Literature review of: The role of magnetic resonance imaging in the imaging diagnosis of spondylodiscitis

Abstract

Infection that affects the intervertebral disc and contiguous vertebrae is called spondylodiscitis or spondylitis. Some authors report that the terms discitis, spondyloarthritis, inflammation\ infection of the intervertebral disc space, benign vertebral osteomyelitis, nonspecific spondylitis, and pyogenic vertebral osteomyelitis refer to the same infection. Spondylodiscitis accounts for 2%-4% of all cases of skeletal infections. Its rapid diagnosis and appropriate treatment can avoid complications such as spinal cord compression, vertebral collapses, avoiding surgery. Its diagnosis is based on characteristic clinical and radiological findings, and is confirmed by biopsy of the disc or vertebra and blood cultures. Regarding the etiology, spondylodiscitis can be pyogenic, caused by several types of bacteria, or granulomatous, caused by mycobacteria, Brucella, spirochetes or fungi. The most prevalent spondylodiscitis are pyogenic and those associated with tuberculosis infection.

In pyogenic spondylodiscitis, the lumbar spine is the most involved segment, followed by the dorsal and, less commonly, the cervical and sacral columns. The spine is the most common site of tuberculosis infection in the musculoskeletal system (about 50% of cases), with the low dorsal spine and the lumbar spine the most affected. The main signs suggestive of pyogenic spondylodiscitis are: segmental involvement; abscesses with poorly defined boundaries; early involvement of the intervertebral disc; homogeneous involvement of the vertebral bodies and intervertebral discs, while those of tuberculous spondylodiscitis are: abscess of thin and well-defined walls; multisegmental subligament involvement; heterogeneous involvement of the vertebral bodies; intervertebral discs relatively spared. The objective of this literature review is to present the main aspects of spondylodiscitis on magnetic resonance imaging.