title: Whole-lesion histogram analysis metrics of the apparent diffusion coefficient as a marker of breast lesions characterization at 1.5 T.
abstract: BACKGROUND
  To retrospectively assess the role of whole-lesion apparent diffusion coefficient (ADC) in the characterization of breast tumors by comparing different histogram metrics.
  
  
  METHODS
  49 patients with 53 breast lesions underwent magnetic resonance imaging (MRI). ADC histogram parameters, including the mean, mode, 10th/50th/90th percentile, skewness, kurtosis, and entropy ADCs, were derived for the whole-lesion volume in each patient. Mann-Whitney U-test, area under the receiver-operating characteristic curve (AUC) were used for statistical analysis.
  
  
  RESULTS
  The mean, mode and 10th/50th/90th percentile ADC values were significantly lower in malignant lesions compared with benign ones (all P < 0.0001), while skewness was significantly higher in malignant lesions P = 0.02. However, no significant difference was found between entropy and kurtosis values in malignant lesions compared with benign ones (P = 0.06 and P = 1.00, respectively). Univariate logistic regression showed that 10th and 50th percentile ADC yielded the highest AUC (0.985; 95% confidence interval [CI]: 0.902, 1.000 and 0.982; 95% confidence interval [CI]: 0.896, 1.000 respectively), whereas kurtosis value yielded the lowest AUC (0.500; 95% CI: 0.355, 0.645), indicating that 10th and 50th percentile ADC values may be more accurate for lesion discrimination.
  
  
  CONCLUSIONS
  Whole-lesion ADC histogram analysis could be a helpful index in the characterization and differentiation between benign and malignant breast lesions with the 10th and 50th percentile ADC be the most accurate discriminators.
authors.affiliation: University Hospital of Ioannina, Greece. Electronic address: bbougias@yahoo.gr.
authors.forename: H
authors.initials: H
authors.lastname: Bougias
authors.affiliation: Iaso Maternity Hospital, Athens, Greece.
authors.forename: A
authors.initials: A
authors.lastname: Ghiatas
authors.affiliation: Iaso Maternity Hospital, Athens, Greece.
authors.forename: D
authors.initials: D
authors.lastname: Priovolos
authors.affiliation: General Hospital of Ioannina "G.Hatzikosta", Greece.
authors.forename: K
authors.initials: K
authors.lastname: Veliou
authors.affiliation: Doncaster and Bassetlaw Hospitals NHS Foundation Trust, Doncaster, UK.
authors.forename: A
authors.initials: A
authors.lastname: Christou
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D003627:Data Interpretation, Statistical; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008875:Middle Aged; D012189:Retrospective Studies
keywords: DWI; Heterogeneity; Histogram analysis