title: Meta-analysis of quantitative diffusion-weighted MR imaging in the differential diagnosis of breast lesions.
abstract: BACKGROUND
  To determine, in a meta-analysis, the diagnostic performance of quantitative diffusion-weighted (DW) MR imaging in patients with breast lesions.
  
  
  METHODS
  English and Chinese studies published prior to June 2009 to assess the diagnostic performance of quantitative DWI in patients with breast lesions were reviewed and summarized with reference to the inclusion and exclusion criteria. Methodological quality was assessed by using the quality assessment of diagnostic studies (QUADAS) instrument. Publication bias analysis was performed by using Comprehensive Meta-analysis version 2. Meta-Disc version 1.4 was used to describe primary results and explore homogeneity by Chi-square test and inconsistency index; to explore threshold effect by receiver operator characteristic (ROC) space and Spearman correlation coefficient; and to pool weighted sensitivity and specificity by fixed or random effect model. A summary ROC (sROC) curve was constructed to calculate the area under the curve (AUC).
  
  
  RESULTS
  Of 65 eligible studies, 13 with 615 malignant and 349 benign lesions were included in the original meta-analysis, among which heterogeneity arising from factors other than threshold effect and publication bias was explored. Methodological quality was moderate. The pooled weighted sensitivity and specificity with corresponding 95% confidence interval (CI) in one homogenous subgroup of studies using maximum b = 1000 s/mm2 were 0.84 (0.80, 0.87) and 0.84 (0.79, 0.88) respectively. AUC of sROC was 0.9085. Sensitivity analysis demonstrated that the pooled estimates were stable and reliable.
  
  
  CONCLUSIONS
  Quantitative DWI has a higher specificity to differentiate between benign and malignant breast lesions compared to that of contrast-enhanced MRI. However, large scale randomized control trials (RCTs) are necessary to assess its clinical value because of disunified diffusion gradient factor b and diagnosis threshold.
authors.affiliation: Department of Radiology, First Affiliated Hospital of Medical College of Xi'an Jiaotong University, Xi'an, Shannxi, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Chen
authors.forename: Wen-ling
authors.initials: WL
authors.lastname: Li
authors.forename: Yi-li
authors.initials: YL
authors.lastname: Zhang
authors.forename: Qian
authors.initials: Q
authors.lastname: Wu
authors.forename: You-min
authors.initials: YM
authors.lastname: Guo
authors.forename: Zhi-lan
authors.initials: ZL
authors.lastname: Bai
mesh_terms: D001941:Breast Diseases / Q000175:diagnosis*; D001943:Breast Neoplasms / Q000175:diagnosis*; D016009:Chi-Square Distribution; D003287:Contrast Media; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D011237:Predictive Value of Tests; D012372:ROC Curve; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media