The negative predictive value of electrical impedance scanning in BI-RADS category IV breast lesions.
OBJECTIVE
We sought to prospectively assess the value of electrical impedance scanning (EIS) in discriminating benign from malignant lesions classified as BI-RADS category IV in mammography in comparison with ultrasound (US), with a special focus on negative prediction.


METHODS
EIS was performed on 128 BI-RADS category IV lesions in 121 women (mean, 51.8 years). The newly developed EIS software 2.67 calculates a BI-RADS-like level of suspicion (LOS) on a 5-grade scale. LOS 1, 2, and 3 were considered negative; LOS 4 and 5 were considered positive. Histopathologic results were obtained in all lesions.


RESULTS
Histology proved 37 lesions malignant, 91 benign. Sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of EIS compared with US were 94.6%, 74.7%, 80.5%, 60.3%, 97.1% versus 90.5%, 33.8%, 47.2%, 29.7%, 92.0%, respectively. In 43 lesions sized < or = 10 mm, EIS demonstrated better sensitivity, specificity, accuracy, PPV, and NPV of 100%, 83.3%, 90.7%, 82.6%, and 100%, respectively. Although NPV was also high, US showed no sufficient results in 39 (30.5%) lesions because of microcalcifications. Receiver operating curve analysis revealed best results for a combined use of US and EIS.


CONCLUSIONS
With a NPV of 97.1% of EIS in BI-RADS category IV breast lesions, a negative result in these lesions could be firm indication to manage them as BI-RADS-category III and refer patients for a 6-month short-interval follow-up rather than performing a biopsy. The best adjunctive diagnostic performance can be achieved by a combination of US and EIS. Costs and patient morbidity could be minimized.
Fuchsjaeger
Michael H
MH
Department of Radiology, Medical University of Vienna, Vienna, Austria. Michael.Fuchsjaeger@meduniwien.ac.at
Flöry
Daniel
D
Reiner
Cäcilia S
CS
Rudas
Margarete
M
Riedl
Christopher C
CC
Helbich
Thomas H
TH
D001940:Breast / Q000473:pathology*; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging; D003937:Diagnosis, Differential; D017097:Electric Impedance; D005260:Female; D006801:Humans; D008875:Middle Aged; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D016217:Ultrasonography, Mammary