title: Diagnosing cysts with correlation coefficient images from 2-dimensional freehand elastography.
abstract: OBJECTIVE
  We compared the diagnostic potential of using correlation coefficient images versus elastograms from 2-dimensional (2D) freehand elastography to characterize breast cysts.
  
  
  METHODS
  In this preliminary study, which was approved by the Institutional Review Board and compliant with the Health Insurance Portability and Accountability Act, we imaged 4 consecutive human subjects (4 cysts, 1 biopsy-verified benign breast parenchyma) with freehand 2D elastography. Data were processed offline with conventional 2D phase-sensitive speckle-tracking algorithms. The correlation coefficient in the cyst and surrounding tissue was calculated, and appearances of the cysts in the correlation coefficient images and elastograms were compared.
  
  
  RESULTS
  The correlation coefficient in the cysts was considerably lower (14%-37%) than in the surrounding tissue because of the lack of sufficient speckle in the cysts, as well as the prominence of random noise, reverberations, and clutter, which decorrelated quickly. Thus, the cysts were visible in all correlation coefficient images. In contrast, the elastograms associated with these cysts each had different elastographic patterns. The solid mass in this study did not have the same high decorrelation rate as the cysts, having a correlation coefficient only 2.1% lower than that of surrounding tissue.
  
  
  CONCLUSIONS
  Correlation coefficient images may produce a more direct, reliable, and consistent method for characterizing cysts than elastograms.
authors: Department of Radiology, University of Michigan, 1500 E Medical Center Dr, Ann Arbor, MI 48109-0553 USA.
authors: Rebecca C
authors: RC
authors: Booi
authors: Paul L
authors: PL
authors: Carson
authors: Matthew
authors: M
authors: O'Donnell
authors: Michael S
authors: MS
authors: Richards
authors: Jonathan M
authors: JM
authors: Rubin
mesh_terms: D000465:Algorithms; D047688:Breast Cyst / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D004548:Elasticity; D005260:Female; D006801:Humans; D016217:Ultrasonography, Mammary / Q000379:methods*