Modic changes are MRI signal intensity changes in vertebral body marrow adjacent to the endplates of degenerative discs.
These changes were described by Michael T. Modic, MD, professor of radiology and neurology from USA.
Three types:
Type I-
- Hypointense on T1, hyperintense on T2
- Pathology - replacement with fibrovascular marrow / edema
- Microscopic features - Spindle cells, capillaries (vascularised fibrous tissue), prominent trabeculae with new bone formation
- Incidence - 4 %
- Associated with an acute process
Type II-
- Hyperintense on T1, isointense on T2
- Pathology - replacement with fatty marrow
- Microscopic features - Adipose cells, prominent trabeculae
- Incidence - 16 %, most common type
- Associated with a chronic process
Type III-
- Hypointense on T1 and T2
- Pathology - replacement with bony sclerosis, little residual marrow
- Microscopic features - Dense woven bone
- Incidence - 1 %, least common type
- Correlates with sclerosis seen on plain films
Modic changes are more common in lumbar spine, but may occur at any vertebral level.
Size: Varies from small linear bands to involvement of entire end plate
Associated abnormalities: Loss of disc space height and loss of signal from disc on T2WI
Natural history: Type I change may convert to type II over a span of few years. Type II change is more stable.