View source for Estimate age of hemorrhage - MRI

{| class="wikitable"
|-
! Stage !! Biochemistry !! Location !! Property !! T1W !! T2W !! Mnemonic
|-
| Hyperacute (hrs) || oxy-Hb || intracellular || Dimagnetic || isointense || <span style="color:red"> bright</span>|| IB
|-
|Acute (1-2 days) || deoxy-Hb||intracellular||paramagnetic||isointense||dark||ID
|-
|Early subacute (2-7 days)||Met-Hb||intracellular||paramagnetic||<span style="color:red">bright</span>||dark||BD
|-
|Late subacute (1-4 wks)||Met-Hb||extracellular||paramagnetic||<span style="color:red">bright</span>||<span style="color:red">bright</span>||BaBy
|-
|Chronic||Hemosiderin||extracellular||ferromagnetic||dark||dark rim||DooDoo
|}


* Appearance of intracranial hemorrhage on MR depends on the age of the hematoma and the sequence (Tl or T2 weighted). 
* As hematoma ages, hemoglobin passes through different forms (oxyhemoglobin à deoxyhemoglobin à methemoglobin) prior to red cell lysis and breakdown into hemosiderin.

{| class="wikitable"
|-
!Mnemonic!!Stage!!T1!!T2
|-
|'''I'''t '''B'''e||Hyperacute||isointense '''(I)'''||hyperintense '''(B)'''
|-
|'''I'''d'''D'''y||Acute||iso to hypointense '''(I)'''||hypointense '''(D)'''
|-
|'''B'''i'''D'''dy||Early Subacute||hyperintense '''(B)'''||hypointense '''(D)'''
|-
|'''B'''a'''B'''y||Late Subacute||hyperintense '''(B)'''||hyperintense '''(B)'''
|-
|'''D'''oo '''D'''oo||Chronic||hypointense '''(D)'''||hypointense '''(D)'''
|}