-extending from l1-l3 there is a shallow intermediate/low t1 signal, high t2 signal collection in the anterior epidural space. compressing the cord.
-prominent high fluid signal with widening of the left l3/l4 facet with a paraspinal collection-septic facet joint.
-subacute resolving l5/s1 discitis-not much endplate irregularity.
–Spinal epidural abscess represents infection of the epidural space, located between the spinal dura mater and the vertebral periosteum. I
Spinal epidural abscesses develop from direct spread from neighbouring structures and are, unsurprisingly, usually adjacent to the primary focus. discitis-osteomyelitis which is thought to be the primary source of infection in up to 80% of patients 3, usually results in anterior abscesses 4. In contrast, when facet joint septic arthritis is the primary infection, collections tend to be posterior or posterolateral. This is the same distribution as what are believed to be cases resulting from a direct haematogenous spread, which is primarily located in the posterior/dorsal aspect of the spinal canal 4.
for spinal epidrual infection, usually need a contrast mri as the abscess tends to have two stages
1. phlegmonous stage of infection results in a homogeneous enhancement of the abnormal area which correlates to granulomatous-thickened tissue with embedded micro-abscess without a significant pus collection- so phlegmon is solid enhancing soft tissue mass-thick granulation tissue.
2. liquid abscess surrounded by inflammatory tissue which shows a varying degree of peripheral enhancement with gadolinium
The key to identifying liquid abscesses, which is usually a sufficient cause for surgical drainage, is the presence of a region of high T2 signal, with low T1 signal and without enhancement (usually surrounded by a rim of enhancement). DWI/ADC commonly demonstrates restricted diffusion of the abscess content.