Sonoelastographic strain index for differentiation of benign and malignant nonpalpable breast masses.
OBJECTIVE
The purpose of this study was to evaluate the diagnostic potential of the sonoelastographic strain index for differentiation of nonpalpable breast masses.


METHODS
Ninety-nine nonpalpable breast masses (79 benign and 20 malignant) in 94 women (mean age, 45 years; range, 21-68 years) who had been scheduled for a sonographically guided core biopsy were examined with B-mode sonography and sonoelastography. Radiologists who had performed the biopsies analyzed the B-mode sonograms and provided American College of Radiology Breast Imaging Reporting and Data System categories. The strain index (fat to lesion strain ratio) was calculated by dividing the strain value of the subcutaneous fat by that of the mass. The histologic result from the sonographically guided core biopsy was used as a reference standard. The diagnostic performance of the strain index and that of B-mode sonography were compared by receiver operating characteristic (ROC) curve analysis.


RESULTS
The mean strain index values +/- SD were 6.57 +/- 6.62 (range, 1.29-28.69) in malignant masses and 2.63 +/- 4.57 (range, 0.54-38.76) in benign masses (P = .019). The area under the ROC curve values were 0.835 (95% confidence interval [CI], 0.747-0.902) for B-mode sonography and 0.879 (95% CI, 0.798-0.936) for the strain index (P = .490). The sensitivity, specificity, positive predictive value, and negative predictive value were 95% (19 of 20), 75% (59 of 79), 48% (19 of 39), and 98% (59 of 60), respectively, when a best cutoff point of 2.24 was used.


CONCLUSIONS
The strain index based on the fat to lesion strain ratio has diagnostic performance comparable with that of B-mode sonography for differentiation of benign and malignant breast masses.
Cho
Nariya
N
Department of Radiology and Clinical Research Institute,Seoul National University Hospital, 101 Daehangno, Jongno-gu, Seoul 110-744, Korea.
Moon
Woo Kyung
WK
Kim
Ha Young
HY
Chang
Jung Min
JM
Park
Sang Hee
SH
Lyou
Chae Yeon
CY
D000273:Adipose Tissue / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D000328:Adult; D000368:Aged; D000465:Algorithms; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D003937:Diagnosis, Differential; D055119:Elastic Modulus; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016217:Ultrasonography, Mammary / Q000379:methods*