The penumbra sign in subacute osteomyelitis


The penumbra sign is a characteristic magnetic resonance (MR) feature of subacute osteomyelitis. It can be identified on unenhanced T1-weighted spin echo images as a discrete peripheral zone of marginally higher signal intensity than the central bony abscess cavity and the surrounding lower signal intensity of the reactive new bone and oedema.

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Correspondence to A. M. Davies.

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Davies, A.M., Grimer, R. The penumbra sign in subacute osteomyelitis. Eur Radiol 15, 1268–1270 (2005).

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  • Osteomyelitis
  • Magnetic resonance imaging
  • Bone sarcoma