Correlation of contrast-enhanced ultrasound kinetics with prognostic factors in invasive breast cancer

Contrast-Enhanced Ultrasound and Conventional Ultrasound Characteristics of Breast Cancer With Different Molecular Subtypes

BACKGROUND

Identifying molecular subtypes of breast cancer (BC) is of great significance in selecting optimal treatment strategy. Different molecular subtypes of BC have various vascular distribution characteristics. Contrast-enhanced ultrasound (CEUS) can dynamically display the microcirculation of tumor. This study intends to explore the conventional ultrasound and CEUS characteristics of different molecular subtypes of BC.

METHODS

During this prospective study, 86 patients with BC who were divided into Luminal A (LA), Luminal B (LB), HER2 over-expression (H2), and triple-negative (TN). The CEUS qualitative and quantitative characteristics of BC with different molecular subtypes was explored, as well as the conventional ultrasound features. In addition, the diagnostic efficiency of CEUS quantitative parameters in differentiating molecular subtypes of BC was analyzed.

RESULTS

Our study found that the Adler grade differed significantly among 4 molecular subtypes (P < .05). The enhancement speed, enhancement degree and size after enhancement of 4 molecular subtypes were statistically different (P < .05). The wash in slope (WIS), peak intensity (PI), and wash-in area under the curve (WiAUC) differed significantly among 4 subtypes (P < .05). The diagnostic efficiency of PI was better for detecting LA and H2 subtype with the areas under the receiver operating characteristic curve was 0.778 and 0.734, respectively.

CONCLUSION

Different molecular subtypes of BC have different CEUS and conventional ultrasound characteristics. CEUS can provide valuable imaging basis for precise clinical diagnosis and individualized therapy of BC with different molecular subtypes.

Development and validation of a dynamic nomogram based on conventional ultrasound and contrast-enhanced ultrasound for stratifying the risk of central lymph node metastasis in papillary thyroid carcinoma preoperatively

Purpose

The aim of this study was to develop and validate a dynamic nomogram by combining conventional ultrasound (US) and contrast-enhanced US (CEUS) to preoperatively evaluate the probability of central lymph node metastases (CLNMs) for patients with papillary thyroid carcinoma (PTC).

Methods

A total of 216 patients with PTC confirmed pathologically were included in this retrospective and prospective study, and they were divided into the training and validation cohorts, respectively. Each cohort was divided into the CLNM (+) and CLNM (-) groups. The least absolute shrinkage and selection operator (LASSO) regression method was applied to select the most useful predictive features for CLNM in the training cohort, and these features were incorporated into a multivariate logistic regression analysis to develop the nomogram. The nomogram's discrimination, calibration, and clinical usefulness were assessed in the training and validation cohorts.

Results

In the training and validation cohorts, the dynamic nomogram (https://clnmpredictionmodel.shinyapps.io/PTCCLNM/) had an area under the receiver operator characteristic curve (AUC) of 0.844 (95% CI, 0.755-0.905) and 0.827 (95% CI, 0.747-0.906), respectively. The Hosmer-Lemeshow test and calibration curve showed that the nomogram had good calibration (p = 0.385, p = 0.285). Decision curve analysis (DCA) showed that the nomogram has more predictive value of CLNM than US or CEUS features alone in a wide range of high-risk threshold. A Nomo-score of 0.428 as the cutoff value had a good performance to stratify high-risk and low-risk groups.

Conclusion

A dynamic nomogram combining US and CEUS features can be applied to risk stratification of CLNM in patients with PTC in clinical practice.

Association Between Contrast-Enhanced Ultrasound Characteristics and Molecular Subtypes of Breast Cancer

OBJECTIVE

This study aimed to investigate the correlation between contrast-enhanced ultrasound (CEUS) features and molecular subtypes of breast cancer (BC).

