An 55 year old man presented with headache and left sided weakness.
Axial MRI scans: (Top) T1-weighted; (Bottom) T2-weighted. Note on T1, there is an abnormality that is mostly isointense / hypointense in the right posterior frontal lobe near the surface. The same area on T2 is dark with a surrounding bright signal. The dark signal on T1 and T2 represents deoxyhemoglobin whereas the isotense signal is oxyhemoglobin. The surrounding bright signal is vasogenic edema.
This is the characteristic picture of an acute hemorrhage changing to an acute (approximately 3 days old) hemorrhage on MRI. The findings of blood on MRI are complex and depend on timing. To learn more, review the powerpoint slide show, Blood on MRI: Time-dependent Changes. In this case, the hemorrhage was due to hypertension.
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