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The introduction of FLASH MRI sequences in diagnostic imaging for the first time allowed for a drastic shortening of the measuring times without a substantial loss in image quality. In addition, the measuring principle led to a broad range of completely new imaging modalities.
Phase contrast MRI (PC-MRI) is used to measure flow velocities in the body. It is used mainly to measure blood flow in the heart and throughout the body. PC-MRI may be considered a method of magnetic resonance velocimetry. Since modern PC-MRI typically is time-resolved, it also may be referred to as 4-D imaging (three spatial dimensions plus ...
It is named in contrast to T 1, the spin-lattice relaxation time. [ 2 ] T 1ρ MRI is an alternative to conventional T 1 and T 2 MRI by its use of a long-duration, low-power radio frequency referred to as spin-lock (SL) pulse applied to the magnetization in the transverse plane.
T1 weighted: T1: Measuring spin–lattice relaxation by using a short repetition time (TR) and echo time (TE). Lower signal for more water content, [1] as in edema, tumor, infarction, inflammation, infection, hyperacute or chronic hemorrhage. [2] High signal for fat [1] [2] High signal for paramagnetic substances, such as MRI contrast agents [2]
T1 weighted: T1: Measuring spin–lattice relaxation by using a short repetition time (TR) and echo time (TE). Lower signal for more water content, [67] as in edema, tumor, infarction, inflammation, infection, hyperacute or chronic hemorrhage. [68] High signal for fat [67] [68] High signal for paramagnetic substances, such as MRI contrast ...
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 ...
A contrast agent usually shortens, but in some instances increases, the value of T1 of nearby water protons thereby altering the contrast in the image. Most clinically used MRI contrast agents work by shortening the T1 relaxation time of protons inside tissues via interactions with the nearby contrast agent.
In MRI, T 2-weighted images can be obtained by selecting an echo time on the order of the various tissues' T 2 s. [8] In order to reduce the amount of T 1 information and therefore contamination in the image, excited spins are allowed to return to near- equilibrium on a T 1 scale before being excited again.