METHODS

A total of 116 patients (116 lesions) with pathologically diagnosed BC who received conventional ultrasound and CEUS before surgery were enrolled in this study. BC molecular subtypes were identified by postoperative pathological and immunohistochemical analysis as Luminal A (LA), Luminal B (LB), HER2 (H2) over-expression, and triple-negative (TN). Qualitative and quantitative CEUS characteristics were analyzed by one-way analysis of variance (continuous variables) or Pearson's χ² test or Fisher's exact probability method (categorical variables).

RESULTS

There were significant differences in enhancement speed and enhancement degree among the four subtypes (P < .05). The area under the curve (AUC), time to peak (TTP), and peak intensity (PI) differed among the four subtypes (P < .05). The AUC of the LA subtype (305.1 ± 188.4) was significantly smaller compared with the H2 (535.7 ± 222.0, P = .007) and TN subtypes (496.6 ± 254.7, P = .019). In addition, TTP was shorter in the H2 subtype (19.8 ± 4.9) compared with the other subtypes, and was significantly shorter than in the LA subtype (26.3 ± 7.2, P = .008) and LB subtype (23.1 ± 6.7, P = .036). The PI of the LA subtype (4.7 ± 2.3) was significantly lower than that of the LB (6.6 ± 2.3, P = .027), H2 (7.4 ± 2.2, P = .005), and TN subtypes (6.9 ± 2.6, P = .014).

CONCLUSIONS

CEUS features differed significantly among different molecular subtypes of BC. The enhancement patterns and parameters may be important predictive features of different subtypes of BC.

Differentiation Between Granulomatous Lobular Mastitis and Breast Cancer Using Quantitative Parameters on Contrast-Enhanced Ultrasound

Objective

To investigate the Contrast-enhanced ultrasound (CEUS) imaging characteristics of granulomatous lobular mastitis (GLM) and the value of differentiating GLM from breast cancer.

Materials and methods

The study included 30 women with GLM (mean age 36.7 ± 5 years [SD]) and 58 women with breast cancer (mean age 48. ± 8 years [SD]) who were scheduled for ultrasound-guided tissue biopsy. All patients were evaluated with conventional US and CEUS prior to the biopsy. In both groups, the parameters of the quantitative and qualitative analysis of the CEUS were recorded and compared. The receiver-operating-characteristics curves (ROC) were created. Sensitivity, specificity, cut-off, and area under the curve (AUC) values were calculated.

Results

TTP values in GLM were statistically higher than in breast cancer (mean, 27.63 ± 7.29 vs. 20.10 ± 6.11), but WIS values were lower (mean, 0.16 ± 0.05 vs. 0.28 ± 0.17). Rich vascularity was discovered in 54.45% of breast cancer patients, but only 30.00% of GLM patients had rich vascularity. The AUC for the ROC test was 0.791 and 0.807, respectively. The optimal cut-off value for TTP was 24.5s, and the WIS cut-off value was 0.185dB/s, yielding 73.33% sensitivity, 84.48% specificity, and 86.21% sensitivity, 70% specificity respectively in the diagnosis of GLM. The lesion scores reduced from 4 to 3 with the addition of CEUS for the patients with GLM. However, the scores did not change for the patients with breast cancer.

Conclusion

CEUS could help distinguish GLM from breast cancer by detecting higher TTP and WIS values, potentially influencing clinical decision-making for additional biopsies.

Effects of contrast-enhanced ultrasound treatment on neoadjuvant chemotherapy in breast cancer

