Differentiating benign from malignant solid breast masses: value of shear wave elastography according to lesion stiffness combined with greyscale ultrasound according to BI-RADS classification.
BACKGROUND
The aim of this study was to assess the performance of shear wave elastography combined with BI-RADS classification of greyscale ultrasound images for benign/malignant differentiation in a large group of patients.


METHODS
One hundred and seventy-five consecutive patients with solid breast masses on routine ultrasonography undergoing percutaneous biopsy had the greyscale findings classified according to the American College of Radiology BI-RADS. The mean elasticity values from four shear wave images were obtained.


RESULTS
For mean elasticity vs greyscale BI-RADS, the performance results against histology were sensitivity: 95% vs 95%, specificity: 77% vs 69%, Positive Predictive Value (PPV): 88% vs 84%, Negative Predictive Value (NPV): 90% vs 91%, and accuracy: 89% vs 86% (all P>0.05). The results for the combination (positive result from either modality counted as malignant) were sensitivity 100%, specificity 61%, PPV 82%, NPV 100%, and accuracy 86%. The combination of BI-RADS greyscale and shear wave elastography yielded superior sensitivity to BI-RADS alone (P=0.03) or shear wave alone (P=0.03). The NPV was superior in combination compared with either alone (BI-RADS P=0.01 and shear wave P=0.02).


CONCLUSIONS
Together, BI-RADS assessment of greyscale ultrasound images and shear wave ultrasound elastography are extremely sensitive for detection of malignancy.
Dundee Cancer Centre, Ninewells Hospital and Medical School, University of Dundee, Mailbox 4, Dundee DD1 9SY, UK. a.z.evans@dundee.ac.uk
A
A
Evans
P
P
Whelehan
K
K
Thomson
K
K
Brauer
L
L
Jordan
C
C
Purdie
D
D
McLean
L
L
Baker
S
S
Vinnicombe
A
A
Thompson
D000328:Adult; D001706:Biopsy / Q000379:methods; D001941:Breast Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D003937:Diagnosis, Differential; D054459:Elasticity Imaging Techniques / Q000379:methods; D005260:Female; D006801:Humans; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016217:Ultrasonography, Mammary / Q000379:methods