title: Standard-b-Value Versus Low-b-Value Diffusion-Weighted Imaging in Hepatic Lesion Discrimination: A Meta-analysis.
abstract: OBJECTIVE
  We sought to determine the comparative diagnostic performance of standard-b-value (500-1000s/mm) versus low-b-value (≤500 s/mm) diffusion-weighted imaging (DWI) in the discrimination of hepatic lesions.
  
  
  METHODS
  A total of 1775 hepatic malignant lesions and 1120 benign hepatic lesions from 21 studies were included.
  
  
  RESULTS
  (1) The global sensitivity was 0.86 (95% confidence interval [CI], 0.847-0.879), the specificity was 0.82 (95% CI, 0.797-0.842), the positive likelihood ratio (PLR) was 6.234 (95% CI, 4.260-9.123), the negative likelihood ratio (NLR) was 0.175 (95% CI, 0.135-0.227), and diagnostic odds ratio (DOR) was 42.836 (95% CI, 24.134-76.031). The area under the curve (AUC) and Q* index were 0.93 and 0.87. Publication bias was not present (P > 0.05). (2)The sensitivity of a subgroup meta-analysis of standard-b-value DWI was 0.858 (95% CI, 0.835-0.880), the specificity was 0.836 (95% CI, 0.807-0.863), the PLR was 6.527 (95% CI, 3.857-11.046), the NLR was 0.168 (95% CI, 0.123-0.239), and the DOR was 49.716 (95% CI, 22.897-107.98). The AUC and Q* index were 0.941 and 0.88. (3)The sensitivity of a subgroup meta-analysis of low-b-value DWI was 0.87 (95% CI, 0.84-0.89), the specificity was 0.80 (95% CI, 0.76-0.83), the PLR was 6.22 (95% CI, 3.29-11.76), the NLR was 0.19 (95% CI, 0.12-0.29), and the DOR was 37.14 (95% CI, 14.80-93.18). The AUC and Q* index were 0.922 and 0.86.
  
  
  CONCLUSIONS
  Hepatic DWI is useful in differentiating between malignant and benign hepatic lesions. Standard-b-value DWI displayed an overall superior diagnostic accuracy over low-b-value DWI. Further trials needed to determine whether increasing b values beyond 1000 s/mm affects the diagnostic accuracy of hepatic lesion discrimination.
authors.affiliation: From the *Medical College of Nanchang University; †Jiangxi Health Vocational College; and ‡Department of Burn, The First Affiliated Hospital of Nanchang University, Nanchang, People's Republic of China.
authors.forename: Hui
authors.initials: H
authors.lastname: Xiong
authors.forename: Yuan-Lin
authors.initials: YL
authors.lastname: Zeng
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods / Q000592:standards*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D017410:Practice Guidelines as Topic; D015995:Prevalence; D015203:Reproducibility of Results; D018570:Risk Assessment; D012307:Risk Factors; D012680:Sensitivity and Specificity