Purpose: Preclinical and clinical data indicate that contrast-enhanced ultrasound can enhance tumor perfusion and vessel permeability, thus, improving chemotherapy accumulation and therapeutic outcome. Therefore, we investigated the effects of high mechanical index (MI) contrast-enhanced Doppler ultrasound (CDUS) on tumor perfusion in breast cancer. Methods: In this prospective study, breast cancer patients were randomly assigned to receive either 18 minutes of high MI CDUS during chemotherapy infusion (n = 6) or chemotherapy alone (n = 5). Tumor perfusion was measured before and after at least six chemotherapy cycles using motion-model ultrasound localization microscopy. Additionally, acute effects of CDUS on vessel perfusion and chemotherapy distribution were evaluated in mice bearing triple-negative breast cancer (TNBC). Results: Morphological and functional vascular characteristics of breast cancer in patients were not significantly influenced by high MI CDUS. However, complete clinical tumor response after neoadjuvant chemotherapy was lower in high MI CDUS-treated (1/6) compared to untreated patients (4/5) and size reduction of high MI CDUS treated tumors tended to be delayed at early chemotherapy cycles. In mice with TNBC high MI CDUS decreased the perfused tumor vessel fraction (p < 0.01) without affecting carboplatin accumulation or distribution. Higher vascular immaturity and lower stromal stabilization may explain the stronger vascular response in murine than human tumors. Conclusion: High MI CDUS had no detectable effect on breast cancer vascularization in patients. In mice, the same high MI CDUS setting did not affect chemotherapy accumulation although strong effects on the tumor vasculature were detected histologically. Thus, sonopermeabilization in human breast cancers might not be effective using high MI CDUS protocols and future applications may rather focus on low MI approaches triggering microbubble oscillations instead of destruction. Furthermore, our results show that there are profound differences in the response of mouse and human tumor vasculature to high MI CDUS, which need to be further explored and considered in clinical translation.

Prospective evaluation of contrast-enhanced ultrasound of breast BI-RADS 3-5 lesions

BACKGROUND

To determine the benefit of contrast-enhanced ultrasound (CEUS) in the assessment of breast lesions.

METHODS

A standardized contrast-enhanced ultrasound was performed in 230 breast lesions classified as BI-RADS category 3 to 5. All lesions were subjected to qualitative and quantitative analysis. MVI (MicroVascular Imaging) technique was used to derive qualitative analysis parameters; blood perfusion of the lesions was assessed (perfusion homogeneity, type of vascularization, enhancement degree). Quantitative analysis was conducted to estimate perfusion changes in the lesions within drawn regions of interest (ROI); parameters TTP (time to peak), PI (peak intensity), WIS (wash in slope), AUC (area under curve) were obtained from time intensity (TI) curves. Acquired data were statistically analyzed to assess the ability of each parameter to differentiate between malignant and benign lesions. The combination of parameters was also evaluated for the possibility of increasing the overall diagnostic accuracy. Biological nature of the lesions was verified by a pathologist. Benign lesions without histopathological verification (BI-RADS 3) were followed up for at least 24 months.

RESULTS

Out of 230 lesions, 146 (64%) were benign, 67 (29%) were malignant, 17 (7%) lesions were eliminated. Malignant tumors showed statistically significantly lower TTP parameters (sensitivity 77.6%, specificity 52.7%) and higher WIS values (sensitivity 74.6%, specificity 66.4%) than benign tumors. Enhancement degree also proved to be statistically well discriminating as 55.2% of malignant lesions had a rich vascularity (sensitivity 89.6% and specificity 48.6%). The combination of quantitative analysis parameters (TTP, WIS) with enhancement degree did not result in higher accuracy in distinguishing between malignant and benign breast lesions.

CONCLUSIONS

We have demonstrated that contrast-enhanced breast ultrasound has the potential to distinguish between malignant and benign lesions. In particular, this method could help to differentiate lesions BI-RADS category 3 and 4 and thus reduce the number of core-cut biopsies performed in benign lesions. Qualitative analysis, despite its subjective element, appeared to be more beneficial. A combination of quantitative and qualitative analysis did not increase the predictive capability of CEUS.

Correlation of contrast-enhanced ultrasound features with prognostic factors in invasive ductal carcinomas of the breast

OBJECTIVES

To correlate contrast-enhanced ultrasound (CEUS) features with pathological prognostic factors of breast invasive ductal carcinomas (IDCs).

METHODS

169 patients who were admitted to our hospital with confirmed IDCs diagnosed between August 2017 and June 2019 were selected. CEUS indicators included the time of contrast agent entered the lesion, the degree of enhancement, the boundary of the lesion, whether there was perfusion defect and nourishing blood vessels, and etc. These parameters correlated with traditional prognostic factors (tumour size, histological grade, axillary lymph node status) and immunohistochemical biomarkers (ER, PR, c-erbB-2, Ki-67, and TOPO-II).

