Spondylodiscitis can mimic many other pathologies,
such as degenerative intervertebral disease ,
inflammatory spondyloarthropathies,
neoplasms and compression fractures.
These noninfectious conditions may simulate a spondylodiscitis by showing similar features.
It is helpful to be aware of these diseases and their MR imaging features.
If endplate destruction,
increased disk signal intensity on T2WI,
enhancement after contrast,
or paravertebral or epidural abscess is present,
infectious spondylitis,
rather than Modic type 1 degeneration,
should be suspected.
(3)
To distinguish tumor involvement: posterior elements and non-contiguous vertebral bodies may be affected.
The intervertebral disk is usually respected (most useful to exclude).
Both can associate parapinal / epidural mass and vertebral bone destruction.
Infection of an isolated vertebral body is a atypical feature thought to represent an early manifestation of a spinal infection.
Atypical patterns of spinal infection include:
-Involvement of only one vertebral body ,
one vertebral body and one disk ,
and two vertebral bodies without the intervening disc(3)
-Height of the disk may not be diminished or even increase -if there is an intradiskal abscess - or it may be only in appearance if there is collapse of the adjacent vertebral bodies.
-In early stages the disk can be isointense or hypointense in T2.
-Very rarely the disk may not enhance.
The absence of typical findings or the presence of atypical findings in MRI does not exclude the possibility of spondylodiscitis.
Radiological signs of MRI are more useful for early diagnosis,
since in the initial phases clinically it can be insidious and less expressive.
Detection and treatment of spondylodiscitis prevent future situations of disability: chronic pain,
instability and vertebral collapse,
neuropathy / compressive myelopathy,
...
The initial radiological findings of spondylodiscitis can be difficult to distinguish from the radiological findings of vertebral osteonecrosis,
especially if there is vertebral collapse,
both entities require specific treatment that can not be postponed to avoid subsequent sequelae.
Vertebral osteonecrosis is an uncommon disease that occurs mostly in patients with a collapsed vertebral body,
due to the rich vascularization of the vertebral body(11).
It is thought to be the consequence of insult at the anterior segment of the vertebral body,
with possible mechanisms being either traumatic (called Kummel disease and represents delayed vertebral collapse after major trauma ) or nontraumatic, involves repeated microtrabecular fractures in a vertebral body that is weakened because of osteoporosis,
replacement of marrow by abnormal cells,
or long-term administration of glucocorticoids.
(11).
However as our population ages,
the prevalence of osteoporosis,
vertebral compression fracture and osteonecrosis vertebral will increase.
Studies are increasingly on older patients affected by osteoporosis,
so the probability of this finding can be not so uncommon.
It may be a potential complication in up to one-third of vertebral compression fractures.
(12).
The distinct radiographic findings (intervertebral air,
pseudarthrosis,
and normal adjacent levels),
which reliably differentiate this condition from
more morbid ones like spondylodiscitis.