Correlation of real-time gray scale contrast-enhanced ultrasonography with microvessel density and vascular endothelial growth factor expression for assessment of angiogenesis in breast lesions

Prospects of perfusion contrast-enhanced ultrasound (CE-US) in diagnosing axillary lymph node metastases in breast cancer: a comparison with lymphatic CE-US

Accurate diagnosis of lymph node (LN) metastasis is vital for prognosis and treatment in patients with breast cancer. Imaging 1modalities such as ultrasound (US), MRI, CT, and 18F-FDG PET/CT are used for preoperative assessment. While conventional US is commonly recommended due to its resolution and sensitivity, it has limitations such as operator subjectivity and difficulty detecting small metastases. This review shows the microanatomy of axillary LNs to enhance accurate diagnosis and the characteristics of contrast-enhanced US (CE-US), which utilizes intravascular microbubble contrast agents, making it ideal for vascular imaging. A significant focus of this review is on distinguishing between two types of CE-US techniques for axillary LN evaluation: perfusion CE-US and lymphatic CE-US. Perfusion CE-US is used to assess LN metastasis via transvenous contrast agent administration, while lymphatic CE-US is used to identify sentinel LNs and diagnose LN metastasis through percutaneous contrast agent administration. This review also highlights the need for future research to clarify the distinction between studies involving "apparently enlarged LNs" and "clinical node-negative" cases in perfusion CE-US research. Such research standardization is essential to ensure accurate diagnostic performance in various clinical studies. Future studies should aim to standardize CE-US methods for improved LN metastasis diagnosis, not only in breast cancer but also across various malignancies.

Prediction of Microinvasion in Breast Ductal Carcinoma in Situ Using Conventional Ultrasound Combined with Contrast-Enhanced Ultrasound Features: A Two-Center Study

BACKGROUND

To develop and validate a model based on conventional ultrasound (CUS) and contrast-enhanced ultrasound (CEUS) features to preoperatively predict microinvasion in breast ductal carcinoma in situ (DCIS).

PATIENTS AND METHODS

Data from 163 patients with DCIS who underwent CUS and CEUS from the internal hospital was retrospectively collected and randomly apportioned into training and internal validation sets in a ratio of 7:3. External validation set included 56 patients with DCIS from the external hospital. Univariate and multivariate logistic regression analysis were performed to determine the independent risk factors associated with microinvasion. These factors were used to develop predictive models. The performance was evaluated through calibration, discrimination, and clinical utility.

RESULTS

Multivariate analysis indicated that centripetal enhancement direction (odds ratio [OR], 13.268; 95% confidence interval [CI], 3.687-47.746) and enhancement range enlarged on CEUS (OR, 4.876; 95% CI, 1.470-16.181), lesion size of ≥20 mm (OR, 3.265; 95% CI, 1.230-8.669) and calcification detected on CUS (OR, 5.174; 95% CI, 1.903-14.066) were independent risk factors associated with microinvasion. The nomogram incorporated the CUS and CEUS features achieved favorable discrimination (AUCs of 0.850, 0.848, and 0.879 for the training, internal and external validation datasets), with good calibration. The nomogram outperformed the CUS model and CEUS model (all P < .05). Decision curve analysis confirmed that the predictive nomogram was clinically useful.

CONCLUSION

The nomogram based on CUS and CEUS features showed promising predictive value for the preoperative identification of microinvasion in patients with DCIS.

The discriminatory diagnostic value of multimodal ultrasound combined with blood cell analysis for granulomatous lobular mastitis and invasive ductal carcinoma of the breast

OBJECTIVE

To explore the discriminatory diagnostic value of multimodal ultrasound(US) combined with blood cell analysis (BCA) for Granulomatous Lobular Mastitis (GLM) and Invasive Ductal Carcinoma (IDC) of the breast.

METHODS

A total of 157 breast disease patients were collected and divided into two groups based on postoperative pathological results: the GLM group (57 cases with 57 lesions) and the IDC group (100 cases with 100 lesions). Differences in multimodal ultrasound features and the presence of BCA were compared between the two groups. The receiver operating characteristic (ROC) curve was used to calculate the optimal cutoff values, sensitivity, specificity, 95% confidence interval (CI), and the area under the curve (AUC) for patient age, lesion size, lesion resistive index (RI), and white blood cell (WBC) count in BCA. Sensitivity, specificity, positive predictive value, negative predictive value, diagnostic accuracy, and AUC were calculated for different diagnostic methods.

RESULTS

There were statistically significant differences (P < 0.05) observed between GLM and IDC patients in terms of age, breast pain, the factors in Conventional US (lesion size, RI, nipple delineation, solitary/multiple lesions, margin, liquefaction area, growth direction, microcalcifications, posterior echogenicity and abnormal axillary lymph nodes), the factors in CEUS (contrast agent enhancement intensity, enhancement pattern, enhancement range, and crab-like enhancement) and the factors in BCA (white blood cells, neutrophils, lymphocytes and monocytes). ROC curve analysis results showed that the optimal cutoff values for distinguishing GLM from IDC were 40.5 years for age, 7.15 cm for lesion size, 0.655 for lesion RI, and 10.525*109/L for white blood cells. The diagnostic accuracy of conventional US combined with CEUS (US-CEUS) was the highest (97.45%). The diagnostic performance AUCs for US-CEUS, CEUS, and US were 0.965, 0.921 and 0.832, respectively.

CONCLUSION

Multifactorial analysis of multimodal ultrasound features and BCA had high clinical application value in the differential diagnosis of GLM and IDC.

Association of angiotensin II and receptors in peri-implantation endometrium with microvessel density and pregnancy outcomes of women with recurrent implantation failure after embryo transfer

Purpose

Investigate whether local angiotensin II (AngII) and its AngII type 1 and 2 receptors (AT1R, AT2R) in the endometrium are different and correlate with microvessel density in women with reproductive failure and pregnancy outcomes.

Methods

Endometrium during the window of implantation from 40 women with recurrent miscarriage (RM) and 40 with recurrent implantation failure (RIF) were compared with 27 fertile women. Peri-implantation endometrium from 54 women prior to euploid embryo transfer were collected and compared in women with successful pregnancy and unsuccessful pregnancy.

Results

Compared with fertile women, expression of AT2R was significantly lower, while AT1R/AT2R expression ratio was significantly higher in the stroma of the RIF group. Endometrium arteriole MVD was significantly lower and negatively correlated with the AT1R/AT2R expression ratio in the stroma of the RIF group. No significant differences and correlations were found in the RM group. Compared with the pregnancy group, expression of AT1R and AT2R were significantly lower in all compartments, but only AT1R/AT2R ratio was significantly higher in the stroma of the non-pregnancy group. Similarly, endometrium arteriole MVD was also significantly lower and negatively correlated with the AT1R/AT2R ratio in the stroma of the non-pregnancy group.

Conclusion

Local renin-angiotensin system is dysregulated in peri-implantation endometrium and associated with abnormal angiogenesis in RIF and poor implantation outcome after embryo transfer.

Contrast-Enhanced Ultrasonography (CEUS) in Imaging of the Reproductive System in Dogs: A Literature Review

The use of contrast-enhanced ultrasound (CEUS) has been widely reported for reproductive imaging in humans and animals. This review aims to analyze the utility of CEUS in characterizing canine reproductive physiology and pathologies. In September 2022, a search for articles about CEUS in canine testicles, prostate, uterus, placenta, and mammary glands was conducted on PubMed and Scopus from 1990 to 2022, showing 36 total results. CEUS differentiated testicular abnormalities and neoplastic lesions, but it could not characterize tumors. In prostatic diseases, CEUS in dogs was widely studied in animal models for prostatic cancer treatment. In veterinary medicine, this diagnostic tool could distinguish prostatic adenocarcinomas. In ovaries, CEUS differentiated the follicular phases. In CEH-pyometra syndrome, it showed a different enhancement between endometrium and cysts, and highlighted angiogenesis. CEUS was shown to be safe in pregnant dogs and was able to assess normal and abnormal fetal-maternal blood flow and placental dysfunction. In normal mammary glands, CEUS showed vascularization only in diestrus, with differences between mammary glands. CEUS was not specific for neoplastic versus non-neoplastic masses and for benign tumors, except for complex carcinomas and neoplastic vascularization. Works on CEUS showed its usefulness in a wide spectrum of pathologies of this non-invasive, reliable diagnostic procedure.