RESULTS

Perfusion defects after enhancement were predictive factors of PR negative expression (r = - 0.318, OR = 0.239) and TOPO-II overexpression (r = 0.284, OR = 3.577). Centripetal enhancement was negatively correlated with ER expression (r = - 0.350, OR = 0.246). The lesions with a larger range after enhancement than the conventional ultrasound had a higher histological grade (r = 0.215). Perfusion defects were positively correlated with lymph node metastasis (r = 0.221) and negatively correlated with the expression of ER and PR (r = - 0.342, r = - 0.318).

CONCLUSIONS

Contrast-enhanced ultrasound features of IDCs have a certain correlation with pathological prognostic factors, which is conducive in assessing the prognosis of these patients.

Diagnostic efficacy of contrast-enhanced ultrasound for breast lesions of different sizes: a comparative study with magnetic resonance imaging

OBJECTIVE

This study aimed to compare the diagnostic performance of contrast-enhanced ultrasound (CEUS), MRI, and the combined use of the two modalities for differentiating breast lesions of different sizes.

METHODS

A total of 406 patients with 406 solid breast masses detected by conventional ultrasound underwent both CEUS and MRI scans. Histological results were used as reference standards. The lesions were categorized into three groups according to size (Group 1, ≤ 20 mm; Group 2, > 20 mm, Group 3: total lesions). Sensitivity, specificity, accuracy, and receiver operating characteristic (ROC) curve analysis were used to assess the diagnostic performance of these imaging methods for breast lesions.

RESULTS

There were 194 benign and 212 malignant breast lesions according to the histological diagnosis. Compared with MRI, CEUS demonstrated similar sensitivity in detecting breast cancer (p = 1.0000 for all) in all the three groups. With regard to specificity, accuracy, and the area under the ROC curve (Az) values, MRI showed a better performance than that shown by CEUS (p ＜0.05 for all), and the combination of the two modalities improved the diagnostic performance of CEUS alone significantly (p ＜0.05 for all) in all the three groups. However, the diagnostic specificity and accuracy of the combined method was not superior to that of MRI alone except for Group 2.

CONCLUSION

CEUS demonstrated good sensitivity in detecting breast cancer, and the combined use with MRI can optimize the diagnostic specificity and accuracy in breast cancer prediction.

ADVANCES IN KNOWLEDGE

Few studies have compared the diagnostic efficacy of CEUS and MRI, and this study is the first attempt to seek out the diagnostic values for breast lesions of variable sizes (lesions with ≤20 mm and >20 mm).

Contrast-Enhanced Ultrasound Imaging of Breast Masses: Adjunct Tool to Decrease the Number of False-Positive Biopsy Results

OBJECTIVES

This pilot study evaluated use of contrast-enhanced ultrasound (CEUS) to reduce the number of benign breast masses recommended for biopsy.

METHODS

This prospective study included 131 consenting women, from October 2016 to June 2017, with American College of Radiology Breast Imaging Reporting and Data System category 4a, 4b, and 4c masses detected by mammography, conventional ultrasound (US), or both. Contrast-enhanced US examinations (using intravenous injection of perflutren lipid microspheres or sulfur hexafluoride lipid-type A microspheres) were performed before biopsy. Qualitative and quantitative CEUS parameters were compared with reference standard histopathologic results from biopsy of 131 masses.

RESULTS

There were 109 benign, 6 high-risk, and 16 malignant masses, with a median size of 12 mm (range, 4 to 48 mm) on conventional US imaging. Of 131 masses, 93 (71%) enhanced on CEUS imaging, including 73 of 109 (67%) benign, 6 of 6 (100%) high-risk, and 14 of 16 (87.5%) malignant. Thirty-eight lesions did not enhance, including 36 of 109 (33%) benign and 2 of 16 (12.5%) malignant. Prediction models using recursive petitioning revealed that CEUS may reduce 31% (95% confidence interval, 23%, 40%) of benign biopsies for masses that are: nonenhancing with circumscribed margins or enhancing with an oval shape and homogeneous enhancement. Quantitative parameters indicated that benign masses had the longest time to peak (P = .078), highest time-to-peak ratio of mass to background (P = .036), lowest peak intensity (P = .021), and smallest difference in peak intensity between the mass and background (P = .079) compared to high-risk and malignant lesions.

