The Clinical Significance of Real-Time Contrast-Enhanced Ultrasonography in the Differential Diagnosis of Breast Tumor

Modified Model for Diagnosing Breast Imaging Reporting and Data System Category 3 to 5 Breast Lesions: Retrospective Analysis and Nomogram Development

OBJECTIVES

The aim of this study was to explore a modified model to simplify the diagnostic process for American College of Radiology Breast Imaging Reporting and Data System category 3 to 5 breast lesions and evaluate the model's diagnostic efficacy.

METHODS

A retrospective review was conducted of breast lesions examined by B-mode ultrasound (US) and contrast-enhanced ultrasound (CEUS) and diagnosed by histopathologic examination from October 2016 to August 2019. The US characteristics of a combined model (US + CEUS model) with relatively high diagnostic value were selected by a lasso regression analysis to establish a modified model. Two nomograms were developed. The results were internally validated by bootstrap resampling.

RESULTS

Overall, 206 breast lesions in 198 patients, 136 benign and 70 malignant, were included. Ultrasound characteristics included in the modified model were shape, margin, microcalcification, enhanced intensity, enhanced scope, and enhanced time. For the US + CEUS model and modified model, sensitivities were 94.3% and 93.3%; specificities were 85.9% and 81.4%; accuracies were 89.3% and 88.7% and areas under the curve were 0.957 and 0.944, respectively. No statistically significant differences were seen in the diagnostic efficacies of the models (P = .097). Bootstrap-corrected sensitivities, specificities. and accuracies of the models were consistent with these results. Bootstrap-corrected areas under the curve for the US + CEUS model and the modified model were 0.955 and 0.940, respectively.

CONCLUSIONS

The modified model with fewer indicators conveniently and effectively diagnosed the malignancy of Breast Imaging Reporting and Data System category 3 to 5 breast lesions without reducing diagnostic efficacy.

Immunohistochemical index prediction of breast tumor based on multi-dimension features in contrast-enhanced ultrasound

Breast cancer is the leading killer of Chinese women. Immunohistochemistry index has great significance in the treatment strategy selection and prognosis analysis for breast cancer patients. Currently, histopathological examination of the tumor tissue through surgical biopsy is the gold standard to determine immunohistochemistry index. However, this examination is invasive and commonly causes discomfort in patients. There has been a lack of noninvasive method capable of predicting immunohistochemistry index for breast cancer patients. This paper proposes a machine learning method to predict the immunohistochemical index of breast cancer patients by using noninvasive contrast-enhanced ultrasound. A total of 119 breast cancer patients were included in this retrospective study. Each patient implemented the pathological examination of immunohistochemical expression and underwent contrast-enhanced ultrasound imaging of breast tumor. The multi-dimension features including 266 three-dimension features and 837 two-dimension dynamic features were extracted from the contrast-enhanced ultrasound sequences. Using the machine learning prediction method, 21 selected multi-dimension features were integrated to generate a model for predicting the immunohistochemistry index noninvasively. The immunohistochemical index of human epidermal growth factor receptor-2 (HER2) was predicted based on multi-dimension features in contrast-enhanced ultrasound sequence with the sensitivity of 71%, and the specificity of 79% in the testing cohort. Therefore, the noninvasive contrast-enhanced ultrasound can be used to predict the immunohistochemical index. To our best knowledge, no studies have been reported about predicting immunohistochemical index by using contrast-enhanced ultrasound sequences for breast cancer patients. Our proposed method is noninvasive and can predict immunohistochemical index by using contrast-enhanced ultrasound in several minutes, instead of relying totally on the invasive and biopsy-based histopathological examination. Graphical abstract Immunohistochemical index prediction of breast tumor based on multi-dimension features in contrast-enhanced ultrasound.

Comparison of transducers with different frequencies in breast contrast-enhanced ultrasound (CEUS) using SonoVue as contrast agent

OBJECTIVE

To explore the effectiveness of different transducers in breast contrast-enhanced ultrasound (CEUS) using SonoVue(®) (Bracco, Plan-Les-Ouates, Switzerland) as the contrast agent.

METHODS

Breast CEUS was performed in 51 patients with 51 breast lesions using a low-frequency transducer (probe C5-1) and a high-frequency transducer (probe L12-5) separately. All image processes were reviewed for the presence of local blood perfusion defects and surrounding vessels. McNemar's test was conducted to compare the detection effectiveness between these two transducers.

RESULTS

Pathological results revealed 38 malignant and 13 benign lesions. The two transducers showed no difference in detecting benign lesions. Among malignant lesions, CEUS conducted by probe C5-1 (frequency range from 1 to 5 MHz) presented 23 (60.5%) lesions with local blood perfusion defects and 26 (68.4%) lesions with surrounding vessels. Meanwhile, probe L12-5 (frequency range from 5 to 12 MHz) showed only 12 (31.6%) lesions with local blood perfusion defects and 12 (31.6%) lesions with surrounding vessel. Probe C5-1 was more sensitive than probe L12-5 in detecting malignant CEUS characteristics (p-value < 0.05).

