The Four MRI Layers of Subacute Osteomyelitis (Brodie’s Abscess):
-
Inner core of pus and necrotic tissue. High T2, low T1 signal intensity and no enhancement.
-
Thin layer of granulation tissue. Intermediate to high T1 and low T2 signal intensity with contrast enhancement. Known as the “penumbra sign” and highly specific for Brodie’s.
-
Thin layer of fibrosis and sclerosis. Low T1 and T2 signal intensity. No contrast enhancement.
-
Thick outer layer of reactive edema. Low T1 and high T2 signal intensity. Variable patchy enhancement.
Images are T1 Fat Sat PG
