The use of MRI, PET/CT, and nuclear scintigraphy in the imaging of pyogenic native vertebral osteomyelitis: a systematic review and meta-analysis

Background Context: Native vertebral osteomyelitis (NVO) is a severe infection with an increasing incidence globally. Although there is no widely agreed upon reference standard for diagnosis of the disease, imaging plays a crucial role. Magnetic resonance imaging (MRI) is currently the imaging modality of choice. In recent years, advances in imaging have allowed for a larger role for alternative imaging techniques in the setting of NVO. Purpose: Our aim was to evaluate the diagnostic accuracy of MRI, PET/CT, and nuclear imaging, namely ⁶⁷Gallium and ^99mTechnetium scintigraphy, in the diagnosis of pyogenic NVO. Study Design/Setting: We conducted a systematic review of five medical databases and included all studies from 1970 to September 2021 that compared imaging techniques and provided sufficient data for diagnostic test accuracy meta-analysis. Methods: Abstract screening, full text review, and data extraction were done by a pair of independent reviewers. Nonnative and nonpyogenic patients were excluded. A bivariate random effect model was used for meta-analysis. Results: Twenty studies were included in the meta-analysis, encompassing a total of 1,123 imaging studies. The meta-analysis sensitivity and specificity of MRI were 90% and 72% respectively; those of PET/CT were 93% and 80%; those of ⁶⁷Ga were 95% and 88%; those of ^99mTc were 86% and 39%; and the sensitivity and specificity of combined Ga and Tc were 91% and 92% respectively in the setting of suspected NVO. Conclusions: ⁶⁷Ga has the highest sensitivity for NVO, and its specificity is augmented when combined with ^99mTc. MRI and PET/CT are both highly sensitive modalities, although the specificity of PET/CT is slightly better. MRI remains an appropriate initial test depending on the availability of other modalities.