CONCLUSIONS

Contrast-enhanced US may be a valuable modality that can be used to predict benign pathologic results of breast masses, thereby reducing the number of biopsies.

A multi-model framework to estimate perfusion parameters using contrast-enhanced ultrasound imaging

PURPOSE

Contrast-enhanced ultrasound imaging has expanded the diagnostic potential of ultrasound by enabling real-time imaging and quantification of tissue perfusion. Several perfusion models and curve fitting methods have been developed to quantify the temporal behavior of tracer signal and standardize perfusion quantification. While the least-squares approach has traditionally been applied for curve fitting, it can be inadequate for noisy and complex data. Moreover, previous research suggests that certain perfusion models may be more relevant depending on the organ or tissue imaged. We propose a multi-model framework to select the most appropriate perfusion model and curve fitting method for each diagnostic application.

METHODS

Our multi-model approach uses a system identification method, which estimates perfusion parameters from the model with the best fit to a given time-intensity curve. We compared current perfusion quantification methods that use a single perfusion model and curve fitting method and our proposed multi-model framework on bolus 3D dynamic contrast-enhanced ultrasound (DCE-US) in vivo images obtained in mice implanted with a colon cancer, as well as on simulation data. The quality of fit in estimating perfusion parameters was evaluated using the Spearman correlation coefficient, the coefficient of determination (R² ), and the normalized root-mean-square error (NRMSE) to ensure that the multi-model framework finds the best perfusion model and curve fitting algorithm.

RESULTS

Our multi-model framework outperforms conventional single perfusion model approaches with least-squares optimization, providing more robust perfusion parameter estimation. R² and NRMSE are 0.98 and 0.18, respectively, for our proposed method. By comparison, the performance of the traditional approach is much more dependent upon the selection of the appropriate model. The R² and NRMSE are 0.91 and 0.31, respectively.

CONCLUSIONS

The proposed multi-model framework for perfusion modeling outperforms the current approach of single perfusion modeling using least-squares optimization and more robustly estimates perfusion parameters when using empiric data labeled by an expert as the gold standard. Our technique is minimally sensitive to issues affecting the accuracy of perfusion parameter estimation, including rise time, noise, region of interest size, and frame rate. This framework could be of key utility in modeling different perfusion systems in different tissues and organs.

Perfusion contrast-enhanced ultrasound to predict early lymph-node metastasis in breast cancer

PURPOSE

To evaluate whether quantitative analysis of perfusion contrast-enhanced ultrasound (CE-US) could predict early lymph-node (LN) metastasis in clinically node-negative breast cancer.

MATERIALS AND METHODS

In this prospective study, 64 breast cancer patients were selected for perfusion CE-US imaging. Regions of interest were placed where the strongest and weakest signal increases were found to obtain peak intensities (PIs; PI_max and PI_min, respectively) for time-intensity curve analyzes. The PI difference and PI ratio were calculated as follows: PI difference = PI_max-PI_min; PI ratio = PI_max/PI_min.

RESULTS

Forty-seven cases were histologically diagnosed as negative for LN metastasis and 17 were positive. There was a significant difference in PI_min and the PI ratio between the LN-negative and -positive metastasis groups (p = 0.0053 and 0.0082, respectively). Receiver-operating curve analysis revealed that the area under the curve of PI_min and the PI ratio were 0.73 and 0.72, respectively. The most effective threshold for the PI ratio was 1.52, and the sensitivity, specificity, positive predictive value, and negative predictive value were 59% (10/17), 87% (41/47), 63% (10/16), and 85% (41/48), respectively.

CONCLUSIONS

Parameters from the quantitative analysis of perfusion CE-US imaging showed significant differences between the LN-negative and -positive metastasis groups in clinically node-negative breast cancer.

