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

Chondral injury Grading in MRI

MRI grading for chondral injury = modified Outerbridge classficiation + Noyes system 

Grade 0	Normal. Intact cartilage
Grade 1	Abnormal chondral signal intensity (oedema)	MRI Grade 1 chondral injury
Grade 2	Superficial defects (fraying, fissuring, ulceration or erosion) with <50% thickness involved	MRI Grade 2 chondral injury
Grade 3	Defects with >50%, <100% thickness involved	MRI Grade 3 chondral injury
Grade 4	Full thickness defect	MRI Grade 4 chondral injury

MRI Grade 1 Chondral injury. Notice the increased signal intensity?

MRI Grade 2 Chondral injury. Notice the chondral thinning?

        

MRI Grade 3 Chondral injury. Notice the deep chondral fissuring?

MRI Grade 4 Chondral injury. Full thickness defects in both tibia and femur