Correlation between conventional ultrasound features combined with contrast-enhanced ultrasound patterns and pathological prognostic factors in malignant non-mass breast lesions

OBJECTIVE

To investigate the correlation between ultrasound performance and prognostic factors in malignant non-mass breast lesions (NMLs).

MATERIALS AND METHODS

This study included 106 malignant NMLs in 104 patients. Different US features and contrast enhancement patterns were evaluated. Prognostic factors, including histological types and grades, axillary lymph node and peritumoral lymphovascular status, estrogen and progesterone receptor status and the expression of HER-2 and Ki-67 were determined. A chi-square test and logistic regression analysis were used to analyse possible associations.

RESULTS

Lesion size (OR: 3.08, p = 0.033) and posterior echo attenuation (OR: 8.38, p < 0.001) were useful in reflecting malignant NMLs containing an invasive carcinoma component. Posterior echo attenuation (OR: 7.51, p = 0.003) and unclear enhancement margin (OR: 6.50, p = 0.018) were often found in tumors with axillary lymph node metastases. Peritumoural lymphovascular invasion mostly exhibited posterior echo attenuation (OR: 3.84, p = 0.049) and unclear enhancement margin (OR: 8.68, p = 0.042) on ultrasound images. Perfusion defect was a comparatively accurate enhancement indicator for negative ER (OR: 2.57, p = 0.041) and PR (OR: 3.04, p = 0.008) expression. Calcifications (OR: 3.03, p = 0.025) and enlarged enhancement area (OR: 5.36, p = 0.033) imply an increased risk of positive HER-2 expression. Similarly, Calcifications (OR: 4.13, p = 0.003) and enlarged enhancement area (OR: 11.05, p < 0.001) were valid predictors of high Ki-67 proliferation index.

CONCLUSION

Ultrasound performance is valuable for non-invasive prediction of prognostic factors in malignant NMLs.

Can the delayed phase of quantitative contrast-enhanced mammography improve the diagnostic performance on breast masses?

Background

Contrast-enhanced mammography (CEM) is an imaging tool for breast cancer detection. Most quantitative analyses of CEM involve two phases, and it is unknown whether an added delayed phase can improve its diagnostic performance compared to dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). This study aimed to evaluate whether the delayed phase improves the diagnostic performance of CEM in distinguishing malignant and benign masses.

Methods

This prospective study enrolled 111 women with 111 pathologically confirmed breast masses. CEM was performed after the injection of contrast agent between 2-3 minutes (T1, early phase), 4-5 minutes (T2, second phase), and 7-9 minutes (T3, delayed phase). The quantitative enhanced gray value of lesions (LGV) and the lesion to background grey value ratio (LBR) were measured within each phase's corresponding region of interest (ROI). Based on their changes, the kinetic enhancement pattern was assessed among the three phases, and the diagnostic performance was subsequently measured.

Results

The LGV and LBR of malignant masses were significantly greater than those of benign lesions. The diagnostic performance of LGV and LBR at the delayed phase was consistent with that of the second phase but poorer than that of the early phase. The sensitivity of LGV_T1 + LGV_T2 + LGV_T3 was less than that of LGV_T1 + LGV_T2 (86.5% vs. 95.1%) with a similar area under the curve (AUC), specificity, positive-predictive value (PPV), negative-predictive value (NPV), and accuracy. The sensitivity of LBR_T1 + LBR_T2 + LBR_T3 increased by 19.6%, and specificity decreased by 20.7% compared with LBR_T1 + LBR_T2. The LGV_T1 + LGV_T2 + LGV_T3 + kinetic enhancement (T1-T3) had the lowest sensitivity (67.0%), but the highest specificity (75.8%), and the sensitivity of LBR_T1 + LBR_T2 + LBR_T3 + kinetic enhancement (T1-T3) was higher than that of LBR_T1 + LBR_T2 + kinetic enhancement (T1-T2) (90.2% vs. 63.4%, respectively).

Conclusions

The addition of a delayed CEM phase for breast cancer diagnosis yielded limited performance improvement. The quantitative analysis combined with enhancement patterns between the two consecutive phases has great potential to distinguish between malignant and benign lesions.

The role of contrast-enhanced ultrasound in the diagnosis of malignant non-mass breast lesions and exploration of diagnostic criteria

OBJECTIVES

To assess the value of contrast-enhanced ultrasound (CEUS) for diagnosing malignant non-mass breast lesions (NMLs) and to explore the CEUS diagnostic criteria.

METHODS

A total of 116 patients with 119 NMLs detected by conventional US were enrolled. Histopathological results were used as the reference standard. The enhancement characteristics of NMLs in CEUS were compared between malignant and benign NMLs. The CEUS diagnostic criteria for malignant NMLs were established using independent diagnostic indicators identified by binary logistic regression analysis. The diagnostic performance of Breast Imaging Reporting and Data System-US (BI-RADS-US), CEUS, and BI-RADS-US combined with CEUS was evaluated and compared.

RESULTS

Histopathological results showed 63 and 56 benign and malignant NMLs. Enhancement degree (OR = 5.75, p = 0.003), enhancement area (OR = 4.25, p = 0.005), and radial or penetrating vessels (OR = 7.54, p = 0.003) were independent diagnostic indicators included to establish the CEUS diagnostic criteria. The sensitivity and specificity of BI-RADS-US, CEUS, and BI-RADS-US combined with CEUS were 100 and 30.2%, 80.4 and 74.6%, and 94.6 and 77.8%, respectively; the corresponding areas under the receiver operating characteristic curve (AUC) were 0.819, 0.775, and 0.885, respectively.

CONCLUSIONS

CEUS has a high specificity in malignant NML diagnosis based on the diagnostic criteria including enhancement degree, enhancement area, and radial or penetrating vessels, but with lower sensitivity than BI-RADS-US. The combination of CEUS and BI-RADS-US is an effective diagnostic tool with both high sensitivity and specificity for the diagnosis of malignant NMLs.

ADVANCES IN KNOWLEDGE

In this study, we assessed the diagnostic value of CEUS for malignant NMLs and constructed a feasible diagnostic criterion. We further revealed that the combination of CEUS and BI-RADS-US has a high diagnostic value for malignant NMLs.

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.

Incremental diagnostic value of shear wave elastography combined with contrast-enhanced ultrasound in TI-RADS category 4a and 4b nodules

PURPOSE

To evaluate the diagnostic value of shear wave elastography (SWE) combined with contrast-enhanced ultrasonography (CEUS) in diagnosing thyroid imaging reporting and data system (TI-RADS) category 4a and 4b nodules.

METHODS

TI-RADS, SWE, and CEUS features of 71 thyroid nodules (23 benign, 48 malignant) confirmed by postoperative pathological results were retrospectively analyzed. The diagnostic efficiency of each single method and that of a combination of three methods were compared.

RESULTS

The sensitivity and specificity in diagnosing thyroid nodules were 70.83% and 65.22% for TI-RADS, 68.75% and 91.30% for SWE, 77.08% and 78.26% for CEUS, and 91.67% and 95.65% for TI-RADS + SWE + CEUS, respectively. The area under the curve for TI-RADS, SWE, CEUS, and TI-RADS + SWE + CEUS in diagnosing thyroid nodules were 0.680, 0.839, 0.799, and 0.937, respectively. A significant difference was observed between a combination of the three methods and any of them alone (p < 0.05).

CONCLUSION

Combining SWE and CEUS improves the differential diagnosis of TI-RADS category 4a and 4b nodules.

A Prospective Study on the Value of Ultrasound Microflow Assessment to Distinguish Malignant from Benign Solid Breast Masses: Association between Ultrasound Parameters and Histologic Microvessel Densities

OBJECTIVE

To investigate the value of ultrasound (US) microflow assessment in distinguishing malignant from benign solid breast masses as well as the association between US parameters and histologic microvessel density (MVD).

