预言:用于T1,T2,质子密度和非共振映射的分析方法,采用相循环平衡稳定状态自由前置映射
Nils M J Plähn1,2,3, Yasaman Safarkhanlo2,3,4, Berk C Açikgöz1,2,3
1Department of Diagnostic, Interventional and Pediatric Radiology (DIPR), Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.
Magnetic resonance in medicine
|December 23, 2024
概括
一种名为ORACLE的新方法通过分析bSSFP数据简化了T1,T2和质子密度的MRI量化. 它还纠正了低样本扫描中的别名调整,大大减少了扫描时间.
科学领域:
- 磁共振成像 (MRI) 是一种磁共振成像技术.
- 生物医学工程 生物医学工程
- 定量成像技术 定量成像技术
背景情况:
- 定量MRI (qMRI) 对于诊断神经系统疾病至关重要.
- 平衡稳态自由前行 (bSSFP) 序列是高效的,但分析起来却很复杂.
- 精确量化放松时间 (T1,T2) 和质子密度 (PD) 是可靠的qMRI必不可少的.
研究的目的:
- 开发和验证使用复杂线性方程 (ORACLE) 方法编码的非共振分析参数量化.
- 为了使T1,T2,质子密度 (PD) 和非共振效应从阶段循环bSSFP数据的简化和快速量化.
- 引入一种方法来纠正低样本的bSSFP配置文件中的别名化工件,减少扫描时间.
主要方法:
- 甲骨文为bSSFP配置文件提供分析解决方案,可立即量化T1,T2,PD和异共振值.
- 导出了一个别名校正形式主义,以允许bSSFP配置文件的低采样.
- ORACLE被应用于模拟,幻影和10个健康人脑的完全采样的bSSFP数据,结果与参考扫描相比较.
主要成果:
- 甲骨文显示出与模拟和幻影数据 (R2 = 0.99) 的良好一致性.
- 在人类大脑中,T1和T2定量表现出较低的变化系数 (<3.9%) 和与参考方法相比最小的偏差.
- 别名调整有效地消除了不足样本的bSSFP配置文件中的量化错误,显著减少了扫描采集时间.
结论:
- 甲骨文提供了一个简化和加速的方法来从bSSFP数据中量化关键MRI参数 (T1,T2,PD).
- 该方法减少了获取时间,并消除了对生物标记物地图的联合注册的需要.
- 甲骨文促进了更快,更强大的定量核磁共振,具有潜在的临床应用.
相关概念视频
Double Resonance Techniques: Overview
191
Double resonance techniques in Nuclear Magnetic Resonance (NMR) spectroscopy involve the simultaneous application of two different frequencies or radiofrequency pulses to manipulate and observe two distinct nuclear spins. One important application of double resonance is spin decoupling, which selectively suppresses coupling with one type of nucleus while observing the NMR signal from another nucleus, simplifying the spectrum and enhancing resolution.
Spin decoupling is usually achieved by...
Spin decoupling is usually achieved by...
191
Two-Dimensional (2D) NMR: Overview
617
The 1D NMR spectrum of large and complex molecules like natural products has complicated splitting patterns and overlapping signals, which can be easily interpreted using 2-dimensional (2D) NMR. Unlike 1D NMR, 2D NMR has two frequency axes that provide the coupling information between the nucleus A and nucleus B in a molecule. The process from which 2D spectra are obtained has four steps.
The first step is the preparation period, during which nucleus A is excited with a radiofrequency pulse....
The first step is the preparation period, during which nucleus A is excited with a radiofrequency pulse....
617
2D NMR: Overview of Homonuclear Correlation Techniques
168
Homonuclear correlation spectroscopy (COSY) is a powerful technique used in Nuclear Magnetic Resonance (NMR) spectroscopy to study the correlations between nuclei of the same type within a molecule. It provides information about scalar couplings between adjacent nuclei, which helps determine connectivity and structural information. There are several COSY variants, each with its unique strengths and experimental parameters.
COSY90 is the standard two-dimensional (2D) COSY experiment that...
COSY90 is the standard two-dimensional (2D) COSY experiment that...
168
¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)
1.0K
When proton-coupled carbon-13 spectra are simplified by a broadband proton decoupling technique, structural information about the coupled protons is lost. Distortionless enhancement by polarization transfer (DEPT) is a technique that provides information on the number of hydrogens attached to each carbon in a molecule. While the DEPT experiment utilizes complex pulse sequences, the pulse delay and flip angle are specifically manipulated. The resulting signals have different phases depending on...
1.0K
NMR Spectrometers: Radiofrequency Pulses and Pulse Sequences
748
A pulse is a short burst of radio waves distributed over a range of frequencies that simultaneously excites all the nuclei in the sample. Upon passing a radio frequency pulse along the x-axis, the nuclei absorb energy corresponding to their Larmor frequencies and achieve resonance. This shifts the net magnetization vector from the z-axis toward the transverse plane. This angle of rotation of the magnetization vector, or the flip angle, is proportional to the duration and intensity of the pulse.
748
Proton (¹H) NMR: Chemical Shift
1.5K
Organic molecules primarily contain carbon and hydrogen atoms. While all the hydrogen isotopes are NMR-active, protium or hydrogen-1 is the most abundant. It has a significant energy separation between its nuclear spin states due to its large gyromagnetic ratio. As per Boltzmann's distribution, an increase in the energy separation implies a greater excess population of nuclei available for excitation, resulting in a strong NMR absorption signal.
Absorption signals of all the protium nuclei...
Absorption signals of all the protium nuclei...
1.5K


