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A hyperintensity or T2 hyperintensity is an area of high ... on an MRI image and the term "bright signal" is occasionally used as a synonym for a hyperintensity.
T2*-weighted imaging of the brain 26 weeks after subarachnoid hemorrhage, showing hemosiderin deposits as hypointense areas. [1] T 2 *-weighted imaging is an MRI sequence to quantify observable or effective T 2 (T2* or "T2-star"). In this sequence, hemorrhages and hemosiderin deposits become hypointense. [2]
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.
The term "leukoaraiosis" was coined in 1986 [6] [7] by Hachinski, Potter, and Merskey as a descriptive term for rarefaction ("araiosis") of the white matter, showing up as decreased density on CT and increased signal intensity on T2/FLAIR sequences (white matter hyperintensities) performed as part of MRI brain scans.
For example, it can be used in brain imaging to suppress cerebrospinal fluid (CSF) effects on the image, so as to bring out the periventricular hyperintense lesions, such as multiple sclerosis (MS) plaques. [1] It was invented by Graeme Bydder, Joseph Hajnal, and Ian Young in the early 1990s. [2]
Posterior reversible encephalopathy syndrome; Other names: Reversible posterior leukoencephalopathy syndrome (RPLS) Posterior reversible encephalopathy syndrome visible on magnetic resonance imaging as multiple cortico-subcortical areas of T2-weighted hyperintense (white) signal involving the occipital and parietal lobes bilaterally and pons.
High signal for paramagnetic substances, such as MRI contrast agents [5] Standard foundation and comparison for other sequences T2 weighted: T2: Measuring spin–spin relaxation by using long TR and TE times Higher signal for more water content [4] Low signal for fat in standard Spine Echo (SE), [4] though not with Fast Spin Echo/Turbo Spin ...
At the end, images are "weighted" by the diffusion process: In those diffusion-weighted images (DWI) the signal is more attenuated the faster the diffusion and the larger the b factor is. However, those diffusion-weighted images are still also sensitive to T1 and T2 relaxivity contrast, which can sometimes be confusing.