MATERIALS AND METHODS

Ninety-eight breast masses (57 benign and 41 malignant) were examined using Superb Microvascular Imaging (SMI) and contrast-enhanced US (CEUS) before biopsy. Two radiologists evaluated the quantitative and qualitative vascular parameters on SMI (vascular index, morphology, distribution, and penetration) and CEUS (time-intensity curve analysis and enhancement characteristics). US parameters were compared between benign and malignant masses and the diagnostic performance was compared between SMI and CEUS. Subgroup analysis was performed according to lesion size. The effect of vascular parameters on downgrading Breast Imaging Reporting and Data System (BI-RADS) category 4A masses was evaluated. The association between histologic MVD and US parameters was analyzed.

RESULTS

Malignant masses were associated with a higher vascular index (15.1 ± 7.3 vs. 5.9 ± 5.6), complex vessel morphology (82.9% vs. 42.1%), central vascularity (95.1% vs. 59.6%), penetrating vessels (80.5% vs. 31.6%) on SMI (all, p < 0.001), as well as higher peak intensity (37.1 ± 25.7 vs. 17.0 ± 15.8, p < 0.001), slope (10.6 ± 11.2 vs. 3.9 ± 4.2, p = 0.001), area (1035.7 ± 726.9 vs. 458.2 ± 410.2, p < 0.001), hyperenhancement (95.1% vs. 70.2%, p = 0.005), centripetal enhancement (70.7% vs. 45.6%, p = 0.023), penetrating vessels (65.9% vs. 22.8%, p < 0.001), and perfusion defects (31.7% vs. 3.5%, p < 0.001) on CEUS (p ≤ 0.023). The areas under the receiver operating characteristic curve (AUCs) of SMI and CEUS were 0.853 and 0.841, respectively (p = 0.803). In 19 masses measuring < 10 mm, central vascularity on SMI was associated with malignancy (100% vs. 38.5%, p = 0.018). Considering all benign SMI parameters on the BI-RADS assessment, unnecessary biopsies could be avoided in 12 category 4A masses with improved AUCs (0.500 vs. 0.605, p < 0.001). US vascular parameters associated with malignancy showed higher MVD (p ≤ 0.016). MVD was higher in malignant masses than in benign masses, and malignant masses negative for estrogen receptor or positive for Ki67 had higher MVD (p < 0.05).

CONCLUSION

US microflow assessment using SMI and CEUS is valuable in distinguishing malignant from benign solid breast masses, and US vascular parameters are associated with histologic MVD.

Probability analysis of axillary lymph node metastasis in breast cancer patients using particle space-time distribution model

The possibility of axillary lymph node metastasis differs in different breast cancer patients and is the strongest prognostic indicator in breast cancer. The existing studies mainly explored the relationship of axillary ultrasound imaging and axillary lymph node metastasis, without exploring whether ultrasound imaging of breast tumour can affect and perform axillary lymph node prediction. Therefore, this Letter proposes a novel particle space-time distribution model to find the correlation between contrast-enhanced ultrasonography of breast tumour and axillary lymphatic metastasis. Starting from the imaging principle of dynamic contrast-enhanced ultrasonography, the particle space-time distribution model not only comprises space-time features of contrast-enhanced ultrasonography with an encoder-decoder network, but also the flow field information of microbubble particles is integrated into the space-time features that better serves the metastasis prediction by enhancing the particle distribution information. Extensive experiments on real patients have demonstrated that dynamic contrast-enhanced ultrasonography of breast tumour can be used to predict the probability of lymphatic metastasis. This conclusion can be interpretable from the clinical and pathological perspectives.

BI-RADS 4 breast lesions: could multi-mode ultrasound be helpful for their diagnosis?

Background

The malignant probability of Breast Imaging Reporting and Data System (BI-RADS) 4 breast lesions is 3-94%, which is a very large span, and thus leads to a high rate of unnecessary biopsy. Therefore, the differential diagnosis of benign and malignant BI-RADS 4 breast lesions has become extremely important. Thus, in this paper, we investigated the diagnostic value of conventional ultrasonography (US), contrast-enhanced ultrasound (CEUS) and shear wave elastography (SWE) for BI-RADS 4 breast lesions, and tried to figure out a multi-mode ultrasonic method for them.

Methods

From March 2016 to May 2017, 118 breast lesions that were categorized as BI-RADS 4 lesions by US were studied with CEUS and SWE. All the lesions were confirmed by pathology via surgery or vacuum-assisted biopsy. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of US, CEUS and SWE were analyzed. Then the diagnostic efficacies of US, CEUS, SWE and the combination of these modalities were compared. Logistic regression analysis was performed to identify the independent risk factors. A multi-mode method to evaluate BI-RADS 4 lesions based on the logistic regression was developed.

Results

Of the 118 BI-RADS 4 lesions, 74 lesions (62.7%) were benign and 44 lesions (37.3%) were malignant. The diagnostic sensitivity and specificity for US, US + CEUS, US + SWE, US + CEUS + SWE were 88.6% and 75.7%, 86.4% and 94.6%, 88.6% and 90.5%, 97.7% and 93.2%, respectively. The area under the ROC curve (AUC) of US + SWE + CEUS was significantly higher than that of US (P<0.0001), US + CEUS (P=0.020), but there was no significant difference between the AUC of US + SWE + CEUS and the AUC of US + SWE.

Conclusions

US + CEUS + SWE and US + SWE could significantly improve the diagnostic efficiency and accuracy of US in the diagnosis of BI-RADS 4 breast lesions.

New Doppler imaging technique for assessing angiogenesis in breast tumors: correlation with immunohistochemically analyzed microvessels density

BACKGROUND

Microvessel density (MVD) is associated with grade and prognosis in breast tumors. However, conventional color Doppler flow (CDF) imaging has been limited to represent MVD of breast tumors.

PURPOSE

To evaluate whether a new Doppler imaging technique (AngioPLUS) can represent MVD of breast tumors.

MATERIAL AND METHODS

The institutional review board approved this retrospective study, and patients' informed consent was waived. CDF and AngioPLUS were available in pathologically confirmed 55 breast tumors of 53 women. For each lesion, vascular flow patterns (distribution and amount) of both Doppler images were retrospectively reviewed, and MVD was measured using immunohistochemical analysis of the biopsied tissue sections. MVD was subcategorized as low or high group with reference to the median. The associations between the Doppler features and MVD were evaluated using Fisher's exact test and Student's t test.

RESULTS

Of the 55 masses, 28 (50.9%) were benign and 27 (49.1%) were malignant. Vascular flow distribution and amount of both Doppler imaging were different between the benign and malignant lesions (CDF, P = 0.020 and P = 0.010; AngioPLUS, P = 0.002 and P = 0.005). MVD had no significant relationships with CDF features, but vascular flow distribution on AngioPLUS showed significant differences between the lesions with low and high MVD ( P = 0.020); Combined distribution was more frequent in the high MVD lesions than in the low MVD lesions (17/28, 60.7% vs. 6/27, 22.2%).

CONCLUSION

Our data confirmed the correlation between a new Doppler imaging technique, AngioPLUS, and MVD. We suggest that AngioPLUS can be used for assessing MVD in breast tumors.

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.

Can different regions of interest influence the diagnosis of benign and malignant breast lesions using quantitative parameters of contrast-enhanced sonography?

OBJECTIVES

To evaluate the diagnostic utility of quantitative parameters which generated in different regions of interests (ROIs) of benign and malignant breast lesions using contrast-enhanced sonography(CEUS).

MATERIALS AND METHODS

130 patients were evaluated with contrast harmonic imaging after the injection of a bolus dose of 4.8 ml SonoVue (Bracco Sp A, Milan, Italy). Quantitative analyses using the TIC were performed in two types of ROI (manually tracing the whole lesions and using 3-mm rectangular sampling frames to depict local lesions).Wash in slope (WIS), rise time (RT), time to peak (TTP),peak intensity (PI),strengthening intensity (SI),wash out slope(WOS) and mean transit time(MTT) were investigated in each ROI, SI includes the strengthening intensity of the lesion itself(SIs) and its strengthening intensity relative to the reference area(SIr).

