Spinal tuberculosis: CT and MRI features

BACKGROUND: Spinal tuberculosis (TB) is perhaps the most clinically important extrapulmonary form of the disease. Early recognition is therefore necessary to minimize residual spinal deformity and/or permanent neurological deficit. We defined the CT and MRI image morphology of spinal TB and correlated the imaging features of these two modalities. METHODS: CT (29 patients) and MRI (11 patients) images were retrospectively analyzed in 30 patients with proved spinal TB. CT and MRI findings were compared in cases with both imaging tests (10 cases). The parameters assessed were the type and extent of bone and soft tissue involvement. RESULTS: The majority of the 30 patients were males (n=18) in the 30-49 year age group (43%). The most common clinical presentation was backache (73.3%) followed by fever (63.3%) and malaise (36.6%). The lumbar spine was the commonest site of the disease (43.3%) followed by the thoracic region (36.6%). A fragmentary type of bone destruction was the most frequent CT feature of the disease (48.2%) followed by the lytic type (24.1%). Intervertebral disc destruction (72%) and paravertebral mass/abscess (65.5%) were other features. Of the 11 patients who had an MRI, contiguous vertebral disease with disc destruction was seen in 10 cases. In 4 patients, there was distant vertebral disease in addition to the disease at the symptomatic site. CONCLUSIONS: MRI offers excellent visualization of the bone and soft tissue components of spinal tuberculosis and helps to identify disease at distant asymptomatic sites. CT is useful in assessing bone destruction, but is less accurate in defining the epidural extension of the disease and therefore its effect on neural structures. MR imaging clearly demonstrated the extent of soft tissue disease and its effect on the theca/cord and foramen in cases with doubtful CT findings.