Monday, November 7, 2011

Modic changes in MRI


Modic classification

Use for different endplate marrow degenerative changes (which is postulated to result from same pathological process, but at different stages) in lumbar spine MR imaging.

Modic degenerative changes often accompanies disk degenerative disease (DDD)


The Modic change can be of mix type 1 and 2, type 2 and 3.

Modic type
T1w
T2w
Pathology
1
(oedema)
Hypointense


Hyperintense

Modic1. Note also disk dessication.

Oedema & Inflammation
2
(fat)
Hyperintense


Iso/Slight Hyperintense

Modic2. Note also disk dessication.

Marrow ischaemia, thus red marrow converts to fatty yellow marrow
3
(sclerosis)
Hypointense


Hypointense

Modic3. Note also disk dessication.

Subchondral sclerosis

Radiograph of the same patient with Modic 3 degeneration. Note sclerosis (arrow).


Note:
Disciitis can mimic Modic 1 degenerative change, when the adjacent bone marrows from the inflamed/infected disk is inflamed

Look at 3 things:
(1) Whether the intervertebral disk shows corresponding degenerative change (disk dessication) or shows inflammed (disciitis)

(2) Whether the bone or adjacent structures points to infection eg bone erosion, abscess formation

(3) Last but not least, correlate clinically - Lab changes, Clinical history



Endplates
Intervertebral disk
Others
Modic 1
Low T1w, High T2w
Iso/Low T2w

Usually dessicated (modic change accompanies disk degenerative disease)

Clinically non-toxic
Diskiitis
Same as above, but with features of diskiitis ie bone erosion
High T2w

Inflammed disk
Presence of inflammation / abscess in adjacent structures (eg paraspinal, epidural abscess)

Clinical and laboratory findings of infection