MRI brain sequences are important for neurologists and medical students.
A pulse sequence in MRI consists of a radio frequency component and an acquisition phase.
Contrast in MRI images is obtained from the different rates of relaxation of protons in different tissues.
β‘οΈ T1 and T2 are MRI sequences with different signal intensities for water, fat, and contrast.
π§ T1 images show bright fat, dark water, and are useful for anatomic details and vascular changes.
π‘ T2 images show bright water, dark fat, and are useful for identifying pathology and lesions.
π§ MRI sequences like T1, T2, Flair, and DWI have distinct characteristics and applications.
πΌοΈ T1 sequence shows fat as bright and CSF as dark, while T2 sequence shows fat as dark and CSF as bright.
π‘ Flair sequence is similar to T2, but with flipped CSF spaces.
π Flair does a better job of delineating lesions near the ventricles and can distinguish edema from CSF.
π§ Flair is useful for gray-white differentiation, especially in structures like the putamen and the head of the caudate.
π‘ Flair and T2 images are similar, but the CSF spaces are inverted in Flair.
π Susceptibility weighted imaging or T2 star can detect metals like blood and calcium in the brain.
π©Έ GRE is useful for detecting early and old hemorrhages, including hemosiderin deposition.
π§ T1 sequence can be used to identify myelin, while CSF appears dark.
β‘οΈ DWI, or diffusion-weighted imaging, is crucial for detecting strokes.
π DWI is a fast MRI sequence that measures the movement of water molecules in the extracellular space.
β‘οΈ Cytotoxic edema causes fluid restriction in the affected area, leading to hyperintensity on DWI images.
π§ The presence of hyperintensity on DWI images may indicate an ischemic stroke.
π§ The T2 image can sometimes create false ischemia due to high intensity areas.
π‘ ADC fluid restriction can be used to rule out certain conditions.
π DWI and ADC sequences provide different brightness levels for imaging.
The Impact of chatGPT talks (2023) - Prof. Max Tegmark (MIT)
Jordan Peterson: The Development of Aggressive Children
I found "the truth" in these 7 ancient books.
How to parent a teen from a teenβs perspective | Lucy Androski | TEDxYouth@Okoboji
The Power of a Teacher | Adam Saenz | TEDxYale
Profiling and PWH Purge Issues