Diagnostic accuracy of contrast-enhanced ultrasound synchronized with shear wave elastography in the differential diagnosis of benign and malignant breast lesions: a diagnostic test

Abstract

Background: Breast cancer (BC) is one of the most common malignancies affecting women. Timely and accurate diagnosis is crucial for treatment and prognosis. Some studies have found that elastography combined with microperfusion characteristics, which are mostly described by contrast-enhanced ultrasound (CEUS), could help in the diagnosis of breast lesions. This study aimed to assess the diagnostic performance of CEUS synchronized with shear wave elastography (SWE) in discriminating between benign and malignant breast lesions by using real-time contrast elastography images to analyze shell elasticity and contrast intensity.

Methods: A total of 26 pathologically confirmed breast lesions in 26 patients were retrospectively reviewed. Each patient underwent conventional B-mode ultrasound, CEUS, and then SWE data was obtained from a frame of image that was almost identical to the B-mode and CEUS images when acquiring time to peak (TTP). Breast lesions were evaluated based on the Breast Imaging Reporting and Data System (BI-RADS) and quantitative characteristics that describe the stiffness and intensity of contrast of the 1.0-3.0 mm shell region. Quantitative aspects of the inner lesions and shell on the elastogram included the maximum (Emax), mean (Emean), and minimum (Emin) Young's moduli. Quantitative enhanced features included maximum (Imax) and mean (Imean) intensity. We took postoperative pathological results as the gold standard. Receiver operating characteristic (ROC) curves were used to compare the diagnostic efficacy of the 2 examination modalities, either alone or in combination.

Results: The age of the patients ranged from 23 to 76 years, with a 42.5-year average age. In all breast lesions, 19 were benign and 7 were malignant. SWE synchronized with CEUS can effectively improve the diagnostic performance of breast lesions, and Emean + Imean and Emax + Emean + Imean of shell at 1.0 mm both had the highest area under the curve (AUC) of 0.86 [95% confidence interval (CI): 0.67, 0.96], with the sensitivity and specificity of 71.43% and 89.47%, respectively.

Conclusions: The combination of CEUS and SWE has a better diagnostic value in differentiating benign and malignant breast lesions compared to separate techniques.

Keywords: Breast; contrast-enhanced ultrasound (CEUS); shear wave elastography (SWE); ultrasonography (US).

Figure 1

Flowchart illustrating the study process. US, ultrasound; CEUS, contrast-enhanced ultrasound; SWE, shear wave elastography; BI-RADS, Breast Imaging Reporting and Data System.

Figure 2

53-year-old woman with fibroadenoma. (A) ROI for quantitative analysis of CEUS. (B) Quantitative analysis of TIC of CEUS, which showed the TTP was 36.07 s. (C) CEUS synchronized with SWE quality control with no obvious artifacts. (D) The shell included 1.0 mm peripheral tissue surrounding the breast lesion. The values of Emax, Emean, Emin, Imax, and Imean were 23.70 kPa, 10.62 kPa, 4.04 kPa, 34.26 dB, and 7.31 dB, respectively. (E) The shell included 2.0 mm peripheral tissue surrounding the breast lesion. The values of Emax, Emean, Emin, Imax, and Imean were 34.31 kPa, 10.95 kPa, 4.04 kPa, 37.27 dB, and 7.92 dB, respectively. (F) The shell included 3.0 mm peripheral tissue surrounding the breast lesion. The values of Emax, Emean, Emin, Imax, and Imean were 36.77 kPa, 10.84 kPa, 4.04 kPa, 38.02 dB, and 7.71 dB, respectively. ROI, region of interest; CEUS, contrast-enhanced ultrasound; TIC, time-intensity curve; TTP, time to peak; SWE, shear wave elastography; Emax, the maximum Young’s moduli; Emean, the mean Young’s moduli; Emin, the minimum Young’s moduli; Imax, the maximum intensity; Imean, the mean intensity.

Figure 3

36-year-old woman with invasive lobular carcinoma. (A) ROI for quantitative analysis of CEUS. (B) Quantitative analysis of TIC of CEUS, which showed the TTP was 26.00 s. (C) CEUS synchronized with SWE quality control with no obvious artifacts. (D) The shell included 1.0 mm peripheral tissue surrounding the breast lesion. The values of Emax, Emean, Emin, Imax, and Imean were 150.09 kPa, 44.71 kPa, 10.26 kPa, 50.45 dB, and 21.65 dB, respectively. (E) The shell included 2.0 mm peripheral tissue surrounding the breast lesion. The values of Emax, Emean, Emin, Imax, and Imean were 177.15 kPa, 43.01 kPa, 5.69 kPa, 51.95 dB, and 19.88 dB, respectively. (F) The shell included 3.0 mm peripheral tissue surrounding the breast lesion. The values of Emax, Emean, Emin, Imax, and Imean were 177.15 kPa, 41.00 kPa, 4.39 kPa, 51.95 dB, and 18.37 dB, respectively. ROI, region of interest; CEUS, contrast-enhanced ultrasound; TIC, time-intensity curve; TTP, time to peak; SWE, shear wave elastography; Emax, the maximum Young’s moduli; Emean, the mean Young’s moduli; Emin, the minimum Young’s moduli; Imax, the maximum intensity; Imean, the mean intensity.

Figure 4

ROCs of the CEUS, and CEUS synchronized with SWE when shell was at 1.0 mm and AUC values for analyzing diagnostic performance. The AUC of Imean, Emax + Imean, Emean + Imean, Emax + Emean + Imean were 0.81 (95% CI: 0.61–0.94), 0.86 (95% CI: 0.67–0.96), 0.85 (95% CI: 0.66–0.96), 0.86 (95% CI: 0.67–0.96). ROC, receiver operating characteristic; CEUS, contrast-enhanced ultrasound; SWE, shear wave elastography; AUC, area under the curve; Emax, the maximum Young’s moduli; Imean, the mean intensity; Emean, the mean Young’s moduli; CI, confidence interval.