Correlation Between Contrast-enhanced Ultrasound Characteristics (Qualitative and Quantitative) and Pathological Prognostic Factors in Breast Cancer

BACKGROUND/AIM

Little is known about the correlation between contrast-enhanced ultrasound (CEUS) characteristics and pathological prognostic factors in breast cancer. The aim of this study was to explore the correlation between CEUS characteristics and pathological prognostic factors.

PATIENTS AND METHODS

A retrospective study with 34 malignant breast lesions was conducted. CEUS characteristics included qualitative characteristics (e.g. lesion's enhancement degree and order, internal lesion homogeneity etc.) and quantitative characteristics (e.g. peak intensity, time to peak etc.). Also, pathological prognostic factors were included (e.g. tumor grade, estrogen receptor status etc.).

RESULTS

Blurred lesion margins were observed more often in tumors of high histological grade (p=0.01) and in estrogen receptor-negative tumors (p=0.049). Furthermore, perilesional enhancement was associated with positive Ki-67 expression (p=0.049), while heterogeneous internal sentinel lymph node enhancement was associated with malignant infiltration of the node (p=0.002).

CONCLUSION

CEUS has the potential to provide a prevision of pathological prognostic factors in malignant breast lesions, helping in the better early patient management.

Diagnostic and prognostic values of contrast‑enhanced ultrasound combined with diffusion‑weighted magnetic resonance imaging in different subtypes of breast cancer

The present study aimed to investigate the diagnostic and prognostic values of contrast-enhanced ultrasound (CEUS) combined with diffusion-weighted magnetic resonance imaging (DW-MRI) in different subtypes of breast cancer (BC). CEUS and DW-MRI were conducted in 232 patients with BC prior to surgical treatment. Patients were categorized as having the luminal A subtype, the luminal B subtype, triple-negative subtype or the human epidermal growth factor receptor 2 (Her-2)-positive subtype according to their expression of the estrogen receptor (ER), progesterone receptor (PR) and Her-2, as detected by immunohistochemistry. The CEUS and DW-MRI parameters of patients with different subtypes of BC were obtained and analyzed. The risk factors for the prognosis of patients with different subtypes of BC were analyzed using Kaplan-Meier and COX regression analyses. The diagnostic accuracy rate of CEUS combined with DW-MRI (93.10%) was higher than that of CEUS (88.79%) or DW-MRI (82.33%) alone. The local recurrence rate and distant metastasis rate of the Her-2-positive subtype were the highest among all the subtypes. Furthermore, patients with Her-2-positive BC exhibited a higher proportion of lesions with indistinct margins and histological grade III. Lymph node metastasis and BC subtype were independent risk factors for the prognosis of BC. The overall survival and disease-free survival of patients with the luminal A subtype were higher than those of patients with the Her-2-positive subtype. The results of the current study therefore indicate that CEUS combined with DW-MRI is more effective at diagnosing the different subtypes of BC than either CEUS or DW-MRI alone.

Accuracy of four ultrasonography techniques in predicting histopathological classification of canine mammary carcinomas

Due to the importance of presurgical, noninvasive, and accurate diagnostic tools in mammary carcinoma characterization, this prospective secondary observational cohort study was designed to evaluate and compare the diagnostic accuracy of B-mode, Doppler, contrast enhancement ultrasonography, or acoustic radiation force impulse-elastography in identifying mammary carcinomas types with high degree of malignancy. A total of 246 mammary carcinomas from 141 female dogs were analyzed using B-mode, Doppler, contrast enhancement ultrasonography, and acoustic radiation force impulse ultrasonography prior to their histopathological classification according to types (simple, complex, or special) and grade (I, II, or III). Qualitative and quantitative variables were compared between carcinoma types and grades by Fisher's or analysis of variance. Diagnostic performance was estimated by receiver-operating characteristic analysis, using histopathological classification as a reference. Deformability (acoustic radiation force impulse) had a diagnostic specificity of 100% and sensitivity of 12% in identifying special carcinomas. A width:length ratio greater than 0.53 can be suggestive of special carcinoma, with 80% sensitivity and 76% specificity. Contrast wash-in and peak enhancement times lower than 7.5 and 13.5 s, respectively, were indicative of complex carcinoma at 62% sensitivity and 60% specificity. Contrast wash-in, peak enhancement, and wash-out times greater than 6.5, 12.5, and 64.5 s, respectively; were indicative of grade II and III carcinoma at 68% sensitivity and 62% specificity. In conclusion, B-mode ultrasonography, contrast enhancement ultrasonography, and acoustic radiation force impulse-elastography enabled the identification of some of the characteristics of high-grade mammary carcinoma types and grades in female dogs with limited accuracy. The findings from this study may contribute to oncology research and clinical management canine patients.

