A 63 year old man was in an automobile accident. He was in coma at the seen.
(Left) Axial CT scan' (Middle) T1-weighted; (Right) T2-weighted. Note on the CT that the intracerebral hemorrhage in the frontal lobes is quite obvious. However, on the MRI scans, hyperacute blood is much more difficult to recognize. On T1, there is an abnormality that is relatively isointense to slightly hypointense The same area on T2 is isointense / hyperintense with a surrounding bright signal. This is the characteristic picture of a hyperacute (approximately 1 day old) hemorrhage on MRI. In the hyperacute stage, intracellular oxyhemoglobin is isointense / hypointense on T1 and isointense / hyperintense on T2. 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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