SPONDYLODISCITIS - CLINICAL AND MAGNETIC-RESONANCE DIAGNOSIS

Study Design. This study reviews 65 patients with spondylodiscitis, bo th spontaneous and postoperative and of different etiology, studied by magnetic resonance imaging. Objectives. To define the magnetic resona nce imaging characteristics of infections of the spine in acute and ch ronic stages and to evaluate the role of magnetic resonance imaging in defining their etiology. Background Data. Early diagnosis of spondylo discitis is often difficult because of the long latent period, Radiogr aphs of the spine, bone scan, and computed tomography scan provide ins ufficient data. Methods. Among 65 patients with spondylodiscitis studi ed by magnetic resonance imaging, 24 were examined in the acute stage (clinical evolution between 7 days and 20 days), and 41 were examined in the chronic stage (3-6 weeks). The etiologic agent was staphylococc us in eight cases, Brucella in 13, Mycobacterium tuberculosis in 29, S almonella in four, and unknown in 11. Results. In cases observed in th e acute stage, the disc and the vertebral bodies were hypointense in T 1 and hyperintense in T2; this relatively constant finding was not cor related with the etiologic agent. In the chronic stage, cases caused b y Brucella or of unknown etiology showed long T1 and T2 relaxation tim es, with precocious contrast enhancement of the disc; in cases of tube rcular etiology there was slight shortening of T1, with inhomogeneous enhancement of the involved vertebral bodies and late disc enhancement . Conclusions. Magnetic resonance imaging is the investigation method of choice in diagnosing spondylodiscitis, especially in very early sta ges of the disorder, when other investigations still yield negative re sults. In chronic stages, magnetic resonance imaging also allows tuber cular spondylodiscitis to be distinguished from cases of different eti ology.