A prospective study comparing whole-body FDG PET/CT to combined planar bone scan with 67Ga SPECT/CT in the Diagnosis of Spondylodiskitis

Clin Nucl Med. 2012 Sep;37(9):827-32. doi: 10.1097/RLU.0b013e318262ae6c.


Purpose: This study aimed to prospectively evaluate the usefulness of PET/CT using F-FDG in comparison to bone scan and Ga in the diagnosis of spondylodiskitis.

Material and methods: This prospective study included 34 patients (15 women and 19 men) aged 59 (18) years with clinical symptoms of spondylodiskitis. Whole-body PET/CT and bone scan combined with planar and SPECT/CT Ga was performed in all patients. Diagnosis of spondylodiskitis was made by microbiology and/or on the basis of clinical and laboratory findings and imaging follow-up.

Results: Spondylodiskitis was confirmed in 18 of 34 patients. In the other 16 patients, spondylodiskitis was finally excluded, and the most frequent findings observed were degenerative spondyloarthropathy (n = 7), vertebral fracture (n = 3), endocarditis (n = 2), and other processes (n = 4). The sensitivity and specificity of combined bone scan and Ga were 78% and 81%, with a positive predictive value of 82%, a negative predictive value of 76%, and an overall accuracy of 79%. SPECT/CT with Ga helped identify soft tissue involvement in 10 of 18 patients. The sensitivity and specificity of PET/CT were 89% and 88%, with a positive predictive value of 89%, a negative predictive value of 87%, and an overall accuracy of 88%. Concordance between Ga and PET/CT was good (κ = 0.71; 95% confidence interval, 0.48-0.94). PET/CT was able to detect soft tissue involvement in 12 of 18 patients. In 2 patients, a multifocality was found, which was only diagnosed by PET/CT.

Conclusions: PET/CT is useful in the diagnosis of spondylodiskitis, with more accurate results than combined bone scan and Ga. SPECT/CT with Ga is recommended, especially when planar bone scan and Ga pattern is suggestive of spondylodiskitis.

Publication types

  • Clinical Trial
  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Bone and Bones / diagnostic imaging*
  • Discitis / diagnostic imaging*
  • Discitis / microbiology
  • Female
  • Fluorodeoxyglucose F18*
  • Gallium Radioisotopes
  • Humans
  • Male
  • Middle Aged
  • Multimodal Imaging / methods*
  • Positron-Emission Tomography*
  • Prospective Studies
  • Tomography, X-Ray Computed*
  • Whole Body Imaging / methods*
  • Young Adult


  • Gallium Radioisotopes
  • Fluorodeoxyglucose F18