SBIR第一阶段项目涉及粒子的创建，这些粒子将允许人们在磁共振成像（MRI）测量中看到温度图。 这是一个重大的进步，因为传统的温度测量通常是侵入性的，只允许单点温度测量，并可能干扰治疗和成像仪器。该技术具有生物相容性和微创性，可在人体深处快速进行3D温度映射。所提出的材料和技术可与MRI引导的热手术一起使用，该手术可取代各种癌症的基于解剖刀的手术，从而改善患者结局并缩短手术时间。该方法还可用于改善原发性震颤、子宫纤维化和动静脉畸形的治疗。在这些治疗中，必须不断监测整个受影响区域的温度。由于当前使用的温度测量方法的限制，这些微创MRI引导的程序不经常使用或花费比期望的长得多的时间，因为外科医生通常必须解决失败的温度测量。这项提案中的工作可以改变目前的MRI引导测温方法，显著减少手术时间和成本，并改善患者的预后。 该提案开发了一种新颖的微创方法，用于创建叠加在解剖MRI图像上的温度图。该技术使用了一种新型的温度敏感传感器，以磁性纳米颗粒的形式，并最终可用于人体或其他组织。 关键思想是，嵌入组织中的磁性颗粒将产生局部偶极磁场，该局部偶极磁场将调制（静态或动态）MRI扫描仪的主静磁场的均匀性。 这改变了组织的核弛豫时间并加宽了核磁共振（NMR）线宽，最终导致MRI图像亮度的局部变化。 粒子的磁化被设计成随温度而变化，因此结果是温度相关的。然后可以校准加权梯度回波MR图像中的不同灰度以获得温度的空间图。例如，这可以直接应用于在MRI引导的热介入手术期间向外科医生提供实时温度信息以治疗癌症。这些新的对比度传感器可以在低于和高于人体温度的宽温度范围内工作，产生精确度优于1摄氏度的温度空间图。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This SBIR Phase I project involves the creation of particles that will allow one to see a map of temperature within a Magnetic Resonance Imaging (MRI) measurement. This is a significant advancement because conventional thermometry is usually invasive, allows only single point temperature measurements, and may interfere with the therapeutic and imaging instrument. The proposed technology is designed to be biocompatible and minimally invasive, leading to fast 3D temperature mapping deep in the human body. The proposed materials and techniques can be used with MRI-guided thermal procedures which can replace scalpel-based surgery for a variety of cancers, improving patient outcomes and reducing surgical time. The method can also be used to improve treatments for essential tremor, uterine fibrosis and arteriovenous malformation. In these treatments, the temperature in the entire affected region must be constantly monitored. Due to the limitations of the currently used temperature measurement methods, these minimally invasive MRI-guided procedures are not frequently used or take considerably longer time than desired because surgeons often must work around failed temperature measurements. The work in this proposal could transform current methods of MRI-guided thermometry, significantly reducing surgery time and cost as well as improving patient outcomes. This proposal develops a novel, minimally-invasive method of creating temperature maps superimposed on anatomical MRI images. The technology uses a new type of temperature-sensitive sensor, in the form of magnetic nanoparticles, and could ultimately be used within human or other tissues. The key idea is that magnetic particles embedded in tissue will create a local dipole magnetic field that will modulate (statically or dynamically) the homogeneity of the main static magnetic field of the MRI scanner. This changes the nuclear relaxation times of the tissue and broadens the Nuclear Magnetic Resonance (NMR) linewidth, ultimately leading to local changes in the brightness of the MRI image. The magnetization of the particles is engineered to change with temperature, and therefore the results are temperature dependent. Different shades of gray in the weighted gradient echo MR images, can then be calibrated to obtain a spatial map of temperature. This has immediate application in providing real-time temperature information to the surgeon during MRI-guided thermal interventional procedures to treat cancer, for example. These new contrast sensors can operate in a wide temperature range both below and above the human body temperature, producing spatial maps of temperature with an accuracy better than 1 degree Celsius.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.