CONCLUSION

The low-frequency transducer was more sensitive than the high-frequency transducer in breast CEUS using SonoVue as the contrast agent. A new contrast agent with a higher resonance frequency, specially designed for high-frequency transducers, may be helpful in improving the clinical value of breast CEUS.

ADVANCES IN KNOWLEDGE

The first study comparing different frequency transducers in breast CEUS of the same patient lesions. We brought out the requirement for CEUS contrast agents which are more suitable for high-frequency examinations.

Evaluation of Malignancy Grade of Breast Cancer Using Perflubutane-Enhanced Ultrasonography

Whether the contrast effects of perflubutane on contrast-enhanced ultrasonography can predict the malignancy grade of breast cancer is unknown. We analyzed associations between perfusion parameters created from time-intensity curves based on enhancement intensity and temporal changes in contrast-enhanced ultrasonography and clinicopathologic factors in 100 consecutive patients with invasive breast cancer. Values of perfusion parameters were significantly greater in estrogen receptor-negative than -positive tumors (peak intensity, p = 0.0002; ascending slope, p = 0.006; area under the curve, p = 0.0006). Variations in the peak intensity of Ki-67 were significantly correlated in all tumors (r = 0.54, p < 0.0001) and in luminal (r = 0.43, p = 0.0002), human epidermal growth factor receptor type 2-positive (r = 0.47, p = 0.047) and triple-negative (r = 0.55, p = 0.043) tumors. Perfusion parameters on contrast-enhanced ultrasonography can provide excellent predictive value for high-grade malignancy and might help to determine appropriate therapeutic strategies.

Differentiation of benign and malignant sub-1-cm breast lesions using contrast-enhanced sonography

OBJECTIVES

The purpose of this study was to prospectively assess the diagnostic efficacy of contrast-enhanced sonography for differential diagnosis of sub-1-cm breast lesions.

METHODS

Contrast-enhanced sonography was performed in 46 women with 46 sub-1-cm breast lesions scheduled for surgery or biopsy. Histologic results were used as a reference standard. The contrast enhancement pattern, enhancement degree, direction, margin, radial vessels surrounding the lesion, and lesion size discrepancy between contrast-enhanced and conventional sonography were evaluated.

RESULTS

The detection rates for increased size, radial vessels surrounding the lesion, and hyperenhancement on contrast-enhanced sonography were significantly higher in the malignant than the benign group (P < .05). The sensitivity, specificity, and accuracy for increased size were 72.7%, 80.0%, and 78.2%, respectively. The sensitivity, specificity, and accuracy for radial vessels surrounding the lesion were 54.5%, 97.1%, and 87.0%. The sensitivity, specificity, and accuracy for hyperenhancement were 81.8%, 60.0%, and 65.0%. No significant difference was found for the enhancement pattern, direction, and margin between the groups.

CONCLUSIONS

Contrast-enhanced sonographic features of sub-1-cm breast lesions included increased size on contrast-enhanced sonography, radial vessels surrounding the lesion, and hyperenhancement. Identification of these features is useful for differentiation of small breast lesions.

Peripheral enhancement of breast cancers on contrast-enhanced ultrasound: correlation with microvessel density and vascular endothelial growth factor expression

There is little evidence of an association between peripheral enhancement on contrast-enhanced ultrasound and histopathologic prognostic factors in breast cancer. The purpose of our study was to investigate the relationship of peripheral enhancement on contrast-enhanced ultrasound with microvessel density, vascular endothelial growth factor (VEGF) expression and other prognostic factors in patients with breast cancer. In 51 patients with BI-RADS (Breast Imaging Reporting and Data System) category 5 lesions scheduled for surgery, contrast-enhanced ultrasound with an 8-4 linear transducer and B-mode pulse inversion harmonic imaging was performed after administration of SonoVue. Forty-three histologically confirmed breast cancers were included in the study and divided into the peripheral enhancement group and non-peripheral enhancement group on the basis of their features on contrast-enhanced ultrasound. The ratio of peripheral to central microvessel density, VEGF expression, tumor size, histopathologic type, stage, lymph node metastasis and expression of estrogen receptor, progesterone receptor, c-erb-B2 and p53 were compared between the two groups. The ratio of peripheral to central microvessel density and a peripherally positive/centrally negative VEGF expression pattern were significantly higher in the peripheral enhancement group than in the non-peripheral enhancement group (t-test, p = 0.023, and χ(2) test, p = 0.035, respectively). There were no significant differences in breast cancer size, histopathologic type, stage, lymph node metastasis or expression of estrogen receptor, progesterone receptor, c-erb-B2 and p53 between the two groups (χ(2) test, p = 0.416, 0.877, 0.543, 0.124, 0.453, 0.554, 0.350 and 0.479 respectively). The peripheral enhancement pattern of breast cancer on contrast-enhanced ultrasound may be valuable in the evaluation of peripheral/central tumor angiogenesis and VEGF expression.