Hye Mi Gweon MD, Presenter: Nothing to Disclose

Ji Hyun Youk MD, Abstract Co-Author: Nothing to Disclose

Jeong-Ah Kim MD, PhD, Abstract Co-Author: Nothing to Disclose

Eun Ju Son MD, PhD, Abstract Co-Author: Nothing to Disclose

To evaluate the interobserver agreement and the diagnostic performance of various qualitative values in shear-wave elastography (SWE) for breast masses.

B-mode US and SWE were performed for 152 women who had scheduled for US-guided core biopsy or surgical excision in 154 breast masses. SWE images were retrospectively recalled and the blinded two observers was asked to assess the follow qualitative features; E value: Ecol (6-point color score of maximum elasticity in the mass and surrounding tissue), Ehomo (homogeneity of elasticity within the lesion and surrounding tissue), Esha (lesion shape in SWE) proposed by Berg et al (Radiology 2012; 262:435)) and 4-color overlay pattern (1=blue homogeneous, 2=artifact, 3=localized colored area at the margin of the lesion, 4=heterogeneously colored area in the lesion) proposed by Tozaki et al (Acta radiol 2011;52:1069). The AUC obtained by using a ROC curve analysis was used to assess the diagnostic performance of qualitative values. Weighted kappa was used to assess the interobserver agreement of those values.

Thirty-nine masses (25.3%) were malignant. The better performing qualitative features were Ecol and color pattern (AUCs of 0.932 and 0.925) compared with Ehomo and Esha (AUCs of 0.857 and 0.864, p<0.05). Interobserver agreement was substantial for Ecol (κ=0.79), Ehomo (κ=0.77) and color pattern (κ=0.64), and moderate for Esha (κ=0.56). The AUC of B-mode US alone (0.950) was not significantly different from B-mode with E value and B-mode with color pattern (AUCs of 0.962 and 0.954). When all qualitative values were negative, leading to downgrade category 4a masses, the specificity significantly increased from 16.2% to 56.6% (E value) and 57.5% (color pattern) (p<0.001) without improvement in sensitivity. There was no significant difference between E value and color pattern in sensitivity, specificity and AUC.

The Ecol and color pattern had better diagnostic value than Ehomo and Esha. Adding qualitative SWE to BI-RADS increased specificity in decision making for biopsy recommendation. E value and color overlay pattern showed similar diagnostic performance

Qualitative value of SWE could be helpful for decision making for biopsy recommendation and increased diagnostic value of breast masses in ultrasound with good reproducibility

Gweon, H, Youk, J, Kim, J, Son, E, Qualitative Assessment in Shear-Wave Elastography for Breast Masses: Comparative Analysis of E Value and Color Overlay Pattern Classification.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12043510.html