Development of A Prepolarized MRI Extremity Scanner

该研究项目的目的是证明一种用于人体肢体成像的超低成本形式的磁共振成像（MRI）的技术可行性，称为预极化MRI。 传统的MRI系统的成本在100万美元到300万美元之间。 我们提出了一种新的预极化MRI系统，使用两个廉价的电磁铁，而不是一个昂贵的超导磁体。 我们的目标是证明一个完整的专用四肢预极化MRI扫描仪成像可以构建不到50,000美元，同时保持良好的图像质量。在过去的五年里，我们在实现这些目标方面取得了巨大进展，包括本月早些时候记录的第一张人体手腕活体图像。 我们的0.43 T预极化MRI手腕成像系统的总资本成本不到35，000美元，不包括MRI数据采集控制台。 我们的主要目标是将成像系统的尺寸扩展到31 cm，以适应膝盖，脚和肘部。 一旦在31 cm口径系统上实现基本成像，我们计划进行几项硬件和软件改进，以增加SNR和对比度灵活性。 我们还计划每月对正常人膝关节软骨的显著性进行一次研究。 两名斯坦福大学的放射科医生将比较正常图像和从0.5 T GE肢体扫描仪获得的金标准图像，并衡量上个月的工程变更是否实际上改善了图像的清晰度。 我们希望在这四年的资助结束时，能够建造一个0.5T预极化MRI系统，其SNR和对比度与传统的0.5T MRI扫描仪相当，资本成本低于50，000美元。如果成功，我们的研究最终可能会导致高质量预极化MRI扫描仪的显著增加，其售价可能低于超声扫描仪的成本。

The objective of this research project is to demonstrate the technical feasibility of an ultra-low-cost form of magnetic resonance imaging (MRI) called Prepolarized MRI for human extremity imaging. Conventional MRI systems cost between 1 million dollars and 3 million dollars. We propose a novel Prepolarized MRI system that uses two inexpensive electromagnets rather than one expensive superconducting magnet. We aim to demonstrate that a complete dedicated extremity Prepolarized MRI scanner imaging can be constructed for less than 50,000 dollars while maintaining excellent image quality. Over the last five years, we have made excellent progress towards these goals, including our first in vivo human wrist images recorded earlier this month. The total capital cost of our 0.43 T Prepolarized MRI wrist imaging system was less than 35,000 dollars, excluding the MRI data acquisition console. Our principal aim is to expand the size of the imaging system to 31 cm to accommodate knees, feet, and elbows. Once basic imaging is achieived on the 31-cm-bore system, we plan several hardware and software improvements to increase the SNR and contrast flexibility. We also plan a monthly study of normal human knee cartilage conspicuity. Two Stanford Radiologists will compare the normal images with gold-standard images obtained from a 0.5 T GE extremity scanner, and gauge whether the previous month's engineering changes actually improved image conspicuity. We hope at the end of this four year grant to have constructed a 0.5 T Prepolarized MRI system with SNR and contrast comparable to a conventional 0.5 T MRI scanner for less than 50,000 dollars in capital costs. If successful, our research could ultimately lead to significantly greater availability of high-quality Prepolarized MRI scanners, which could be sold for less than the cost of an ultrasound scanner.