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A hyperintensity or T2 hyperintensity is an area of high intensity on types of magnetic resonance imaging (MRI) scans of the brain of a human or of another mammal that reflect lesions produced largely by demyelination and axonal loss.
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.
Myelomalacia is a pathological term referring to the softening of the spinal cord. [1] Possible causes of myelomalacia include cervical myelopathy, hemorrhagic infarction, or acute injury, such as that caused by intervertebral disc extrusion.
By carefully choosing the inversion time (TI), the signal from any particular tissue can be nulled. The appropriate TI depends on the tissue via the formula:
Either 1) brain MRI showing normal findings or only nonspecific white matter lesions, or 2) optic nerve MRI showing T2-hyperintensity, or T1 enhancing lesion, greater than 1/2 optic nerve length or involving optic chiasm Acute myelitis: intramedullary lesion > 3 contiguous segments, or spinal atrophy ≥ 3 contiguous segments
MRI is also highly sensitive to marrow abnormalities surrounding the fracture line, which appear as hypointensity on T1 W images and hyperintensity on fluid-sensitive sequences. Such signal changes are thought to be a combination of bone marrow edema, intraosseous haemorrhage, and/or granulation tissue and help to identify even undisplaced ...
On MRI, it usually shows hyper or iso-intensity on T1-weighted images and heterogenous hyperintensities on T2 weighted images. Pleural schwannoma typically shows fatty degeneration, hemorrhage, perivascular hyalinization, and cystic formation thus giving heterogenous hyperintensities on T2 weighted images.
T 2 *-weighted sequences are used to detect deoxygenated hemoglobin, methemoglobin, or hemosiderin in lesions and tissues. [2] Diseases with such patterns include intracranial hemorrhage, arteriovenous malformation, cavernoma, hemorrhage in a tumor, punctate hemorrhages in diffuse axonal injury, superficial siderosis, thrombosed aneurysm, phleboliths in vascular lesions, and some forms of ...