RESULTS

Pathologic analysis showed 52 benign and 78 malignant lesions. There were significant differences in the quantitative parameters obtained by the two ROI types (P < 0.05). There were significant differences between benign and malignant lesions in the WIS-e(P < 0.05), TTP-e(P < 0.05), and SIr-e (P < 0.05) for the manual ROI. Significant differences were found between benign and malignant lesions in the WIS-l(P < 0.05), TTP-l(P < 0.05), PI-l(P < 0.05), SIs-l(P < 0.05), and SIr-l (P < 0.05) for the 3-mm ROI. The regression equation obtained by ROI-e was P = 1/[1 + e^{-(2.65-0.184TTP-e)}]. The regression equation obtained by ROI-l was P = 1/[1 + e^{-(2.472+0.024SIr-l-0.279TTP-l)}]. There was statistically significant difference in the diagnostic efficacy between the two ROI types (P < 0.05).

CONCLUSIONS

CEUS quantitative analysis has a certain value in the diagnosis of benign and malignant breast lesions. The ROI type which depicts local lesions can better reflect the hemodynamic characteristics of the lesions.

Association between enhancement patterns and parameters of contrast-enhanced ultrasound and microvessel distribution in breast cancer

The aim of the present study was to evaluate the association between enhancement patterns and parameters in contrast-enhanced ultrasonography (CEUS) and microvessel distribution and histological prognostic tumor characteristics of breast cancer. Between September 2011 and April 2013, 109 breast lesions were prospectively analyzed, which were classified into Breast Imaging Reporting and Data System class 4-5 by conventional ultrasound. Before core-needle biopsy, CEUS examination was performed. Different enhancement patterns (homogeneous, peripheral and regional enhancement) were evaluated. Following CEUS, biopsies were performed at the same body positions under guidance of ultrasound. Parameters (wash-in time, peak intensity, time to peak, area under the time-intensity curve, ascending slope) of CEUS at corresponding puncture sites were recorded. Microvessel density (MVD) and pathological prognostic factors, including histological grade, lymph node status, tumor-node-metastasis stage, estrogen and progesterone receptor status, Ki-67 proliferative index and human epidermal growth factor receptor 2 overexpression, were determined. Mann-Whitney U test, Spearman's rank-correlation test and independent-samples t-tests were used for evaluation. Core-needle biopsy or surgical resection specimens of 99 malignant breast lesions were included in the present study. Of the 99 malignant lesions, 44 lesions exhibited homogeneous enhancement, 43 exhibited peripheral enhancement and 12 exhibited regional enhancement. Lesions with peripheral enhancement exhibited a higher peripheral/central ratio of MVD compared with lesions with homogeneous enhancement (P<0.001). Peak intensity and ascending slope ratios of tumor periphery/center were correlated with the corresponding MVD ratios (P=0.017 and P=0.016, respectively). MVD ratio was positively correlated with histological grade (P=0.003). In conclusion, the enhancement patterns and parameters of CEUS may not only reflect the microvessel distribution but also indirectly indicate the histological grade of breast cancer.

Contrast-Enhanced Ultrasound Differentiation Between Low- and High- Grade Bladder Urothelial Carcinoma and Correlation With Tumor Microvessel Density

OBJECTIVES

Time-intensity curves (TICs) of contrast-enhanced ultrasound (CEUS) were analyzed retrospectively to differentiate between low-grade and high-grade bladder urothelial carcinoma, and to investigate correlation with tumor microvessel density (MVD).

METHODS

The data of 105 patients with pathologically confirmed bladder urothelial carcinoma (55 low-grade and 50 high-grade) were reviewed. Lesions were examined before surgery using conventional ultrasound and CEUS with TIC analysis. The TIC parameters time from peak to one-half the signal intensity (TPH) and the corresponding descending slope (DS) of the low-grade and high-grade groups were compared, and receiver operating characteristic curves constructed. The MVDs of the resectioned tissue specimens were quantified via immunohistochemistry for CD34.

RESULTS

Based on conventional ultrasound, the low-grade and high-grade groups were similar in tumor shape, number, topography, internal echo, height, width, and vascularity. The TPH of the high-grade group was significantly longer than that of the low-grade group, and the DS was lower. The cutoff points of TPH and DS for differentiating low-grade and high-grade bladder urothelial carcinoma were 48.06 seconds and 0.15 dB/seconds, respectively (area under the receiver operating characteristic curve = 0.79 for both). The mean MVDs per high-power field of the low-grade and high-grade groups were 41.39 16.65 and 51.03 20.16, respectively (P = .009). The TPH correlated linearly with MVD (P < .01), as did the DS (P < .01).

CONCLUSIONS

Contrast-enhanced ultrasound can be used to differentiate low from high-grade bladder urothelial carcinoma. The TIC parameters of CEUS reflect the MVD of bladder urothelial tumors and may be helpful for evaluating tumor angiogenesis, with implications for clinical diagnosis, treatment, and prognosis.

Regional Contrast-Enhanced Ultrasonography (CEUS) Characteristics of Breast Cancer and Correlation with Microvessel Density (MVD)

Background

The aim of this study was to investigate the perfusion characteristics of different breast lesion regions in contrast-enhanced ultrasonography (CEUS).

Material/Methods

A total of 161 malignant and benign breast lesion cases were subjected to CEUS. Perfusion parameters were analyzed and compared between the central and peripheral lesion regions, and surrounding tissue. Mass section was marked with methylene blue. Samples were subjected to immunohistochemistry, and microvessel density (MVD) was calculated.

Results

There were significant differences in perfusion performance between the central and peripheral lesion regions, and surrounding tissue. In the malignant tumors, the fast-in and fast-out pattern was the most common type in the peripheral region (57.98%), while the slow-in and slow-out patterns were the major types in the central region and surrounding tissue (49.58% and 57.98%, respectively). Compared with the surrounding tissue, the peripheral region in the cancers exhibited hyperechoic enhancement and fast-in and slow-out pattern, with large area under the curve (AUC), while the central region showed isoechoic enhancement and equally-in and slow-out pattern, with large AUC. In the benign lesions, the peripheral region exhibited hyperechoic enhancement and fast-in and fast-out pattern, with small AUC, while the central region showed isoechoic enhancement and equally-in and -out pattern, with the same AUC value. Moreover, the perfusion parameters in the central and peripheral regions were significantly associated with MVD.

Conclusions

It is more objective to evaluate the perfusion performance of breast lesions with the reference of surrounding tissue. Compared with the central region, the peripheral region could better reflect the perfusion characteristics of malignant lesions.

Modulation of mammary tumor vascularization by mast cells: Ultrasonographic and histopathological approaches

AIMS

The inhibition of mast cells' degranulation may be an approach to prevent the formation of new vessels during the mammary carcinogenesis.

MATERIALS AND METHODS

Female Sprague-Dawley rats were randomly divided into five experimental groups. Mammary tumors were induced by intraperitoneal injection of N-methyl-N-nitrosourea (MNU). Animals from group II were treated with ketotifen for 18weeks immediately after the MNU administration, while animals from group III only received the ketotifen after the development of the first mammary tumor. Mammary tumors vascularization was assessed by ultrasonography (Doppler, B Flow and contrast-enhanced ultrasound) and immunohistochemistry (vascular endothelial growth factor-A).

KEY FINDINGS AND SIGNIFICANCE

Similar to what occurs in women with breast cancer, the majority of MNU-induced mammary tumors exhibited a centripetal enhancement order of the contrast agent, clear margin and heterogeneous enhancement. Ultrasonographic and immunohistochemical data suggest that the inhibition of mast cells' degranulation did not change the mammary tumors vascularization.

Compound speckle model detects anti-angiogenic tumor response in preclinical nonlinear contrast-enhanced ultrasonography

PURPOSE

This paper proposes a method for analyzing the first-order speckle statistics of nonlinear contrast-enhanced ultrasound images from tumors.

METHODS

Contrast signal intensity is modeled as a compound distribution of exponential probability density functions with a gamma weighting function. The gamma probability weighting function serves as an approximation for log-normally distributed flow velocities in a vascular network. The model was applied to sub-harmonic bolus-injection images acquired from a mouse breast cancer xenograft model treated with murine version bevacizumab.

