eRadiograph Volume 7: Imaging of Oral Cavity | Page 305
A differentiation between metastases and infection is generally infection is centered
on end plates and involves the disk spaces. Metastases is centered on the vertebral
body and posterior elements.
Chordoma
These arise from notochord remanants centered on the vertebral body extending to
discs, prevertebral space, epidural space, adjacent vertebrae - typical locations are at
the sacrococcygeal and spheooccipital locations. They may occur in the vertebral
bodies and when they occur usually involving C2. They appear as a midline destructive
mass which is T2 hyperin-tense, they may have internal septae.
Osteochondroma
These may be sessile or pedunculated. The vertebral column is an uncommon location
compromising of less than 5% of cases. These have a cauliflower appearance and are
contiguous with the medullary cavity of the vertebral body. Osteochondromas
resemble marrow signal intensity and have a cartilaginous cap. This is hypointense on
T1 and hyperintense on T2WI. During skeletal development this section demonstrates
growth. After skeletal maturity a cartilaginous cap of more than 1.5 cm or showing
rapid growth may indicate potential malignant degeneration into a chondrosarcoma.
Chondrosarcomas – Destructive lytic lesions in posterior elements (40%) vertebral
body (15%) both (45%).
The internal contents are of multiple cystic locules with fluid/fluid levels with
sedimentation of blood products. A mimic of ABC is telangiectatic osteogenic
sarcoma which is more aggressive than ABC thus manages differently. They appear
similar on imaging however osteogenic sarcoma is more aggressive, there is more bone
destruction and soft tissue infiltration.
Giant Cell Tumor
This is also an expansile lytic lesion that occurs in a mature skeleton. These are usually
centered in the vertebral body though posterior element involvement also occurs.
There is also often extraosseous soft tissue extension. They are heterogeneous in signal
intensity though demonstrate T2 hyperintensity due to chondroid components in the
tumor. 10 – 15% of GCT have an ABC component 10% turn sarcomatous.
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Perivertebral Space
Aneurysmal Bone Cyst
These are benign expansile multiloculated cystic lesions with a predilection from spinal
posterior elements they also commonly extend into the vertebral bodies as well as
extend into the PVS and peidural spaces.