What is GE EPI?
What is GE EPI?
Gradient-echo (GE) echo-planar imaging (EPI) is the method of choice in blood-oxygenation level-dependent (BOLD) functional MRI (fMRI) studies, as it demonstrates substantially higher BOLD sensitivity than its spin-echo (SE) counterpart.
What is planar imaging?
Planar imaging is the acquisition of 2D nuclear images, similar to plain films in x-ray imaging.
What is AK space?
The k-space is an extension of the concept of Fourier space well known in MR imaging. The k-space represents the spatial frequency information in two or three dimensions of an object. The k-space is defined by the space covered by the phase and frequency encoding data.
What is the difference between SPECT and Planar?
Overall, SPECT imaging yielded a higher sensitivity (93% vs 82% for SPECT and planar imaging respectively, p < 0.05), especially in the inferior and anterior regions. SPECT was also more sensitive for the detection of a single-vessel disease (90% vs 74% for SPECT and planar imaging respectively, p < 0.01).
Who created echo planar imaging?
In 1977, Sir Peter Mansfield of the University of Nottingham described the general principles of echo-planar imaging (,1).
What is T1 and T2 physics?
The most common MRI sequences are T1-weighted and T2-weighted scans. T1-weighted images are produced by using short TE and TR times. The contrast and brightness of the image are predominately determined by T1 properties of tissue. Conversely, T2-weighted images are produced by using longer TE and TR times.
What is echo planar (epi)?
The echo planar (EPI) is the fastest acquisition method in MRI (100 ms / slice), but with limited spatial resolution. It is based on: an excitation pulse, possibly preceded by magnetization preparation
What is electecho planar imaging and how does it work?
Echo planar imaging is performed using a pulse sequence in which multiple echoes of different phase steps are acquired using rephasing gradients instead of repeated 180 degree radio frequency pulses following the 90°/180° in a spin echo sequence.
What is a gradient echo based EPI sequence?
In case of a gradient echo based EPI sequence the initial part is very similar to a standard gradient echo sequence. By periodically fast reversing the readout or frequency encoding gradient, a train of echoes is generated. EPI requires higher performance from the MRI scanner like much larger gradient amplitudes.
What does epi stand for?
Sequences. The echo planar (EPI) is the fastest acquisition method in MRI (100 ms / slice), but with limited spatial resolution. It is based on: an excitation pulse, possibly preceded by magnetization preparation continuous signal acquisition in the form of a gradient echo train, to acquire total or partial k-space…