RESULTS

The area under curve produced using the compound statistical model could more accurately discriminate anti-VEGF-treated tumors from untreated tumors than conventional contrast-enhanced ultrasound image processing. This result was validated with gold standard histological measures of microvascular density. Fractal vessel geometry was estimated using the gamma weighting function and tested against micro-CT perfusion casting. Treated tumors had a significantly lower vascular fractal dimension than control tumors. Vascular complexity estimated using the ultrasound compound statistical model performed similarly to micro-CT fractal dimension for discriminating treated from control tumors.

CONCLUSION

The proposed technique can quantify tumor perfusion and provide an index of vascular complexity, making it a potentially useful addition for clinical detection of vascular normalization in anti-angiogenic trials.

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.

Predicting lymph node metastasis in patients with papillary thyroid carcinoma by vascular index on power Doppler ultrasound

BACKGROUND

For patients with papillary thyroid carcinoma (PTC), lymph node metastasis is associated with an increased recurrence rate. The purpose of this study was to investigate whether the vascular endothelial growth factor (VEGF), microvessel density (MVD), and vascular index (VI) can predict lymph node metastasis in patients with PTC.

METHODS

From January 2011 to October 2011, 202 patients with PTCs underwent preoperative staging ultrasound evaluation. To evaluate vascularity, we measured the VI, VEGF expression, and MVD.

RESULTS

The VI was significantly correlated with MVD (p = .009). On multivariate analysis, young age showed a significant correlation with lymph node metastasis (p < .001; p < .001; p < .001). However, the other clinicopathologic features, VEGF, MVD, and VI failed to show any significant correlations with lymph node metastasis.

CONCLUSION

Although the VI showed significant correlation with MVD, it was not significantly correlated to lymph node metastasis. © 2016 Wiley Periodicals, Inc. Head Neck 39: 334-340, 2017.

Three-dimensional Contrast-enhanced Ultrasound in Response Assessment for Breast Cancer: A Comparison with Dynamic Contrast-enhanced Magnetic Resonance Imaging and Pathology

To compare the capabilities of three-dimensional contrast enhanced ultrasound (3D-CEUS) and dynamic contrast-enhanced magnetic resonance (DCE-MRI) in predicting the response to neoadjuvant chemotherapy (NAC) among breast cancer patients, 48 patients with unilateral breast cancer were recruited for 3D-CEUS and DCE-MRI examinations both before and after NAC; pathology was used to validate the results. This study was approved by the institutional review board, and written informed consent was obtained from each patient. Imaging feature changes and pathological vascularity response, including microvessel density (MVD) and vascular endothelial growth factor (VEGF), were calculated. Pathological complete response (pCR) and major histological response (MHR) were used as references. The 3D-CEUS score, DCE-MRI score, MVD and VEGF significantly decreased (P < 0.0001) after NAC. The correlations between Δ3D-CEUS and ΔDCE-MRI with pCR (r = 0.649, P < 0.0001; r = 0.639, P < 0.0001) and MHR (r = 0.863, P < 0.0001; r = 0.836, P < 0.0001) were significant. All scores showed significant differences between the pCR and non-pCR groups with folder changes of 0.1, 0.1, 2.4, and 2.3, respectively (P = 0.0001, <0.0001, <0.0001 and <0.0001). In conclusion, 3D-CEUS is effective in assessing the response of breast cancer patients undergoing NAC.

Correlation of contrast-enhanced ultrasonographic features with microvessel density in papillary thyroid carcinomas

BACKGROUND

The purpose of this study was to investigate the correlation of contrast-enhanced ultrasonographic (CEUS) features with microvessel density (MVD) in papillary thyroid carcinomas (PTCs).

MATERIALS AND METHODS

Contrast-enhanced ultrasonography (CEUS) was performed in 62 patients (17 men and 45 women) with PTC. Tomtec software was applied to analyze the time intensity curve of CEUS. Immunohistochemistry was performed to evaluate the level of MVD in papillary thyroid carcinoma. Then the relationship between quantitative feature and the level of MVD was analyzed using SPSS 16.0 software.

RESULTS

The mean peak intensity of PTC tissues was lower than that of peripheral thyroid parenchyma (61.9 ± 11.8% vs 100%, p < 0.05). The MVDs of CD34 and CD31 antibodies staining were 38.0 ± 6.1 and 37.9 ± 5.1 respectively in 62 PTC samples. A significantly positive correlation was observed between peak intensity and MVD in PTC tissues (PCD34 < 0.01, rCD34 = 0.838, PCD31 < 0.01, rCD31 = 0.837).

CONCLUSIONS

The peak intensity in CEUS could reflect the MVD in PTC tissues. Therefore, quantification of CEUS seems to be helpful for assessment of MVD in PTC tissues.

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.

Comparison of photoacoustically derived hemoglobin and oxygenation measurements with contrast-enhanced ultrasound estimated vascularity and immunohistochemical staining in a breast cancer model

In this preliminary study, we compared two noninvasive techniques for imaging intratumoral physiological conditions to immunohistochemical staining in a murine breast cancer model. MDA-MB-231 tumors were implanted in the mammary pad of 11 nude rats. Ultrasound and photoacoustic (PA) scanning were performed using a Vevo 2100 scanner (Visualsonics, Toronto, Canada). Contrast-enhanced ultrasound (CEUS) was used to create maximum intensity projections as a measure of tumor vascularity. PAs were used to determine total hemoglobin signal (HbT), oxygenation levels in detected blood (SO2 Avg), and oxygenation levels over the entire tumor area (SO2 Tot). Tumors were then stained for vascular endothelial growth factor (VEGF), cyclooxygenase-2 (Cox-2), and the platelet endothelial cell adhesion molecule CD31. Correlations between findings were analyzed using Pearson's coefficient. Significant correlation was observed between CEUS-derived vascularity measurements and both PA indicators of blood volume (r = 0.49 for HbT, r = 0.50 for SO2 Tot). Cox-2 showed significant negative correlation with SO2 Avg (r = -0.49, p = 0.020) and SO2 Tot (r = -0.43, p = 0.047), while CD31 showed significant negative correlation with CEUS-derived vascularity (r = -0.47, p = 0.036). However, no significant correlation was observed between VEGF expression and any imaging modality (p > 0.08). Photoacoustically derived HbT and SO2 Tot may be a good indicator of tumor fractional vascularity. While CEUS correlates with CD31 expression, photoacoustically derived SO2 Avg appears to be a better predictor of Cox-2 expression.

Time-intensity curve parameters in rectal cancer measured using endorectal ultrasonography with sterile coupling gels filling the rectum: correlations with tumor angiogenesis and clinicopathological features

The primary aim of this study was to investigate the relationship between contrast-enhanced ultrasonography (CEUS) imaging parameters and clinicopathological features of rectal carcinoma and assess their potential as new radiological prognostic predictors. A total of 66 rectal carcinoma patients were analyzed with the time-intensity curve of CEUS. The parameter arrival time (AT), time to peak enhancement (TTP), wash-in time (WIT), enhanced intensity (EI), and ascending slope (AS) were measured. Microvessel density (MVD) was evaluated by immunohistochemical staining of surgical specimens. All findings were analysed prospectively and correlated with tumor staging, histological grading, and MVD. The mean values of AT, TTP, WIT, EI, and AS value of the rectal carcinoma were 10.84 ± 3.28 s, 20.61 ± 5.52 s, 9.78 ± 2.83 s, 28.68 ± 4.67 dB, and 3.20 ± 1.10, respectively. A positive linear correlation was found between the EI and MVD in rectal carcinoma (r = 0.295, P = 0.016), and there was a significant difference for EI among histological grading (r = -0.264, P = 0.007). EI decreased as T stage increased with a trend of association noted (P = 0.096). EI of contrast enhanced endorectal ultrasonography provides noninvasive biomarker of tumor angiogenesis in rectal cancer. CEUS data have the potential to predict patient prognosis.

Diagnostic efficacy of contrast-enhanced sonography by combined qualitative and quantitative analysis in breast lesions: a comparative study with magnetic resonance imaging

OBJECTIVES

The purpose of this study was to evaluate the diagnostic efficacy of contrast-enhanced sonography for differentiation of breast lesions by combined qualitative and quantitative analyses in comparison to magnetic resonance imaging (MRI).

METHODS

Fifty-six patients with American College of Radiology Breast Imaging Reporting and Data System category 3 to 5 breast lesions on conventional sonography were evaluated by contrast-enhanced sonography and MRI. A comparative analysis of diagnostic results between contrast-enhanced sonography and MRI was conducted in light of the pathologic findings.

