以上是一些非常浅显的MRI basic physics 的过程梳理,后面会继续写一些slicing,frequency encoding & phase encoding的概念,然后是K-space trajectory和最后的计算机成像。 参考文献: 1.核磁共振是什么?什么是自旋?核磁共振的基本原理 妈咪说https://www.youtube.com/watch?v=Sebo6v7QTek&t=779s 2. QUESTIONS AND A...
MRI Physics #18 - Radiology Physics Course - Coherent, Incoherent 'Spoiled' and bili_21686626238 0 0 MRI Physics #8 - Radiology Physics Course - Frequency Encoding Gradient _ MRI Si bili_21686626238 0 0 X-ray Physics Course #29 - Radiology Physics Course #36 - Direct Thin Film Trans bi...
The data to fillk-space is taken directly from the MR signal. Because gradients have been applied for phase and frequency encoding, the MR signal is already in a Fourier-like format suitable for filling thek-space matrix. 填充k空间的数据直接来源于 MR 信号。由于 MR 信号包含了相位编码与频率编...
Phase Encoding Phase Encoding 相位编码 Gpe 0 Tpe 相位? Similarities and Differences Between Frequency and Phase Encodings Both utilizes gradient fields for encoding Phase encoding is done by pre-frequency encoding the signal for a short time interval * * 2D Spatial Encoding – Frequency and Phase ...
MRI空间编码k空间与重建.ppt,Similarities and Differences Between Frequency and Phase Encodings Both utilizes gradient fields for encoding Phase encoding is done by pre-frequency encoding the signal for a short time interval * * 2D Spatial Encoding – Freq
phase- or frequency-encoding is optimal. Trial and error may be necessary. I have been pleasantly surprised on numerous occasions that by simply swapping phase- and frequency-encoding directions empirically, very severe susceptibility artifacts may be reduced or moved away from from the area of ...
In most radial and spiral imaging methods, frequency- and phase-axes do not maintain fixed relationships to the cardinal anatomic directions (left-right, superior-inferior, etc.) Instead, phase- and frequency-encoding directions change continually as the trajectory sweeps or rotates around the center...
In order to use both phase and frequency encoding, we first turn on the phase encoding gradient, then turn it off; this happens during the time we are waiting for the echo. At the time of the echo, we turn on the frequency-encoding gradient only. This changes the frequencies of the ...
VENC：velocity encoding流速编码 NPW：no phase wrap去相位卷褶 IR：inversion recovery反转恢复 MT：magnetization transfer磁化转移(磁化传递)FT：fourier transform傅里叶变换 VPS：Views Per Segment每段视图 BSP TI：blood suppression TI血夜抑制反转时间(IFIR参数)序列 SE：spin echo自旋回波 FSE：fast spin echo...
PWI：perfusion weighted imaging灌注加权成像 BOLD：blood oxygenation level dependent⾎氧⽔平依赖 RF：Radio Frequency射频 TR：repetition time重复时间 TE：echo time回波时间(Effective TE有效TE)Minimum TE：部分回波技术 TI：inversion time反转时间 ES：echo space回波间隙 ETL：echo train length回波链长度 ...