BRAIN TUMOR
Case Presentation
A 73-year-old man presented to his local emergency department after experiencing a generalized seizure. He had moderate left-sided weakness in the initial postictal period which quickly resolved. In retrospect, the patient had noted subjective left-hand “clumsiness” for a month prior to the seizure, but had not reported it to his family or physician.
Imaging Discussion
​While CT scans are often used first for glioblastoma, especially in emergencies, MRI scans provide more detailed and diagnostic information. Hence, MRI is the preferred method for a comprehensive diagnosis.
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On MRI scans, almost all glioblastomas react to gadolinium contrast, typically displaying a thick, uneven layer of tumor around a dead tissue cavity.
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Variations in signal strength and contrast enhancement within glioblastomas, as well as an irregular shape, are common.
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Increased permeability of blood vessels leads to surrounding swelling (vasogenic edema), which appears as a bright area on T2-weighted images.
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Hemorrhage can complicate glioblastoma imaging. Acute and early subacute hemorrhages appear less intense (darker) on T2 and vary in intensity on T1 images.
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This T1 hyperintensity (brightness) can mimic gadolinium enhancement. Thus, always compare postcontrast and precontrast T1 images for accurate assessment.
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What We Are Looking For ?
(A) Unenhanced CT shows there are abnormal area of the brain. (B) T2-weighted FLAIR, the abnormal area appears bright after fluid attenuation and shows the abnormal area, (C) Gradient echo T1-weighted, the abnormal area appears dark compared to normal areas. (D) post-gadolinium spin echo T1-weighted images depict a relatively circumscribed mass in the left superior temporal lobe with both solid, enhancing components and some cystic or necrotic areas. Moderate edema signal surrounds a portion of the mass.