MRI Image Guided Radiation Therapy (IGRT) system with low cost, highly stable mag

描述（由申请人提供）：ViewRay 的 Renaissance" System 1000 MRI 图像引导放射治疗 (IGRT) 系统的全面开发进展正受到全球氦气日益短缺的威胁。这项开创性技术旨在治疗腹部癌性肿瘤，因为身体机能会导致显着的器官移位，从而使精确的剂量输送变得困难或不可能。液氦目前对于当今低温铌钛 (NbTi) 基超导磁体的操作至关重要。全球氦气的消耗速度超过了世界各地现有天然气井的容量（氦气是一些天然气井的副产品），美国正在出售战略储备以稳定价格，但收效甚微；各种来源的预测都表明，2010 年至 2015 年及以后的时间范围内，氦气将出现严重短缺和价格上涨。三大 MRI 制造商已经制定了开发计划，旨在从再冷凝液氦浴冷却转换为干式传导冷却，再到使用二硼化镁 (MgB2) 超导体的制冷机。Hyper Tech 与这三个制造商都制定了积极的计划，以利用二硼化镁 (MgB2) 超导体。二硼化镁超导体具有比目前使用的铌钛 (NbTi) 高出整整 30 K 的超导性能。相同的线材形式适用于大型磁体制造，因为需要宽的温度裕度来适应磁体中的温度梯度，即使没有氦气短缺带来的紧迫性，对于所有 MRI 制造商来说，将其背景磁体从液氦浴冷却转换为干传导冷却在标准 NbTi MRI 磁体中具有约 2000 升的液氦库存，但仍存在始终存在的危险。现有的所有 MRI 装置都需要爆破片和大型排气管，以防止因爆破片故障而导致的过压。这些因素会对 MRI 的初始价格和后续维护产生重大成本影响。显着降低其商业化“Renaissance”系统 1000 的单位成本的途径。在此计划期间，Hyper Tech 将进行必要的研究，以便使用其 MgB2 超导线材开发和制造无氦背景磁体系统。我们将向 ViewRay 提供磁体系统，ViewRay 将把它整合到他们的 Renaissance" System 1000 MRI IGRT 系统中，并进行成像测试，以验证磁体系统的整体性能与目前基于 NbTi 超导磁体的成像系统相比。这将导致对与 Hyper Tech 的基于 MgB2 的背景磁体系统完全集成的 IGRT 进行临床验证。 公共健康相关性：使用 Hyper Tech 的二硼化镁超导磁体的 ViewRay Renaissance" System 1000 将展示第一个真正的实时 MRI 图像引导放射治疗 (IGRT) 系统，该系统可以在器官移动的情况下以高精度向恶性肿瘤提供伽马辐射。 Hyper Tech MgB2 磁体系统将显着降低 ViewRay 癌症治疗技术的成本和持续维护成本。此外，该磁体系统比目前使用的磁体系统更安全且不易淬火。

DESCRIPTION (provided by applicant): Progress toward full development of ViewRay's Renaissance" System 1000 MRI image guided radiation therapy (IGRT) system is being threatened by the growing shortage of helium worldwide. This pioneering technology is aimed at treating cancerous tumors in the abdomen where bodily functions cause significant organ displacements making precise dose delivery difficult or impossible. Liquid helium is presently essential for operation of present day low temperature niobium-titanium (NbTi) based superconductor magnets. Helium worldwide is being depleted at a rate exceeding the capacity of the current natural gas wells (helium is a byproduct of some natural gas wells) around the world. The US strategic reserves are being sold off to stabilize the price but to little avail; the price of helium continues to rise. Projections from a variety of sources all point to major shortages and the price increases in the 2010-2015 time frame and beyond. This will threaten all helium users but most of all the MRI industry. Already, the three major MRI manufacturers, have development programs aimed at converting from re-condensing liquid helium bath cooling to dry conduction cooling to cryocoolers using magnesium diboride (MgB2) superconductors. Hyper Tech has active programs with all three to utilize magnesium diboride (MgB2) superconductors. Magnesium diboride superconductors have the unique property of being superconducting a full 30 K higher than the currently used niobium titanium (NbTi) while being in the same wire form suitable for large magnet manufacturing. MgB2 enables converting from the liquid helium bath cooling to conduction cooling because of this wide temperature margin needed to accommodate temperature gradients in the magnet. Even without the urgency brought on by the helium shortage, it is cost effective to all MRI manufacturers to transition their background magnets from liquid helium bath cooling to dry conduction cooling. With an inventory of ~2000 liters of liquid helium in a standard NbTi based MRI magnet, there is the ever present danger of a quench and sudden release of gaseous helium. A rupture disc and large exhaust duct to the outside are required for all present MRI installations. In addition, the dewar and vacuum enclosure must be ASME pressure vessel certified in case of an over pressure due to a failed rupture disc. These factors make a significant cost impact on the initial price of an MRI and the follow-on maintenance. This Phase I, Phase II Fast Track SBIR endeavors to remove the helium shortage obstacle facing ViewRay's development while at the same time providing an avenue to significantly lower the unit cost of their commercialized Renaissance" System 1000. During this program Hyper Tech will perform the necessary research in order to develop and fabricate a helium free background magnet system using its MgB2 superconductor wire. We will supply the magnet system to ViewRay who will incorporate it into their Renaissance" System 1000 MRI IGRT system and perform imaging tests to verify the overall magnet system performance compared with the present NbTi superconducting magnet based imaging system. This will lead to clinical validation of the fully integrated IGRT with Hyper Tech's MgB2 based background magnet system. PUBLIC HEALTH RELEVANCE: The first true, real time MRI image guided radiation therapy (IGRT) system that delivers gamma radiation to malignant tumors with pinpoint accuracy in spite of organ movement will be demonstrated by ViewRay Renaissance" System 1000 using Hyper Tech's magnesium diboride superconducting magnets. The Hyper Tech MgB2 magnet system will significantly lower the cost and on-going maintenance costs of ViewRay's cancer treatment technology. In addition, the magnet system will be safer and less prone to quenching than presently used magnet system.