Epidural abscess

Case contributed by Dr Bruno Di Muzio


IVDU, septic, and with diffuse back pain.

Patient Data

Age: 30 years

Whole spine

There is an extensive epidural collection, which is predominantly posterior in distribution, tracking down from the T1 until the L3/4 levels, and demonstrating peripheral thick rim enhancement consistent with an abscess. It causes moderate canal stenosis, predominantly at the mid and lower thoracic levels, and compresses against the cord. No cord signal abnormality is confidently identified. At the cervical spine, there is some posterior epidural enhancing phlegmon from C3 to T1, but without convincing fluid collection. There is left L2/3 facet joint rim-enhancing collection tracking to the adjacent paraspinal muscles from L1 to L3. This inflammatory process causes adjacent facets bone barrow signal changes inferring osteomyelitis. There is enhancement of the right L2/3 synovium compatible with septic arthritis. Edema and wispy enhancement within the left psoas muscle compatible with myositis. Left sacroiliac joint has increased fluid and peripheral irregular thick enhancement consistent with sacroilitis/osteomyelitis. Enhancing phlegmon extends into the epidural space through the left S1/2 foramen, and also partially involves the adjacent psoas, iliacus and gluteal muscles, but no discrete soft tissue collections identified at this region. Enhancing phlegmon seen within the left presacral soft tissues. The opposed endplates of T5/6 demonstrate Schmorl nodes and surrounding marrow edema that is felt to be related to degenerative changes (acute Schmorl nodes) rather than infective. The intervertebral discs have otherwise normal signal, with no convincing signs of diskitis. Patchy left pulmonary lower lobe air spaces opacities are concerning for infection. 



DWI/ADC performed together with the remainder sequences depicts diffusion restriction within the epidural collection, consistent with an abscess.

Case Discussion

This patient has multiple infective foci due to haematogenous seeding related to the use of intravascular drugs: extensive epidural abscess extending from T1 until the L3/4 levels with associated epidural phlegmon extending further beyond these levels. Also, left L2/3 facet joint septic arthritis/osteomyelitis, right L2/3 septic arthritis, left sacroiliitis/osteomyelitis, and left lung infective changes. Paraspinal, left iliopsoas and gluteal myositis/phlegmon. 

An urgent surgical review is mandatory in cases like this one. This patient went to theater about two hours after this scan, and three posterior laminectomies with epidural drain insertion were performed. 

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Case information

rID: 57029
Published: 10th Mar 2018
Last edited: 11th May 2020
Inclusion in quiz mode: Included

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