18 F-FDG PET/CT Imaging in Pyogenic and Tuberculous Spondylitis

INTRODUCTION: The detection or differential diagnosis of spinal infections is sometimes difficult despite the availability of advanced diagnostic technology. Although Jung et al concluded that MRI is accurate for differentiating tuberculous spondylitis from pyogenic spondylitis, ambiguous cases are often encountered in daily clinical practice. Moreover, there are often patients who are unable to undergo an immediate biopsy or surgery. Recently, positron emission tomography (PET) with fluorodeoxyglucose (FDG) has been used increasingly to detect suspected infections. Fluorine18 (18F) FDG PET has demonstrated high sensitivity and specificity for detecting and identifying the processes of inflammatory activity in spondylitis. Gratz et al suggested that FDG hybrid PET can help to correctly identify those patients with vertebral osteomyelitis. It assists in differentiating between mild infections and degenerative changes, detects additional manifestations outside the spine in a substantial number of patients, and shows a good correlation with the histological severity of the infection. In particular, a combined PET/CT study can provide a synergistic combination of PET and CT, which is potentially more valuable than performing the two examinations separately. To our knowledge, there is little clinical experience in the field of PET/CT imaging for distinguishing between pyogenic and tuberculous infections. Therefore, this study evaluated the usefulness of 18F-FDG PET/CT for differentiating between tuberculous and pyogenic spondylitis and compared it with the diagnostic performance of MRI.