title: Diagnostic performance of USPIO-enhanced MRI for lymph-node metastases in different body regions: a meta-analysis.
abstract: OBJECTIVE
  USPIO (ultrasmall superparamagnetic iron oxide contrast agent) MRI was a promising imaging modality in the detection of lymph-node metastases. And this meta-analysis is performed to compare the diagnostic accuracy of USPIO-enhanced MRI with non-enhanced MRI, USPIO-enhanced MRI in various body regions, and postcontrast alone for diagnosis of lymph-node metastases.
  
  
  METHODS
  A comprehensive and systematic search was conducted in PubMed and EMBASE databases. After a systematic review of the studies, sensitivity, specificity, the Q* value and other measures of accuracy of USPIO-enhanced MRI in the diagnosis of lymph-node metastases were summarized. The overall test performance was based on summary receiver operating characteristic curves.
  
  
  RESULTS
  Summary of ROC curve analysis for per-lymph-node data shows a pooled sensitivity of 0.90 (95% confidential interval [CI]: 0.88-0.91) and overall specificity of 0.96 (95% CI: 0.95-0.97) for USPIO-enhanced MRI, the Q* value for USPIO-enhanced MRI is 0.9195, diagnostic odds ratio (DOR) is 162.28 (95% CI: 91.82-286.81). Non-enhanced MRI had less overall sensitivity 0.39 (95% CI: 0.34-0.43) and specificity 0.90 (95% CI: 0.89-0.91), respectively, the Q* value for USPIO-enhanced MRI was 0.6321, DOR is 5.81 (95% CI: 3.64-9.82). Postcontrast MRI alone had sensitivity 0.85 (95% CI: 0.81-0.88) and specificity 0.93 (95% CI: 0.91-0.95), respectively, the Q* value for USPIO-enhanced MRI was 0.8976, DOR is 76.92 (95% CI: 34.21-172.93). There was significant heterogeneity for studies reporting enhanced MRI and non-enhanced MRI.
  
  
  CONCLUSIONS
  This meta-analysis has shown that USPIO-enhanced MRI offers higher diagnostic performance than conventional MRI, and is sensitive and specific for the detection of lymph-node metastases. Postcontrast images alone can equate diagnostic performance pre- and postcontrast MRI has achieved for lymph-node characterization. And the role of USPIO-enhanced MRI in clinical practice still needs to be investigated in future studies.
authors.affiliation: Department of Colorectal and Anal Surgery, First Affiliated Hospital, Guangxi Medical University, Nanning, Guangxi, PR China.
authors.forename: Liucheng
authors.initials: L
authors.lastname: Wu
authors.forename: Yunfei
authors.initials: Y
authors.lastname: Cao
authors.forename: Cun
authors.initials: C
authors.lastname: Liao
authors.forename: Jiahao
authors.initials: J
authors.lastname: Huang
authors.forename: Feng
authors.initials: F
authors.lastname: Gao
mesh_terms: D003287:Contrast Media; D003911:Dextrans; D006801:Humans; D008207:Lymphatic Metastasis / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D058185:Magnetite Nanoparticles; D012372:ROC Curve; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D003911:Dextrans; D058185:Magnetite Nanoparticles; C097921:ferumoxtran-10