"radiology" Post in this tag
high signal in diffusion weighted imaging
ischemic stroke
brain abscess(ring enhancementが見られた時にglioblastoma, brain metastasisから鑑別のためにDWI用いる)
膿は拡散が低下するので高信号
radiology
HirotoShishido
low intensity in T2WI
iron(hemosiderin=chronic hemorrhage), dioxyhemoglobin(acute hemorrhage),
calcification(CT is more sensitive), high protein, melanin, flow void
radiology
HirotoShishido
low intensity in both T1WI, T2WI
air, bone cortex, flow void
(calcification, iron, fibrosis)
radiology
HirotoShishido
T1WI T2WI high intensity
T1→ ☆fat, ☆high protein(posterior pituitary), ☆methemoglobin(subacute hemorrhage),
melanin(melanoma), paramagnetic cation(kˈætὰɪən)(Mn, Gd→basal ganglia, contrast media)
T2→ fat, methemoglobin, water(,edema, tumor)
radiology
HirotoShishido
chest X-ray, CT effective radiation dose
natural background radiation
chest X-ray 0.1mSv
CT(abdomin,pelvis) 10mSv
natural 2.5mSv/year (world average)
radiology
HirotoShishido