There are a couple of mnemonics to age intracranial hemorrhage on MRI:

IdDy
BiDdy
BaBy
DooDy

where I=Isointense, D=Dark, B=Bright as compared to normal brain and therefore:

.............................T1.....T2

Acute (hour)............I...... D
Subacute (days)......B.......D
Subacute (weeks)....B.......B
Chronic (months).....D......D

The other is simpler but remember George Washington Bridge for T1 (Gray, White, Black) and an Oreo cookie for T2 (Black/White/Black).

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mpp - 15 October 2006 07:33 PM

There are a couple of mnemonics to age intracranial hemorrhage on MRI:

IdDy
BiDdy
BaBy
DooDy

where I=Isointense, D=Dark, B=Bright as compared to normal brain and therefore:

.............................T1.....T2

Acute (hour)............I...... D
Subacute (days)......B.......D
Subacute (weeks)....B.......B
Chronic (months).....D......D




The other is simpler but remember George Washington Bridge for T1 (Gray, White, Black) and an Oreo cookie for T2 (Black/White/Black).

The imaging characteristics of blood on MRI are variable and change with the age of the blood.

In general 5 stages of haematoma evolution are recognised:

1. hyperacute
* intracellular oxyhaemoglobin
* isodense on both T1 and T2
2. acute (1 to 2 days)
* intracellular deoxyhaemoglobin
* T2 signal intensity drops (T2 shortening)
* T1 remains intermediate to long
3. early subacute (2 to 7 days)
* intracellular met-haemoglobin
* T1 signal gradually increases (T1 shortening) to become hyperintense
4. late subacute (7 to 14-28 days)
* extracellular met-haemoglobin: over the next few weeks - as cells break down, extracellular met haemoglobin lead to an increase in T2 signal also
5. chronic (>14-28 days)
* periphery
o intracellular haemosiderin
o low on both T1 and T2
* center
o extracellular hemichromes
o isointense T1, hyperintense T2

from the Neurosurgery Survival Guide on the iPhone