Acute Intracerebral Hemorrhage - Case 7

A 52 year-old man with known metastatic melanoma presented with an acute headache and left sided weakness.


Note the Dark Signal on T1     Note the Early Bright Rim on T1     Note the Dark Signal on T2

Acute Intracerebral Hemorrhage: (Left) T1-weighted axial MRI; (Right) T2-weighted axial MRI. Note that on the T1-weighted scan, there is an abnormality in the right posterior frontal and parietal lobes that is dark. The same area on the T2-weighted scan is also dark with a surrounding bright signal.

This is the characteristic picture of an acute (approximately 3 days old) hemorrhage on MRI. In the acute stage, intracellular deoxyhemoglobin is dark on both T1- and T2-weighted scans. As the deoxyhemoglobin changes to intracellualr methemoglobin, the signal becomes bright on T1-weighted scans but remains dark on T2-weighted scans. If one looks closely at the T1-weighted scan, there is a faint rim of bright signal. This represents the early formation of methemoglobin. In this case, the patient presumably bled into a small metastatic lesion.

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.

Revised 11/29/06.
Copyrighted 2006. David C Preston.