title: Diagnostic Efficacy of UBI Scan in Musculoskeletal Infections.
abstract: BACKGROUND
  Limited recent studies have demonstrated that 99mTc-UBI scan can be a helpful method in precise diagnosis of infection. In the current study, we aimed to investigate the diagnostic efficacy of 99mTc-UBI scan in detection of musculoskeletal infections.
  
  
  METHODS
  Fifty patients with suspected musculoskeletal infections (painful THA, TKA, implant and nonunion) were enrolled in this study. After injection of 99mTc-Ubiquicidin 29-41, up to 30 minutes, dynamic imaging was performed every 1 minute. Whole body anterior and posterior images were acquired at 60 and 120 min (5 min/frame). A polygonal region of interest (ROI) was drawn manually around the area of increased accumulation of tracer (lesion) and anatomically similar area on the contralateral side (background) and the lesion to background ratio (LBR) was calculated. Then, patients underwent surgical procedures to assess infection by tissue sampling and histopathologic studies as gold standard. The receiver operating characteristics (ROC) analysis was performed to find a cut-off value for LBR and determining the diagnostic efficacy of UBI scan in musculoskeletal infections.
  
  
  RESULTS
  Histopathologic studies revealed infection in 38 patients. The mean LBR was significantly higher in infected patients (2.05 ± 0.41 vs. 1.52 ± 0.22; P < 0.001). ROC analysis showed that a cut-off point of 1.74 for LBR will have 94.7% sensitivity, 83.3% specificity and 92% accuracy for diagnosis of musculoskeletal infections.
  
  
  CONCLUSIONS
  UBI scan is a useful diagnostic tool for evaluation of patients with suspected musculoskeletal infection. However, UBI imaging has some limitations which result in some incorrect diagnoses. It is important to interpret the results of the scan with regard to the clinical findings.
authors.affiliation: Akhtar Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Ali Akbar
authors.initials: AA
authors.lastname: Esmailiejah
authors.affiliation: Akhtar Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran. mohammadreza.abbasian@gmail.com.
authors.forename: Mohammadreza
authors.initials: M
authors.lastname: Abbasian
authors.affiliation: Akhtar Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Salman
authors.initials: S
authors.lastname: Azarsina
authors.affiliation: Bone Joint and Related Tissue Research Center, Akhtar Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Farshad
authors.initials: F
authors.lastname: Safdari
authors.affiliation: Shohada Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Mahasti
authors.initials: M
authors.lastname: Amoui
authors.affiliation: Shohada Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Samaneh
authors.initials: S
authors.lastname: Hosseinzadeh
mesh_terms: D000328:Adult; D003952:Diagnostic Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007239:Infections / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009140:Musculoskeletal Diseases / Q000000981:diagnostic imaging* / Q000473:pathology; D015609:Organotechnetium Compounds / Q000737:chemistry; D010446:Peptide Fragments / Q000737:chemistry; D012372:ROC Curve; D011877:Radionuclide Imaging; D012680:Sensitivity and Specificity
chemical_list: D015609:Organotechnetium Compounds; D010446:Peptide Fragments; C485080:technetium 99m ubiquicidin(29-41)