Utility of quantitative contrast-enhanced ultrasound for the prediction of extracapsular extension in papillary thyroid carcinoma

The aim of this study was to find an accurate method for the detection of extracapsular extension (ECE) in papillary thyroid carcinoma (PTC). A total of 102 patients with 109 PTC nodules were retrospectively enrolled. Contrast-enhanced ultrasound (CEUS) characteristics were evaluated. The diagnostic efficacy of quantitative CEUS and tumor size was analyzed. The qualitative CEUS features did not differ significantly between the ECE and non-ECE groups (P > 0.05). All of the quantitative CEUS parameters with the exception of peak intensity and tumor size were found to differ significantly between the ECE and non-ECE groups (P < 0.05). Multivariate stepwise logistic regression analysis demonstrated that time from peak to one half (TPH), tumor size and wash-in slope (WIS) were the significantly different parameters between the ECE and non-ECE groups (P = 0.000, P = 0.005 and P = 0.030, respectively).The sensitivity and specificity in the diagnosis of ECE were: TPH, 75.4% (43/57) and 78.9% (41/52), respectively; WIS, 87.7% (50/57) and 42.3% (22/52), respectively; and tumor size, 71.9% (41/57) and 65.4% (34/52), respectively. Quantitative CEUS analysis and tumor size are essential for the prediction of ECE in PTC; in particular TPH has good diagnostic value in detecting ECE. Our study provides important insights into the prediction of ECE in PTC.

Quantitative Analysis of Contrast-Enhanced Ultrasound Imaging in Invasive Breast Cancer: A Novel Technique to Obtain Histopathologic Information of Microvessel Density

We examined whether enhancement area ratios obtained by the new bubble detection method correlate with histologic microvessel density in invasive breast cancer. Forty consecutive patients with invasive breast cancer lesions underwent contrast-enhanced ultrasound. The ratio of enhanced area to manually segmented tumor area (enhancement area ratio) was obtained with the new method at peak and delayed phases (50-54, 55-59, 60-64 and 65-69 s). We also analyzed time-intensity curves to obtain peak intensity and area under curve. Enhancement area ratios in both peak and delayed phases (50-54, 55-59, 60-64 and 65-69 s) were significantly correlated with microvessel density (r = 0.57, 0.62, 0.68, 0.61 and 0.58; p = 0.0001, <0.0001, <.0001, <.0001 and 0.0001, respectively). In time-intensity curve analysis, peak intensity was significantly correlated (r = 0.43, p = 0.0073), whereas area under the curve was not (r = 0.29, p = 0.0769). Enhancement area ratios obtained by the new method were correlated with microvessel density in invasive breast cancer.

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.

Contrast-Enhanced Ultrasonography Features of Breast Malignancies with Different Sizes: Correlation with Prognostic Factors

