Verification and evaluation of internal flow and motion. True magnetic resonance imaging by the phase gradient modulation method.
Verification and evaluation of internal flow and motion. True magnetic resonance imaging by the phase gradient modulation method.
复制标题
内部流动和运动的验证和评估。
DOI：
10.1148/radiology.154.2.3966130
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发表时间：
1985
期刊：
影响因子：
19.7
通讯作者：
Karstaedt
中科院分区：
文献类型：
--
作者：
Paul;R.;Moran;P. Richard;A.;Nolan;Karstaedt
我们报告了对双极相位梯度调制方法的定性和定量评估和验证研究，该方法用于真实的MR内部流动和运动速度成像。速度编码调制使用特殊的相敏重建来提供运动速度和方向敏感图像。真正的运动磁共振成像不依赖于对象参数T1或T2，也不依赖于选择性的活动体积飞行时间计算，也不严格限于液体流动速度。常规MR序列经常引起强烈的偶然相位梯度调制，这可能导致常规MR扫描中的严重伪影，并限制真实运动MR的有用灵敏度。速度编码的多个步骤允许速度谱的分离元素的分辨率，并使得能够抑制所有这种相位伪影困难。一些视图到视图的阶段不一致是被扫描对象固有的，例如，心脏周期中的强烈运动变化；由于这种影响而产生的限制需要在扫描中进行外部修改，例如心脏门控。由于传统的密度信息保留在数据中，与速度编码调制无关，我们建议使用多重编码序列并保存MR原始数据。这些评价和验证显示了相位梯度调制方法在真实流动和运动磁共振成像中的临床应用潜力。
We report qualitative and quantitative evaluation and verification studies of the bipolar phase gradient modulation method for true MR imaging of internal flow and motion velocities. Velocity encoding modulations provide speed-of-motion and direction-sensitive images using special phase-sensitive reconstructions. True motion MR imaging does not depend upon subject parameters, T1 or T2, nor upon selective active-volume time-of-flight calculations, nor is it limited strictly to fluid-flow velocities. Conventional MR sequences often induce strong accidental phase gradient modulations that can cause severe artifacts in conventional MR scans and limit the useful sensitivities of true motion MR. Multiple steps of velocity encoding allow resolution of separate elements of the velocity spectrum, and enable suppression of all such phase-artifact difficulties. Some view-to-view phase inconsistencies are intrinsic to the subject being scanned, e.g., strong motion variations during the heart cycle; limitations due to such effects require external modifications in the scanning, such as cardiac gating. Since conventional density information remains in the data, independent of velocity encoding modulations, we suggest a multiple encoding sequence and saving the MR raw data. These evaluations and verifications demonstrate exciting potential in clinical application for the phase gradient modulation method of true flow and motion MR imaging.
DOI：
10.2214/ajr.142.1.165
发表时间：
1984
期刊：
AJR. American journal of roentgenology
影响因子：
--
作者：
Mills,CM;Brant-Zawadzki,M;Crooks,LE;Kaufman,L;Sheldon,P;Norman,D;Bank,W;Newton,TH
通讯作者：
Newton,TH