RESULTS

Pathologic analysis showed 26 benign and 30 malignant lesions. The predominant enhancement patterns of the benign lesions on contrast-enhanced sonography were homogeneous, centrifugal, and isoenhancement or hypoenhancement, whereas the patterns of the malignant lesions were mainly heterogeneous, centripetal, and hyperenhancement. The detection rates for perfusion defects and peripheral radial vessels in the malignant group were much higher than those in the benign group (P < .05). As to quantitative analysis, statistically significant differences were found in peak and time-to-peak values between the groups (P < .05). With pathologic findings as the reference standard, the sensitivity, specificity, and accuracy of contrast-enhanced sonography and MRI were 90.0%, 92.3%, 91.1% and 96.7%, 88.5%, and 92.9%, respectively. The two methods had a concordant rate of 87.5% (49 of 56), and the concordance test gave a value of κ = 0.75, indicating that there was high concordance in breast lesion assessment between the two diagnostic modalities.

CONCLUSIONS

Contrast-enhanced sonography provided typical enhancement patterns and valuable quantitative parameters, which showed good agreement with MRI in diagnostic efficacy and may potentially improve characterization of breast lesions.

Incorporating prognostic imaging biomarkers into clinical practice

A prognostic imaging biomarker can be defined as an imaging characteristic that is objectively measurable and provides information on the likely outcome of the cancer disease in an untreated individual and should be distinguished from predictive imaging biomarkers and imaging markers of response. A range of tumour characteristics of potential prognostic value can be measured using a variety imaging modalities. However, none has currently been adopted into routine clinical practice. This article considers key examples of emerging prognostic imaging biomarkers and proposes an evaluation framework that aims to demonstrate clinical efficacy and so support their introduction into the clinical arena. With appropriate validation within an established evaluation framework, prognostic imaging biomarkers have the potential to contribute to individualized cancer care, in some cases reducing the financial burden of expensive cancer treatments by facilitating their more rational use.

Correlation of ultrasound contrast agent derived blood flow parameters with immunohistochemical angiogenesis markers in murine xenograft tumor models

PURPOSE

In this study we used temporal analysis of ultrasound contrast agent (UCA) estimate blood flow dynamics and demonstrate their improved correlation to angiogenesis markers relative to previously reported, non-temporal fractional vascularity estimates.

MATERIALS AND METHODS

Breast tumor (NMU) or glioma (C6) cells were implanted in either the abdomen or thigh of 144 rats. After 6, 8 or 10 days, rats received a bolus UCA injection of Optison (GE Healthcare, Princeton, NJ; 0.4 ml/kg) during power Doppler imaging (PDI), harmonic imaging (HI), and microflow imaging (MFI) using an Aplio ultrasound scanner with 7.5 MHz linear array (Toshiba America Medical Systems, Tustin, CA). Time-intensity curves of contrast wash-in were constructed on a pixel-by-pixel basis and averaged to calculate maximum intensity, time to peak, perfusion, and time integrated intensity (TII). Tumors were then stained for four immunohistochemical markers (bFGF, CD31, COX-2, and VEGF). Correlations between temporal parameters and the angiogenesis markers were investigated for each imaging mode. Effects of tumor model and implant location on these correlations were also investigated.

RESULTS

Significant correlation over the entire dataset was only observed between TII and VEGF for all three imaging modes (R=-0.35, -0.54, -0.32 for PDI, HI and MFI, respectively; p<0.0001). Tumor type and location affected these correlations, with the strongest correlation of TII to VEGF found to be with implanted C6 cells (R=-0.43, -0.54, -0.52 for PDI, HI and MFI, respectively; p<0.0002).

CONCLUSIONS

While UCA-derived temporal blood flow parameters were found to correlate strongly with VEGF expression, these correlations were also found to be influenced by both tumor type and implant location.

Perfusion heterogeneity in breast tumors for assessment of angiogenesis

OBJECTIVES

The purpose of this study was to investigate the perfusion heterogeneity of malignant and benign breast tumors and assay their vascular architecture changes and molecular expression, thereby evaluating the relevance between imaging and histologic characteristics of angiogenesis.

METHODS

Real-time grayscale contrast-enhanced sonography was performed in 310 women with 317 breast tumors. The enhancement patterns and perfusion parameters for malignant and benign tumors were analyzed by contrast-enhanced sonography with microvascular imaging and quantitative time-intensity curve analysis. Structural characteristics were observed by light and electron microscopy. The microvessel density, vascular endothelial growth factor (VEGF) expression, and human kinase insert domain-containing receptor (KDR) expression for all tumors were assessed by immunohistochemical staining of CD31, KDR, and VEGF.

RESULTS

Surgical pathologic analysis showed 163 malignant and 154 benign tumors. Significant morphologic differences, including perfusion defects, vessel distortion, vessel dilatation, and heterogeneous enhancement, were observed between the malignant and benign groups (P < .05). The mean perfusion parameters (peak intensity, ascending slope, area under the curve, and wash-out time) were greater in the malignant tumors (P < .05). There were significant differences in the peak intensity, ascending slope, area under the curve, and wash-out time between peripheral and central regions of the malignant tumors (P < .05) but none in the benign tumors. Vessels had various morphologic and distributional characteristics in the peripheral and central regions of the malignant tumors. The microvessel density and VEGF and KDR expression were significantly higher in the malignant group (P < .05), especially in the peripheral regions.

CONCLUSIONS

Perfusion heterogeneity was closely associated with the tumor microvascular architecture and molecular expression. Perfusion features, especially regional morphologic and hemodynamic features, can provide valuable information for differentiating malignant from benign breast tumors.

2D ultrasonography and contrast enhanced ultrasound for the evaluation of cavitating mesenteric lymph node syndrome in a patient with refractory celiac disease and enteropathy T cell lymphoma

Background

The cavitating mesenteric lymph node syndrome (CMLNS) is a rare manifestation of celiac disease, with an estimated mortality rate of 50%. Specific infections and malignant lymphoma may complicate its clinical course and contribute to its poor prognosis. Diagnosing the underlying cause of CMLNS can be challenging. This is the first report on contrast enhanced ultrasound (CEUS) findings in enteropathy associated T-cell lymphoma (EATL) complicating CMLNS in a gluten-free compliant patient with persistent symptoms and poor outcome.

Case presentation

We present the case of a 51-year old Caucasian male patient, diagnosed with celiac disease and CMLNS. Despite his compliance to the gluten-free diet the symptoms persisted and we eventually considered the possible development of malignancy. No mucosal changes suggestive of lymphoma were identified with capsule endoscopy. Low attenuation mesenteric lymphadenopathy, without enlarged small bowel segments were seen on computed tomography. CEUS revealed arterial rim enhancement around the necrotic mesenteric lymph nodes, without venous wash-out. No malignant cells were identified on laparoscopic mesenteric lymph nodes biopsies. The patient died due to fulminant liver failure 14 months later; the histopathological examination revealed CD3/CD30-positive atypical T-cell lymphocytes in the liver, mesenteric tissue, spleen, gastric wall, kidney, lung and bone marrow samples; no malignant cells were present in the small bowel samples.

Conclusions

CEUS findings in EATL complicating CMLNS include arterial rim enhancement of the mesenteric tissue around the cavitating lymph nodes, without venous wash-out. This vascular pattern is not suggestive for neoangiogenesis, as arteriovenous shunts from malignant tissues are responsible for rapid venous wash-out of the contrast agent. CEUS failed to provide a diagnosis in this case.

