Added value of [ 18 F]fluorodeoxyglucose positron emission tomography/computed tomography for the diagnosis of post-operative instrumented spine infection

Joint Bone Spine. 2019 Jul;86(4):503-508. doi: 10.1016/j.jbspin.2019.01.009. Epub 2019 Jan 31.

Abstract

Purpose: Post-operative instrumented spine infection (PISI) is an infrequent complication. Diagnosis of spinal implant infection can be difficult, especially in case of chronic infection.

Methods: This retrospective study attempts to evaluate the diagnostic performance of [18F]fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) in PISI. Imagings were performed between April 2010 and June 2018 among patients referred for suspected chronic spinal implant infection. PET/CT were performed more than 12 weeks after surgery. PET/CT images were re-interpreted independently by two nuclear medicine physicians without knowledge of the patient's conditions. PET/CT data were analyzed both visually and semi-quantitatively (SUVmax). MRI results were collected from medical records. The final diagnosis of infection was based on bacteriological cultures or a twelve-month follow-up.

Results: Forty-nine PET/CT were performed in 44 patients (22 women, median age 65.0 years). Twenty-two patients had a diagnosis of infection during follow-up. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for PET/CT were 86.4%, 81.5%, 79.2%, and 88.0%. Sensitivity, specificity, PPV and NPV were 66.7%, 75.0%, 66.0%, 75.0% respectively for MRI and 50.0%, 92.6%, 84.6% and 69.4% for serum C-reactive protein (CRP). Although these values were higher for PET/CT than for MRI or CRP, the differences were not statistically significant. In this setting, false positives with PET/CT can be observed in case of previous spine infection or adjacent segments disc disease. False negatives can result of extensive instrumented arthrodesis or infection with low virulence bacteria.

Conclusion: PET/CT is useful for the diagnosis of PISI. These results should be evaluated in further prospective study.

Keywords: Implant; Spine infection; [(18)F]fluorodeoxyglucose positron emission tomography/computed tomography.

Publication types

  • Observational Study

MeSH terms

  • Adult
  • Aged
  • Analysis of Variance
  • C-Reactive Protein / metabolism
  • Cohort Studies
  • Female
  • Fluorodeoxyglucose F18*
  • Humans
  • Internal Fixators / adverse effects
  • Magnetic Resonance Imaging / methods
  • Male
  • Middle Aged
  • Positron Emission Tomography Computed Tomography / methods*
  • Predictive Value of Tests
  • Prognosis
  • ROC Curve
  • Retrospective Studies
  • Spinal Diseases / diagnostic imaging
  • Spinal Diseases / surgery*
  • Spinal Fusion / adverse effects*
  • Spinal Fusion / methods
  • Surgical Wound Infection / diagnostic imaging*
  • Treatment Outcome

Substances

  • Fluorodeoxyglucose F18
  • C-Reactive Protein