This study was to investigate the correlation between contrast-enhanced ultrasonography (CEUS) characteristics with prognostic factors in breast cancers with different sizes. A retrospective analysis of CEUS characteristics of 104 pathologically proven malignant lesions from 104 women was conducted. Lesions were divided into two groups according to their size measured by US (Group 1: maximum diameter ≤20 mm; Group 2: maximum diameter >20 mm). Features including enhancement degree, order and pattern, enlargement of the enhancement area, and penetrating vessels on CEUS were evaluated. Pathologic prognostic factors, including estrogen and progesterone receptor status, and the expression of c-erb-B2, p53, Ki-67, and VEGF were assessed. Comparison of enhancement pattern parameters between Group 1 and Group 2 showed statistically significant differences (P < 0.0001). A significant correlation was found between enlargement of the enhancement area and ER positivity in Group 1 (P = 0.032). In Group 2 the absence of penetrating vessels was significantly associated with VEGF negativity (P = 0.022) and ER negativity (P = 0.022). Centripetal enhancement reflected VEGF negativity (P = 0.033) in lesions with diameter >20 mm. Thus, breast cancers with different sizes show different CEUS features; small breast cancers show homogeneous enhancement pattern while cancers with diameter >20 mm show homogeneous enhancement pattern. Some CEUS characteristics of differently sized breast cancers could be correlated with prognostic factors, which may be useful in prognosis assessment.

Qualitative, quantitative and combination score systems in differential diagnosis of breast lesions by contrast-enhanced ultrasound

OBJECTIVE

To assess the feasibility of score systems in differential diagnosis of breast lesions by contrast-enhanced ultrasound (CEUS).

METHODS

CEUS was performed in 121 patients with 127 breast lesions by Philips iU22 with Sonovue as contrast agent. Pearson Chi-square χ(2) test, binary logistic regression analysis and Student's t-test are used to identify significant CEUS parameters in differential diagnosis. Based on these significant CEUS parameters, qualitative, quantitative and combination score systems were built by scoring 1 for benign characteristic and scoring 2 for malignant characteristic. Receiver operating characteristic (ROC) curve was applied to evaluate the diagnostic efficacy of different analytical methods.

RESULTS

Pathological results showed 41 benign and 86 malignant lesions. Qualitative analysis and logistic regression analysis showed that there are significant differences in enhancement degree, enhancement order, internal homogeneity, enhancement margin, surrounding vessels and enlargement of diameters (P<0.05) between benign and malignant lesions. Quantitative analysis indicated that malignant lesions tended to show higher peak intensity (PI), larger area under the curve (AUC) and shorter time to peak (TTP) than benign ones (P<0.05). Qualitative score systems showed higher diagnostic efficacy than single quantitative CEUS parameters. The corresponding area under the ROC curve for qualitative, quantitative and combination score systems were 0.897, 0.716 and 0.903 respectively. Z test showed that area under the ROC curve of quantitative score system was statistically smaller than that of other score systems.

CONCLUSIONS

Quantitative score system helps little in improving the diagnostic efficacy of CEUS. While qualitative score system improves the performance of CEUS greatly in discrimination of benign and malignant breast lesions. The application of qualitative could develop the diagnostic performance of CEUS which is clinically promising.

Prognostic importance of ultrasound BI-RADS classification in breast cancer patients

OBJECTIVE

We investigated the prognostic importance of pre-operative Breast Imaging Reporting and Data System classification in ultrasound imaging.

METHODS

Histopathological differences and disease-free survival were analyzed in Breast Imaging Reporting and Data System classification subgroups. Univariate and multivariate analyses were used to identify the prognostic factors.

RESULTS

We identified 531 invasive breast cancer patients eligible for this study. Most patients classified as Breast Imaging Reporting and Data System 5 had large tumors and a higher rate of lymph node metastasis. However, hormonal receptor or HER-2 status did not differ according to Breast Imaging Reporting and Data System classification. During a median post-operative follow-up of 42.0 months, 43 patients were diagnosed with a disease-specific event. Disease-free survival was significantly lower in patients with Breast Imaging Reporting and Data System 5 than in patients with Breast Imaging Reporting and Data System 3-4. Subgroup analysis of patients with invasive breast cancer of Stage I showed that Breast Imaging Reporting and Data System 5 was an independent negative prognostic indicator of disease-free survival (hazard ratio 9.195; 95% confidence interval, 1.175-71.955; P = 0.035).

CONCLUSIONS

Breast Imaging Reporting and Data System classification might be considered as prognostic factors especially in Stage I breast cancer. Further confirmatory studies are needed.

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.