A comparative evaluation of ultrasound molecular imaging, perfusion imaging, and volume measurements in evaluating response to therapy in patient-derived xenografts

Most pre-clinical therapy studies use the change in tumor volume as a measure for disease response. However, tumor size measurements alone may not reflect early changes in tumor physiology that occur as a response to treatment. Ultrasonic molecular imaging (USMI) and Dynamic Contrast Enhanced-Perfusion Imaging (DCE-PI) with ultrasound are two attractive alternatives to tumor volume measurements. Since these techniques can provide information prior to the appearance of gross phenotypic changes, it has been proposed that USMI and DCE-PI could be used to characterize response to treatment earlier than traditional methods. This study evaluated the ability of tumor volume measurements, DCE-PI, and USMI to characterize response to therapy in two different types of patient-derived xenografts (known responders and known non-responders). For both responders and non-responders, 7 animals received a dose of 30 mg/kg of MLN8237, an investigational aurora-A kinase inhibitor, for 14 days or a vehicle control. Volumetric USMI (target integrin:α av β3) and DCE-PI were performed on day 0, day 2, day 7, and day 14 in the same animals. For USMI, day 2 was the earliest point at which there was a statistical difference between the untreated and treated populations in the responder cohort (Untreated: 1.20 ± 0.53 vs. Treated: 0.49 ± 0.40; p < 0.05). In contrast, statistically significant differences between the untreated and treated populations as detected using DCE-PI were not observed until day 14 (Untreated: 0.94 ± 0.23 vs. Treated: 1.31 ± 0.22; p < 0.05). Volume measurements alone suggested no statistical differences between treated and untreated populations at any readpoint. Monitoring volumetric changes is the "gold standard" for evaluating treatment in pre-clinical studies, however, our data suggests that volumetric USMI and DCE-PI may be used to earlier classify and robustly characterize tumor response.

Computational modelling of anti-angiogenic therapies based on multiparametric molecular imaging data

Computational tumour models have emerged as powerful tools for the optimization of cancer therapies; ideally, these models should incorporate patient-specific imaging data indicative of therapeutic response. The purpose of this study was to develop a tumour modelling framework in order to simulate the therapeutic effects of anti-angiogenic agents based upon clinical molecular imaging data. The model was applied to positron emission tomography (PET) data of cellular proliferation and hypoxia from a phase I clinical trial of bevacizumab, an antibody that neutralizes the vascular endothelial growth factor (VEGF). When using pre-therapy PET data in combination with literature-based dose response parameters, simulated follow-up hypoxia data yielded good qualitative agreement with imaged hypoxia levels. Improving the quantitative agreement with follow-up hypoxia and proliferation PET data required tuning of the maximum vascular growth fraction (VGF(max)) and the tumour cell cycle time to patient-specific values. VGF(max) was found to be the most sensitive model parameter (CV = 22%). Assuming availability of patient-specific, intratumoural VEGF levels, we show how bevacizumab dose levels can potentially be 'tailored' to improve levels of tumour hypoxia while maintaining proliferative response, both of which are critically important in the context of combination therapy. Our results suggest that, upon further validation, the application of image-driven computational models may afford opportunities to optimize dosing regimens and combination therapies in a patient-specific manner.

Systemic delivery of a breast cancer-detecting adenovirus using targeted microbubbles

One of the major limitations of cancer gene therapy using recombinant human adenovirus (Ad) is rapid Ad inactivation from systemic delivery. To eliminate this, biotin-coated ultrasound contrast agents, or microbubbles (MBs), were streptavidin-coupled with biotinylated antibodies to three distinct tumor vasculature-associated receptors (α(V)β(3) integrin, P-selectin and vascular endothelial growth factor receptor-2) for systemic targeting of a previously generated vector Ad5/3-Id1-SEAP-Id1-mCherry. This cancer-specific, dual-reporter vector was loaded in the targeted MBs and confirmed by confocal microscopy. MB loading capacity was estimated by functional assays as 4.72 ± 0.2 plaque forming unit (PFU) per MB. Non-loaded (free) Ad particles were effectively inactivated by treatment with human complement. The Ad-loaded, targeted-MBs were injected systemically in mice bearing MDA-MB-231 tumors (Grp 1) and compared with two control groups: Ad-loaded, non-targeted MBs (Grp 2) and free Ad (Grp 3) administered under the same conditions. Two days after administration the blood levels of secreted embryonic alkaline phosphatase (SEAP) reporter in Grp 1 mice (16.1 ng ml(-1) ± 2.5) were significantly higher (P<0.05) than those in Grp 2 (9.75 ng ml(-1) ± 1.5) or Grp 3 (4.26 ng ml(-1) ± 2.5) animals. The targeted Ad delivery was also confirmed by fluorescence imaging. Thus, Ad delivery by targeted MBs holds potential as a safe and effective system for systemic Ad delivery for the purpose of cancer screening.

Gray-scale contrast-enhanced ultrasonography for quantitative evaluation of the blood perfusion of the sciatic nerves with crush injury

RATIONALE AND OBJECTIVES

Blood perfusion of peripheral nerves plays an important role in regeneration after nerve injury. Functional recovery after a peripheral nerve injury depends not only on the survival of the affected neurons but also on the recovered blood perfusion. Previous studies have shown that it is possible to quantitatively assess blood perfusion of tissue using contrast-enhanced ultrasound (CEUS). The aim of this study was to evaluate the usefulness of CEUS for the quantitative evaluation of blood perfusion of the sciatic nerves with crush injury.

MATERIALS AND METHODS

Crush injuries were created in the left sciatic nerve of 30 New Zealand white rabbits. CEUS of the bilateral sciatic nerves was performed in six experimental rabbits at 3 days, 1 week, 2 weeks, 4 weeks, and 8 weeks after injury. Pulse-inversion harmonic imaging was used for real-time CEUS. The other six rabbits were used as a control group. Serial laser Doppler measurements of blood flow and quantitative histologic evaluation were performed parallel to CEUS on all animals.

RESULTS

Quantitative analysis of CEUS showed that the perfusion index of the crushed sciatic nerves was increased at 3 days after injury, with a peak at 1 week after injury (P = .000). The area under the curve for the crushed sites was increased at 3 days after injury, with a peak at 2 weeks after injury (P = .000). The mean transit time and maximum intensity of the crushed site of the left sciatic nerves were not significantly changed during the 2 months after injury (P = .335 and P = .157 respectively). The perfusion indices measured by CEUS correlated well with those measured by laser Doppler (r = 0.791, P = .000). Marked Wallerian degeneration was found at the crushed site of sciatic nerves at 3 days after injury. The percentage of degenerated myelinated axons was increased during the first 2 weeks after injury and then decreased during the following period. Regenerated axons with small diameter and thin myelin sheaths were found at 2 weeks after injury and during the following period.

CONCLUSIONS

CEUS may provide a new imaging method to quantitatively analyze blood perfusion of injured peripheral nerves.

Contrast-enhanced ultrasonography for the detection and characterization of prostate cancer: correlation with microvessel density and Gleason score

AIM

To determine whether there is a correlation between the peak intensity of the lesion at contrast-enhanced ultrasonography and the microvessel density (MVD) and Gleason score in biopsy specimens of prostate cancer.

MATERIALS AND METHODS

Contrast-enhanced ultrasonography using cadence-contrast pulse sequence (CPS) technology was performed in 147 patients with suspected prostate cancer before biopsy. An auto-tracking contrast quantification (ACQ) software was used to analyse the peak intensity (PI) of the lesion. The Gleason score and MVD immunoreactivity were determined in the prostate biopsy specimens. Ultrasound findings were correlated with biopsy findings.

RESULTS

Prostate cancer was detected in 73 of 147 patients. The PI values of prostate cancer patients were significantly higher than those of non-malignant patients [9.81 (4.23) versus 5.69 (3.19) dB; p<0.01]. The mean (SD) PIs of prostate cancer lesions with a Gleason score of 6-9 were 7.08 (3.80), 8.65 (4.08), 9.76 (3.75), and 9.85 (4.13) dB, respectively. The PI value increased significantly with a higher Gleason score (p<0.01). The mean (SD) MVDs observed in prostate cancer lesions with a Gleason score of 6-9 were 52.50 (10.54), 56.85 (10.31), 59.91 (9.29), and 66.04 (11.82), respectively. There was a positive correlation between PI and MVD in prostate cancer, with a correlation coefficient of 0.617. No correlation was found between PI value and age, prostate specific antigen (PSA) or prostate specific antigen density (PSAD) level (p>0.05).

CONCLUSION

The PI obtained by CPS harmonic ultrasonography appears to be of value as an indicator of MVD and increases with a higher Gleason score. CPS harmonic ultrasonography could be promising as a useful imaging technique in the detection and characterization of prostate cancer.

