title: Benefits of hybrid SPECT/CT for (111)In-oxine- and Tc-99m-hexamethylpropylene amine oxime-labeled leukocyte imaging.
abstract: BACKGROUND
  This retrospective study assessed the effect of the addition of SPECT/CT imaging on the diagnostic accuracy of labeled leukocyte scintigraphy.
  
  
  METHODS
  Leukocyte scans of 134 patients performed between December 2005 and December 2009 were reviewed. All patients underwent whole-body planar and SPECT/CT imaging with either (111)In-oxine- or Tc-99m-hexamethylpropylene amine oxime (HMPAO)-labeled leukocytes. Leukocyte imaging identified a total of 221 lesions. Based on additional diagnostic tests and clinical follow-up, a final diagnosis was established in 115 patients.
  
  
  RESULTS
  A total of 113 focal lesions with an established final diagnosis were detected on imaging in bone (n = 43), soft-tissues (n = 34), vascular grafts (n = 19), and other surgical implants (n = 17), whereas 26 scans resulted negative. Overall, leukocyte scanning including SPECT/CT yielded sensitivity, specificity, positive and negative predictive values of 87.5%, 85.3%, 83.6%, and 88.9%, respectively. As compared to planar imaging and SPECT, SPECT/CT imaging significantly increased the number of correctly identified lesion locations and improved overall reader confidence in 77 (68%) and 71 (63%) of 113 focal lesions, respectively (P < 0.001). Significant differences in scan accuracy were neither observed between In-oxine- or Tc-99m-hexamethylpropylene amine oxime-labeled leukocyte studies, nor between scans obtained with or without antibiotic treatment.
  
  
  CONCLUSIONS
  Hybrid SPECT/CT leukocyte imaging has incremental value over planar imaging with SPECT because of improved diagnostic accuracy of lesion identification and reader confidence.
authors.affiliation: Division of Nuclear Medicine, Radiology Department, The University of Michigan, Ann Arbor, MI, USA. mehdi.djekidel@yale.edu
authors.forename: Mehdi
authors.initials: M
authors.lastname: Djekidel
authors.forename: Richard K J
authors.initials: RK
authors.lastname: Brown
authors.forename: Morand
authors.initials: M
authors.lastname: Piert
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000890:Anti-Infective Agents / Q000494:pharmacology / Q000627:therapeutic use; D005260:Female; D006801:Humans; D007962:Leukocytes / Q000000981:diagnostic imaging* / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D009942:Organometallic Compounds; D015125:Oxyquinoline / Q000031:analogs & derivatives*; D013194:Staining and Labeling; D019690:Technetium Tc 99m Exametazime; D015899:Tomography, Emission-Computed, Single-Photon; D014057:Tomography, X-Ray Computed
chemical_list: D000890:Anti-Infective Agents; D009942:Organometallic Compounds; C032950:indium oxine; D019690:Technetium Tc 99m Exametazime; D015125:Oxyquinoline