title: Preoperative evaluation of the histological grade of hepatocellular carcinoma with diffusion-weighted imaging: a meta-analysis.
abstract: OBJECTIVE
  To evaluate the diagnostic performance of diffusion-weighted imaging (DWI) in the preoperative prediction of the histological grade of hepatocellular carcinoma (HCC).
  
  
  METHODS
  A comprehensive literature search was performed in several authoritative databases to identify relevant articles. QUADAS-2 was used to assess the quality of included studies. Data were extracted to calculate the pooled sensitivity, specificity, positive likelihood ratio (PLR) and negative likelihood ratio (NLR). Summary receiver operating characteristic (SROC) curves were derived and areas under the SROC curve (AUC) were computed to indicate the diagnostic accuracy. Heterogeneity test, meta-regression analysis and sensitivity analysis were performed to identify factors and studies contributed to the heterogeneity.
  
  
  RESULTS
  A total of 11 studies with 912 HCCs were included in this meta-analysis. The pooled sensitivity, specificity, PLR and NLR with corresponding 95% confidence intervals (CI) were 0.54(0.47-0.61), 0.90(0.87-0.93), 4.88(2.99-7.97) and 0.46(0.27-0.77) for the prediction of well-differentiated HCC (w-HCC), 0.84(0.78-0.89), 0.48(0.43-0.52), 2.29(1.43-3.69) and 0.30(0.22-0.41) for the prediction of poorly-differentiated HCC (p-HCC). The AUC were 0.9311 and 0.8513 in predicting w-HCC and p-HCC, respectively. Results were further evaluated according to the method of image interpretation. Significant heterogeneity was observed.
  
  
  CONCLUSIONS
  DWI had excellent and moderately high diagnostic accuracy for the detection of w-HCC and p-HCC, respectively. Nonetheless, further studies in larger populations and an optimized image acquisition and interpretation are required before DWI-derived parameters can be used as a useful image biomarker for the prediction of the histological grade of HCC.
authors: Department of Radiology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, P. R. China.
authors: Jie
authors: J
authors: Chen
authors: Department of Radiology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, P. R. China.
authors: Mingpeng
authors: M
authors: Wu
authors: Department of Radiology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, P. R. China.
authors: Rongbo
authors: R
authors: Liu
authors: Department of Radiology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, P. R. China.
authors: Siyi
authors: S
authors: Li
authors: Department of Radiology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, P. R. China.
authors: Ronghui
authors: R
authors: Gao
authors: Department of Radiology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, P. R. China.
authors: Bin
authors: B
authors: Song
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D006801:Humans; D008113:Liver Neoplasms / Q000473:pathology*; D060787:Neoplasm Grading; D011300:Preoperative Care; D012680:Sensitivity and Specificity