Early diagnosis of spinal tuberculosis by MRI.

MRI was performed at three centres in Bombay on 24 patients clinically suspected of tuberculosis of the spine but with normal radiographs. There were 11 males and 13 females and their average age was 24 years (11 to 60). 99mTc bone scans were done in 16 patients before MRI. Eleven patients had the diagnosis confirmed by biopsy and the remainder all responded rapidly to specific antituberculous chemotherapy. On T1-weighted images there was a decrease in signal intensity of the involved bone and soft tissues; on T2-weighted images there was increased signal intensity. Depending on the stage of the disease, three different patterns of infection were revealed: osteitis, osteitis with an abscess, and osteitis with or without an abscess plus discitis. The anatomical pattern of involvement, particularly of the soft tissues and the discs, is specific for tuberculous disease. The ability of MRI to detect tuberculosis of the spine earlier than other techniques could reduce bone destruction and deformity and diminish the need for surgical intervention. Despite the specificity of the patterns revealed by MRI, biopsy is recommended during the stage of osteitis to confirm the diagnosis.