HIGH SPEED MRI TUMOR IMAGING

由于最近在快速成像技术和硬件MRI方面的突破， 在诊断腹部肿瘤方面有可能超过CT。 MRI 有两个基本的优点：它没有电离辐射， 上级软组织对比度。 常规MRI的缺点是 对运动的敏感性和低分辨率。 这里提出的工作 直接应对这些挑战。 在第一阶段的赠款，我们已经开发了几个新的快速 成像技术显然有潜力使肿瘤成像 一个可行的临床工具 其中包括高速 提供必要灵敏度的交错螺旋序列， 免疫运动，并在肿瘤的临床成像对比度 腹部 这种潜力在对50多个 患者和更多的正常志愿者。 这些技术包括 新的RARE螺旋序列，承诺改善信噪比和分辨率。 在 此外，我们还研究了几种体积序列，其中3D kappa- 空间被有效地扫描并且对运动不敏感。 我们有 开发了几种荧光透视序列， 问题研究 对于不能屏住呼吸的不合作患者，我们有 开发了一个非屏气序列使用导航器为基础的运动 检测系统，其在真实的时间中重新获取被 过度运动。 在这次更新中，我们建议继续开发几个重要的 腹部成像协议，以及几个关键的核心技术， 具有时变梯度的高速成像。 最终，这一机构 工作将产生一套优化的临床方案，包括 屏气T/1和T/2加权序列，非屏气，运动- 补偿的T/1和T/2加权序列以及荧光透视序列。 虽然这些都是为当前的硬件设计的，但每一个都可以适应 利用下一代梯度和射频的功能 硬件目前正在释放。 新协议和核心技术 将使用临床扫描进行优化。

Due to recent breakthroughs in fast imaging techniques and hardware MRI now has the potential to surpass CT for diagnosing abdominal tumors. MRI has two fundamental advantages: it lacks ionizing radiation, and it shows superior soft tissue contrast. The disadvantages of conventional MRI are sensitivity to motion and inferior resolution. The work proposed here directly addresses these challenges. During the first phase of this grant we have developed several new rapid imaging techniques that clearly have the potential to make tumor imaging in the abdomen a viable clinical tool. These include high-speed interleaved spiral sequences that provide the necessary sensitivity, immunity to motion, and contrast for clinical imaging of tumors in the abdomen. This potential has been vividly confirmed after imaging over 50 patients and many more normal volunteers. These techniques include a novel RARE-spiral sequence that promises improved SNR and resolution. In addition we have studied several volumetric sequences in which 3D kappa- space is scanned efficiently and with insensitivity to motion. We have developed several fluoroscopic sequences to enable critical dynamic studies. For uncooperative patients who cannot hold their breath, we have developed a non-breath-held sequence using navigator-based motion detection system that in real time reacquires all data corrupted by excessive motion. In this renewal we propose to continue developing several important abdominal imaging protocols and also several core techniques critical to high speed imaging with time-varying gradients. Ultimately, this body of work will produce a suite of optimized clinical protocols including breath-held T/1 and T/2 weighted sequences, non-breath-held, motion- compensated T/1 and T/2 weighted sequences, and a fluoroscopic sequence. Although these are designed for current hardware, each can be adapted to exploit the capabilities of the next generation of gradient and RF hardware currently being released. The new protocols and core techniques will be optimized using anecdotal clinical scans.