3D-CE-MRA with High-Resoluton Extended Acquisition

描述(申请人提供)：外周磁共振血管成像(MRA)受限于使用有限的 对比剂的量。“丸状追逐”技术成像了几个 在一次缓慢注射后进行定位。最近的报告表明，这一点 由于可用时间有限，该技术提供的空间分辨率有限 在每个车站。由于潜在的原因，最优的捕获时机很难实现 在同一视场内的对比到达时间的变化。最后， 静脉污染在下肢很常见。 我们正在开发新的高分辨率、稀疏采样的投影 收购。将体积覆盖、空间分辨率和速度结合到一个 单项质量指标，这些时间分辨序列的性能要高出4-13倍 而不是我们之前报道的笛卡尔时间分辨技术(3D技巧)。 这些序列将针对外周血管造影术进行优化。时间分辨率 信息消除了腹部站下方的计时考虑，而 降低对船舶之间填充延迟的敏感度。我们建议使用 延长扫描时间和血管内造影剂以增加信噪比。 这将需要基于空间和的静脉抑制 体素相对于参考动、静脉的时间相关性 感兴趣的区域。在分离后的扩展时间分辨成像 在几个成像站进行注射可以同时增加覆盖范围， 空间分辨率和信噪比。 有针对性地对序列和静脉抑制方法进行优化 使用模拟、幻影和猪。在具体目标2中，成像的能力 在猪模型中延迟血管充盈和抑制静脉。 血管内制剂MS-325将使用DSA进行验证。在具体目标3中， 志愿者和患者将在一个站点进行全剂量的成像 常规对比度。将测量TL以开发模拟 1/3剂量MS-325的热释光。术中X射线血管造影术将用于 对患者MRA研究的验证建议的技术具有类似的 在MRA的其他领域具有潜力。

DESCRIPTION (Provided by Applicant): Peripheral magnetic resonance angiography (MRA) is limited by the need to cover a large field of view using a limited amount of contrast material. The "bolus chase" technique images several stations following a single slow injection. Recent reports indicate that this technique provides limited spatial resolution due to the limited time available at each station. Optimal acquisition timing is difficult due to potential variations in contrast arrival times within the same field of view. Finally, venous contamination is common in the lower extremities. We are developing novel high resolution, sparsely sampled projection acquisitions. Combining volume coverage, spatial resolution and speed into a single quality measure, these time-resolved sequences perform 4-13 times better than our previously reported Cartesian, time-resolved technique (3D TRICKS). These sequences will be optimized for peripheral angiography. Time-resolved information eliminates timing considerations below the abdominal station while reducing sensitivity to filling delays between vessels. We propose to use extended scanning times and intra-vascular contrast material to increase SNR. This will require vein suppression that will be based on the spatial and temporal correlation of voxels relative to reference arterial and venous regions of interest. Extended time-resolved imaging following separate injections at several imaging stations can simultaneously increase coverage, spatial resolution and SNR. The sequences and vein suppression method will be optimized in Specific Aim I using simulations, phantoms and pigs. In Specific Aim 2, the ability to image delayed vessel filling and to suppress veins in a pig model using an intra-vascular agent, MS-325, will be validated using DSA. In Specific Aim 3, volunteers and patients will be imaged at one station with full doses of conventional contrast. Tl will be measured to develop injections that mimic the Tl from 1/3 dose MS-325. Intra-operative X-ray angiography will be used for validation of the patient MRA studies The proposed techniques have similar potential in other areas of MRA.