title: Heterogeneity analysis of Gd-DTPA uptake: improvement in breast lesion differentiation.
abstract: OBJECTIVE
  The aim of this study was to assess whether lesion heterogeneity through pixel-by-pixel analysis of contrast-enhanced MR parameter maps would improve breast lesion differentiation.
  
  
  METHODS
  Forty-nine female patients with primary tumors of the breast were imaged using contrast-enhanced MRI. The rate of transfer of contrast medium between the lesion and plasma was calculated via compartmental modeling over semiautomatically delineated regions of interest. The distributions of transfer rate values were subdivided into 10 segments for each lesion. The rate of change of the statistical moments of the transfer rate measured over the 10 segments allowed a quantitative measure of heterogeneity.
  
  
  RESULTS
  In this patient group of 25 malignant and 25 benign lesions, improved differentiation was achieved by using a measure of lesion heterogeneity. The sensitivity and specificity obtained were 88 and 88%, respectively, compared with 84 and 76% when using the mean value of the transfer rate coefficient.
  
  
  CONCLUSIONS
  Pixel-by-pixel analysis of contrast medium transfer rate maps allows the examination of lesion heterogeneity and offers improved lesion differentiation. The new method used to quantify lesion heterogeneity relies on the manner in which the exchange rate parameter varies when calculated over different segments of the distribution.
authors.affiliation: Centre for Magnetic Resonance Investigations, Hull Royal Infirmary, England, UK.
authors.forename: B
authors.initials: B
authors.lastname: Issa
authors.forename: D L
authors.initials: DL
authors.lastname: Buckley
authors.forename: L W
authors.initials: LW
authors.lastname: Turnbull
mesh_terms: D000328:Adult; D001940:Breast / Q000473:pathology*; D001941:Breast Diseases / Q000175:diagnosis; D001943:Breast Neoplasms / Q000175:diagnosis*; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA