Ageing blood on MRI is dependent on the varying MRI signal characteristics of haemorrhagic collections with time and can be very useful in correlating the imaging findings with the clinical picture. However, as it can be complicated to recall the MRI features of ageing blood through the 5 stages of haematoma evolution, several mnemonics have been devised:
I Be, IdDy, BiDy, BaBy, Doo Doo
I Bleed, I Die, Bleed Die, Bleed Bleed, Die Die
I BID BaD BaBy DO
I Bleed, I Die, But Department Boss Bleeds, Department Dies
Mnemonics
The first two mnemonics use the first letters of the words and word pairs to denote the signal characteristics of blood at each stage as isointense (I), bright (B), or dark (D). The first bold letter in each pair denotes the typical T1 signal finding, while the second denotes the T2 signal change.
-
I Be
T1 Isointense
T2 Bright
hyperacute <1 day
-
IdDy
T1 Isointense
T2 Dark
acute 1 to 3 days
-
BiDy
T1 Bright
T2 Dark
early subacute 2 to 7 days
-
BaBy
T1 Bright
T2 Bright
late subacute 7 to 14-28 days
-
Doo Doo
T1 Dark
T2 Dark
chronic >14 to 28 days
For those that find it difficult to memorise the mnemonic above an alternative is found below which uses full word pairs.
-
I Bleed
T1 Isointense
T2 Bright
hyperacute <1 day
-
I Die
T1 Isointense
T2 Dark
acute 1 to 3 days
-
Bleed Die
T1 Bright
T2 Dark
early subacute 2 to 7 days
-
Bleed Bleed
T1 Bright
T2 Bright
late subacute 7 to 14-28 days
-
Die Die
T1 Dark
T2 Dark
chronic >14 to 28 days
This mnemonic uses bold capital letters of the sentence in pairs to denote the signal characteristics of blood at each stage as isointense (I), bright (B), or dark (D). The first bold letter in each pair denotes the typical T1 signal finding while the second bold letter denotes the T2 signal change.
-
I B
T1 Isointense
T2 Bright
hyperacute <1 day
-
I D
T1 Isointense
T2 Dark
acute 1 to 3 days
-
BaD
T1 Bright
T2 Dark
early subacute 2 to 7 days
-
BaBy
T1 Bright
T2 Bright
late subacute 7 to 14-28 days
-
DO
T1 Dark
T2 dark (O represents the haemosiderin ring)
chronic >14 to 28 days
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