True regarding CSF on MRI:
Ans. bOption aFalseNo, all water containing structures are hypointense on T1W (CSF, edema, most pathologies, etc.)Option bTrueYes, all water containing structures are hyperintense on T2W (CSF, edema, most pathologies, etc.)Option cFalseFLuid Attenuated Inversion Recovery sequence--as the name suggests, all fluids appear blackOption dFalseNo, CSF does not show diffusion restriction and is thus, dark on diffusion- weighted imagingOption eFalseFree diffusion showing structures appear bright on ADC (apparent diffusion coefficient) mapsRef.: Fundamentals of Diagnostic Radiology. 3rd EditionMRI images are commonly viewed in three planes: axial, coronal, and sagittal.The routine MRI is presented as black and white images, not color. The various shades of gray are described in terms of their "signal intensity." "Low signal intensity" means "dark," and "high signal intensity" means "bright."MRI weighting: T1, T2, othersThe most commonly used techniques for MRI imaging are T1-weighted, T2-weighted, Flair and Diffusion-weighted.T1 weighted images are useful for brain parenchyma. Brain appears medium gray and CSF is dark gray, and air is nearly black. Most tumors appear dark, with low signal intensity. Fat has high signal intensity on T1 but "drops out" on T2 weighted images where it becomes dark. Gadolinium contrast added to the T1 may "light up" a tumor or abscess. If a lesion has dark signal on T1, and bright signal with gadolinium, it is a "contrast enhancing" lesion. The enhancement may be the same throughout the lesion, making it "homogeneously enhancing."T2 weighted images are great to evaluate CSF spaces, which appear bright white. Brain appears light gray. Use the T2 sequence to check the size and symmetry of the ventricles, and look for bright signal of edema surrounding an aggressive tumor or a subacute stroke or hemorrhage. The T2 images accentuate high-water-content tissue by making it look white (hyperintense) on MRI.The flair sequence is "a T2 with dark CSF," very sensitive to edema and to parenchymal abnormalities like a low grade glioma.Diffusion weighted images have one purpose: to visualize an area of acute ischemia.Remember: An MRI is the study of choice for tumor, multiple sclerosis, and ischemic stroke. Add gadolinium contrast to evaluate tumor and abscess. For brain hemorrhage, however, CT is the go-to study.
Hyper-intense on T1 W
Hyper-intense on T2 W
Hyper-intense on FLAIR
Hyper-intense on DWI
Nervous System