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Result : Searchterm 'sequence' found in 30 terms [] and 347 definitions []
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Contrast Enhanced Gradient Echo SequenceInfoSheet: - Sequences - 
Intro, 
Overview, 
Types of, 
etc.
 
Contrast enhanced GRE sequences provide T2 contrast but have a relatively poor SNR. Repetitive RF pulses with small flip angles together with appropriate gradient profiles lead to the superposition of two resonance signals.
The first signal is due to the free induction decay FID observed after the first and all ensuing RF excitations.
The second is a resonance signal obtained as a result of a spin echo generated by the second and all addicted RF-pulses.
Hence it is absent after the first excitation, it is a result of the free induction decay of the second to last RF-excitation and has a TE, which is almost 2TR. For this echo to occur the gradients have to be completely symmetrical relative to the half time between two RF-pulses, a condition that makes it difficult to integrate this pulse sequence into a multiple slice imaging technique. The second signal not only contains echo contributions from free induction decay, but obviously weakened by T2-decay. Since the echo is generated by a RF-pulse, it is truly T2 rather than T2* weighted. Correspondingly it is also less sensitive to susceptibility changes and field inhomogeneities.
Companies use different acronyms to describe certain techniques.
Different terms (see also acronyms) for these gradient echo pulse sequences:
CE-FAST Contrast Enhanced Fourier Acquired Steady State,
CE-FFE Contrast Enhanced Fast Field Echo,
CE-GRE Contrast Enhanced Gradient-Echo,
DE-FGR Driven Equilibrium FGR,
FADE FASE Acquisition Double Echo,
PSIF Reverse Fast Imaging with Steady State Precession,
SSFP Steady State Free Precession,
T2 FFE Contrast Enhanced Fast Field Echo (T2 weighted).

In this context, 'contrast enhanced' refers to the pulse sequence, it does not mean enhancement with a contrast agent.
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Spectroscopy - Education - MRI Technician and Technologist Career - Contrast Agents - - Software
 
Peak Arterial Enhancing K-Space SequenceMRI Resource Directory:
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(PEAKS) This function offers consistent arterial enhancement for contrast enhanced MRA studies, augmenting the k-space with filling flexibility.
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Chemical Shift Selective Imaging SequenceInfoSheet: - Sequences - 
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(CHESS) A sequence for water suppression in proton MR spectroscopy and for water or fat suppression in MR imaging. This technique uses a frequency-selective 90° pulse to selectively excite the water signal, followed by a spoiler gradient to dephase the resulting magnetization. The gradients may be repeated several times in different directions to increase its effectiveness.

See also Chemical Shift Imaging and Chemical Shift.
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Spin Echo Sequence for Spatial LocalizationInfoSheet: - Sequences - 
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(DEPTH) A sequence with multiple RF pulses to enable acquiring data from only selected regions.
See Depth Pulses, Volume Selective Excitation, Depth Resolved Spectroscopy.
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Fast Spoiled Grass Sequence with IR PreparationInfoSheet: - Sequences - 
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(IR-FSPGR) This sequence uses an inversion pulse followed by a spoiled low flip angle and short TR gradient echo train to collect all partition data. The 3D-IR-FSPGR uses centric ordering of Gz. The selected TI is also the effective TI. The centric reordering strategy can lead to image blurring if a steady state is not achieved quickly with low flip angles (less than 20°).
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