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An MRI pulse sequence in magnetic resonance imaging (MRI) is a particular setting of pulse sequences and pulsed field gradients, resulting in a particular image appearance. [ 1 ] A multiparametric MRI is a combination of two or more sequences, and/or including other specialized MRI configurations such as spectroscopy .
Standard foundation and comparison for other sequences Proton density weighted: PD: Long TR (to reduce T1) and short TE (to minimize T2). [4] Joint disease and injury. [5] High signal from meniscus tears. [6] (pictured) Gradient echo (GRE) Steady-state free precession: SSFP: Maintenance of a steady, residual transverse magnetisation over ...
Modern 3 Tesla clinical MRI scanner.. Magnetic resonance imaging (MRI) is a medical imaging technique mostly used in radiology and nuclear medicine in order to investigate the anatomy and physiology of the body, and to detect pathologies including tumors, inflammation, neurological conditions such as stroke, disorders of muscles and joints, and abnormalities in the heart and blood vessels ...
The thin bar denotes a 90° pulse, while the thick bar denotes a 180° pulse. INEPT is a common building block of NMR experiments to improve 15 N signal. [1] In Fourier transform NMR spectroscopy and imaging, a pulse sequence describes a series of radio frequency pulses applied to the sample, such that the free induction decay is related
Susceptibility weighted imaging (SWI), originally called BOLD venographic imaging, is an MRI sequence that is exquisitely sensitive to venous blood, hemorrhage and iron storage. SWI uses a fully flow compensated, long echo, gradient recalled echo (GRE) pulse sequence to acquire images.
Thus MR pulse sequences sensitive to T 2 * show more MR signal where blood is highly oxygenated and less where it is not. This effect increases with the square of the strength of the magnetic field. The fMRI signal hence needs both a strong magnetic field (1.5 T or higher) and a pulse sequence such as EPI, which is sensitive to T 2 * contrast. [23]
Fluid-attenuated inversion recovery (FLAIR) [2] is an inversion-recovery pulse sequence used to nullify the signal from fluids. For example, it can be used in brain imaging to suppress cerebrospinal fluid so as to bring out periventricular hyperintense lesions, such as multiple sclerosis plaques.
Equation for calculating the slew rate and accompanying diagram. In general, real time MRI relies on gradient echo sequences, efficient k-space sampling, and fast reconstruction methods to speed up the image acquisition process. [11] Gradient echo sequences present shorter echo times since only one RF pulse is required for each sequence. [12]