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. 305 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.