Elastography for Breast Cancer Diagnosis: a Useful Tool for Small and BI-RADS 4 Lesions

Abstract

The present study aimed at evaluating and comparing the diagnostic performance of B-mode ultrasound (US), elastography score (ES), and strain ratio (SR) for the differentiation of breast lesions. This retrospective study enrolled 431 lesions from 417 in-hospital patients. All patients were examined with both conventional ultrasound and elastography. Two experienced radiologists reviewed ultrasound and elasticity images. The histopathologic result obtained from ultrasound-guided core biopsy or operation excisions were used as the reference standard. Pathologic examination revealed 276 malignant lesions (64%) and 155 benign lesions (36%). A cut-off point of 4.15 (area under the curve, 0.891) allowed significant differentiation of malignant and benign lesions. ROC (receiver-operating characteristic) curves showed a higher value for combination of B-mode ultrasound and elastography for the diagnosis of breast lesions. Conventional ultrasound combined elastography showed high sensitivity, specificity, and accuracy for group II lesions (10mm<lesion diameter ≤20mm). Elastography combined with conventional ultrasound show high specificity and accuracy for differentiation of benign and malignant breast lesions. Elastography is particularly important for the diagnosis of BI-RADS 4 and small breast lesions.

Implementation of Elastography Score and Strain Ratio in Combination with B-Mode Ultrasound Avoids Unnecessary Biopsies of Breast Lesions

“…By use of ROC analysis, optimal cutoff values for ES and SR were determined, and a modified BI-RADS category was calculated according to the following equation: Modified BI-RADS 5 BI-RADS 1 a 1 b, where a and b are the ES and SR scores, respectively (Lee et al 2014;Liu et al 2014;Yoon et al 2014). When the ES value was higher than the cutoff point, a was scored as 11; when the ES value was lower than the cutoff point, a was scored as 21; when it was equal Fig.…”

“…BI-RADS 4 lesions have a low to moderate probability of cancer (3%-94%) and biopsy/fine-needle aspiration cytology (FNAC) should be considered. However, with BI-RADS category 4, approximately 15% of findings are histologically malignant, and a much larger proportion of patients undergo invasive diagnostic procedures that might not be necessary if better imaging methods were available for accurate diagnosis confirmation (Liu et al 2014). Presently, biopsy is used as a supplement for other diagnostic methods in the evaluation of breast lesions, but the rate of cancer detection in biopsies ranges from only 10% to 30% (Chiou et al 2006;Duncan et al 2000).…”

“…Although some studies have reported that the SR is a highly valuable and more objective parameter for differentiating malignant and benign breast lesions than the ES (Shyam et al 2012;Thomas et al 2010;Yoon et al 2014), others have confirmed that the SR has poor reliability and does not improve elastographic accuracy (Kumm and Szabunio 2010;Yerli et al 2011). Additionally, only a few studies have investigated the usefulness and accuracy of SE with different-sized breast lesions (Giuseppetti et al 2005;Itoh et al 2006;Liu et al 2014).…”

Factors Affecting the Quality of Breast Quasistatic Ultrasound Elastograms

“…Elastographic techniques are mainly applied for differential diagnosis in various organs, including the breast, thyroid, liver, and prostate . The application of elastography for detecting breast lesions helps improve the accuracy of distinguishing between benign and malignant nodules and reduces the chance of an invasive biopsy for suspicious lesions …”

“…8 Elastographic techniques are mainly applied for differential diagnosis in various organs, including the breast, [9][10][11] thyroid, 12 liver, 13 and prostate. 14 The application of elastography for detecting breast lesions helps improve the accuracy of distinguishing between benign and malignant nodules 15,16 and reduces the chance of an invasive biopsy for suspicious lesions. 17,18 Varying stiffness of different tissues leads to different responses (such as different strain, a different vibration amplitude, and a different propagation speed of the sheer wave), which can be detected by elastography after applying an excitation in the elastic sampling frame.…”