Contrast-enhanced ultrasonographic findings of different histopathologic types of breast cancer

BACKGROUND

The new application of contrast-enhanced ultrasonography (CEUS) in the diagnosis of breast masses has evolved quickly only in recent years. Nevertheless, mixed results owing to the overlap in characteristics of benign and malignant lesions are simultaneously discovered by most studies, partially attributed to different histopathologic characteristics of breast cancer.

PURPOSE

To explore the characteristics of different histopathologic types of breast cancer at real-time gray-scale CEUS and evaluate its diagnostic value.

MATERIAL AND METHODS

One hundred and one histopathologically confirmed malignant lesions were included. We retrospectively reviewed the contrast-enhanced ultrasonographic findings including morphologic features, quantitative parameters, and correlated them with histopathology. True-positive rate was calculated to assess the diagnostic performance of CEUS.

RESULTS

The 101 malignancies displayed irregular shape (72 [71%]), poorly-defined margin (73 [72%]), penetrating or tortuous surrounding vessels (79 [78%]), heterogeneous enhancement (84 [83%]), including focal perfusion defects (24 [24%]). For each histopathologic type, 87% (58/67) of invasive ductal carcinoma (IDC) showed heterogeneous enhancement. Of all the 24 perfusion defects, IDC account for 88% (21/24). Low average peak intensity (PI) of 4.9 was detected in this type. Ductal carcinoma in situ (DCIS) excellently showed the features of irregular shape (82% [14/17]), poorly-defined margin (82% [14/17]), heterogeneous enhancement (94% [16/17]). While 83% (5/6) of medullary carcinoma exhibited regular shape, well-defined margin, homogenous enhancement, and high average PI value of 9.6. Invasive lobular carcinoma showed similar enhancement pattern to that of IDC. Intraductal papillary carcinoma displayed high average PI value of 8.1. The overall true-positive rate for conventional US and CEUS was 88%, 86%, respectively. DCIS, medullary carcinoma, and intraductal papillary carcinoma achieved an improved true-positive rate (94%, 100% and 100%, respectively).

CONCLUSION

The imaging characteristics of CEUS are variable in different histopathologic types of breast cancer. CEUS does not appear to be superior to conventional ultrasound as a diagnostic tool overall, however, it is a useful adjunct to conventional ultrasound in diagnosing some special types of breast cancer.

Assessing algorithms for defining vascular architecture in subharmonic images of breast lesions

The ability to accurately and non-invasively characterize breast lesions and their vasculature would greatly limit the number of unneeded biopsies performed annually. Subharmonic ultrasound imaging (SHI) allows exclusive imaging of vasculature in real time, while completely suppressing tissue signals. Previously, cumulative maximum intensity (CMI) projections of SHI data were shown to be useful for characterization, but lacked means of quantification. In this study we investigate three potential thinning algorithms for defining breast lesion architecture. Sequential thinning, parallel thinning, and distance transformation algorithms were compared using 40 in vitro test images. Sequential thinning was selected due to superior connectivity, minimal rotational variance, and sufficient data reduction. This algorithm was then applied to 16 CMI SHI images of breast lesions, out of which 13 were successfully skeletonized. Average bifurcations were 9.8 ± 8.18 and 6.9 ± 6.50 in malignant and benign lesions, respectively (p > 0.60). Average vessel-chain length was 88.9 ± 79.10 pixels versus 63.2 ± 45.65 pixels in malignant versus benign lesions (p > 0.40). While the sequential thinning algorithm was promising for quantifying breast vasculature, its ability to significantly differentiate between malignant and benign lesions in this study was limited by a high degree of variability and limited sample size.

Contrast-enhanced ultrasound for molecular imaging of angiogenesis

INTRODUCTION

Molecular imaging of angiogenesis using contrast-enhanced ultrasound allows for functional, real-time, inexpensive imaging of angiogenesis. The addition of stabilized microbubbles as contrast agents greatly improves ultrasound signal to noise ratio/signal strength/image quality (up to 25 dB) and allows for imaging of angiogenic vasculature.

METHODS

In this article recent advances in the usage of contrast-enhanced ultrasound for molecular imaging of angiogenesis are reviewed.

RESULTS

The usage of commercially available agents and correlations between their imaging parameters and molecular markers of angiogenesis are reviewed. Recent developments in ultrasound contrast agents targeted to angiogenic markers for both diagnosis and monitoring are discussed. Finally, a brief overview of the emerging field of chemotherapeutic-loaded agents, which can be used with ultrasound-triggered drug delivery, is provided.

Quantitative evaluation of the peripheral nerve blood perfusion with high frequency contrast-enhanced ultrasound

RATIONALE AND OBJECTIVES

The blood perfusion of peripheral nerves plays an important role in regeneration after nerve injury. Previous studies have shown that it is possible to quantitatively assess the blood perfusion of the tissue using contrast-enhanced ultrasound (CEUS). The aim of this study was to evaluate the feasibility of CEUS for quantitative assessment of the blood perfusion of the sciatic nerve in normal New Zealand white rabbits and to compare these parameters to those of surrounding skeletal muscle and the main artery in the thigh.

MATERIALS AND METHODS

CEUS of the bilateral sciatic nerves was performed in 12 normal New Zealand white rabbits after a bolus injection of SonoVue (0.13 mL/kg). Pulse-inversion harmonic imaging was used for real-time CEUS. The blood perfusion of the left sciatic nerve was compared to that of its surrounding muscle, the arterial branch in the thigh, and the contralateral side.

RESULTS

The supplying arteries in the sciatic nerve could be demonstrated during the early phase of CEUS, followed by the homogeneous enhancement of the whole nerve. The area under the curve and the perfusion index of the sciatic nerve were higher than those of the surrounding muscle and lower than those of the arterial branch in the thigh (both P values = .000). The maximum intensity of the sciatic nerve was similar to that of skeletal muscle and lower than that of the arterial branch. The time to peak was not significantly different among the sciatic nerve, skeletal muscle, and arterial branch (P = .551). There were no differences in area under the curve, mean transit time, perfusion index, maximum intensity, and time to peak between the left and right sciatic nerves (P > .05).

CONCLUSIONS

CEUS may be a feasible method for the quantitative assessment of blood perfusion of the peripheral nerves.

Detecting metastasis of lymph nodes and predicting aggressiveness in patients with breast carcinomas

OBJECTIVE

The purpose of this study was to evaluate the contrast-enhanced ultrasonographic (CEUS) characteristics of metastatic lymph nodes (LNs) and to determine the correlation of CEUS parameters with the tumor aggressiveness in patients with breast cancer.

METHODS

Real-time gray scale CEUS of axillary LNs was preoperatively performed in 51 consecutive patients with breast carcinoma who were scheduled for axillary lymph node dissection. The CEUS characteristics assessed by a direct visualization method and quantification software were compared with pathologic findings. Expression of human epidermal growth factor receptor 2 (HER-2/neu) in the primary tumor was detected by immunohistochemical analysis. Correlation analysis of CEUS parameters with HER-2/neu expression and the LN stage was performed.

RESULTS

Of the LNs examined, 27 were metastatic, and 25 were diagnosed as reactive hyperplasia. Lymph nodes with metastasis were characterized by centripetal progress (66.7%) and a heterogeneous pattern (55.6%) or no or scarce perfusion (25.9%). However, LNs with nonmetastases were characterized by with centrifugal enhancement (56.0%) and a homogeneous pattern (80.0%). The difference between the hyperintense and hypointense regions was higher in metastatic LNs than nonmetastatic ones (P < .001). No significant differences were found in the arrival time, time to peak intensity, and peak intensity between the two groups. A histopathologic diagnosis could be predicted with sensitivity, specificity, and accuracy of 92.6%, 76.0%, and 84.6% respectively, by a standardized difference between maximum and minimum signal intensity (SI(max)-SI(min)) value of 28. Human epidermal growth factor receptor 2 expression and the LN histopathologic stage were significantly associated with the SI(max)-SI(min). In metastatic LNs, the relationship between the diagnostic sensitivity of CEUS and the transverse diameter of LNs remained statistically significant (P < .05).

CONCLUSIONS

Noninvasive CEUS can play a role in discriminating metastatic from nonmetastatic LNs and predicting the aggressiveness in patients with breast cancer.