title: Diagnostic value of whole-body diffusion-weighted magnetic resonance imaging for detection of primary and metastatic malignancies: a meta-analysis.
abstract: OBJECTIVE
  To perform a meta-analysis to evaluate the diagnostic performance of whole-body diffusion-weighted magnetic resonance imaging (WB-DWI) technique in detection of primary and metastatic malignancies compared with that of whole-body positron emission tomography/computed tomography (WB-PET/CT).
  
  
  METHODS
  Search Pubmed, MEDLINE, EMBASE and Cochrane Library database from January 1984 to July 2013 for studies comparing WB-DWI with WB-PET/CT for detection of primary and metastatic malignancies. Methodological quality was assessed by the quality assessment of diagnostic studies (QUADAS) instrument. Sensitivities, specificities, predictive values, diagnostic odds ratio (DOR) and areas under the summary receiver operator characteristic curve (AUC) were calculated. Potential threshold effect, heterogeneity and publication bias were investigated.
  
  
  RESULTS
  Thirteen eligible studies were included, with a total of 1067 patients. There was no significant threshold effect. WB-DWI had a similar AUC (0.966 (95% CI, 0.940-0.992) versus 0.984 (95% CI, 0.965-0.999)) with WB-PET/CT. No significant difference was detected between AUC of WB-DWI and WB-PET/CT. WB-DWI had a pooled sensitivity of 0.897 (95% CI, 0.876-0.916) and a pooled specificity of 0.954 (95% CI, 0.944-0.962). WB-PET/CT had a pooled sensitivity of 0.895 (95% CI, 0.865-0.920) and a pooled specificity of 0.975 (95% CI, 0.966-0.981). Heterogeneity was found to stem primarily from data type (per lesion versus per patient), MR sequence (DWIBS only and DWIBS with other sequence), and primary lesion type (single type and multiple type). The Deeks's funnel plots suggested the absence of publication bias.
  
  
  CONCLUSIONS
  WB-DWI has similar, good diagnostic performance for the detection of primary and metastatic malignancies compared with WB-PET/CT. DWIBS with other MR sequences could further improve the diagnostic performance. More high-quality studies regarding comparison of WB-DWI and WB-PET/CT and combination of them in detecting malignancies are still needed to be conducted.
authors.affiliation: Department of Radiology, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai 200003, China. Electronic address: lllb146@163.com.
authors.forename: Bin
authors.initials: B
authors.lastname: Li
authors.affiliation: Department of Radiology, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai 200003, China.
authors.forename: Qiong
authors.initials: Q
authors.lastname: Li
authors.affiliation: Department of Respiratory Disease, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai 200003, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Nie
authors.affiliation: Department of Radiology, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai 200003, China. Electronic address: lsy20112077@163.com.
authors.forename: Shiyuan
authors.initials: S
authors.lastname: Liu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000706:statistics & numerical data; D009362:Neoplasm Metastasis / Q000175:diagnosis*; D009369:Neoplasms / Q000175:diagnosis* / Q000453:epidemiology*; D049268:Positron-Emission Tomography / Q000706:statistics & numerical data*; D015995:Prevalence; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data*; D051598:Whole Body Imaging / Q000706:statistics & numerical data*; D055815:Young Adult
keywords: Computed tomography; Diagnostic value; Malignancies; Meta-analysis; Positron emission tomography; Whole-body DWI