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.
Davies
A M
AM
Department of Radiology, NHS Trust, MRI Centre, Royal Orthopaedic Hospital, Birmingham, UK. wendy.turner@roh.nhs.uk
Grimer
Robert
R
D000208:Acute Disease; D003937:Diagnosis, Differential; D006801:Humans; D008279:Magnetic Resonance Imaging; D010019:Osteomyelitis / Q000175:diagnosis*