Study on the characteristics of contrast-enhanced ultrasound and its utility in assessing the microvessel density in ovarian tumors or tumor-like lesions

Ultrasonographic and clinicopathological features of pelvic yolk sac tumors in women: a single-center retrospective analysis

Objectives

Yolk sac tumors (YSTs) are rare and highly malignant ovarian malignancies that have a very poor prognosis. The aim of this study is to delineate the ultrasound and clinicopathological features of female pelvic YSTs to better understand the disease.

Methods

This study was a retrospective analysis of the clinicopathological and ultrasound imaging data from 16 YST patients who received treatment at our hospital between January 2012 and August 2023. Then, the ultrasound imaging characteristics were compared with pathological findings.

Results

Among the 16 patients, various degrees of serum AFP increase were observed, and CA125 levels increased in 58.33% (7 out of 12) of patients. Thirteen patients (81.25%) had tumors located in ovary, two patients (12.5%) had tumors located in the sacrococcygeal region, and one patient (6.25%) had tumors located in the mesentery. Pathologically, nine patients presented with simple yolk sac tumors and seven with mixed germ cell tumors. According to the ultrasound manifestations, YST lesions can be classified into three types. (1) the cystic type, was diagnosed in two patients who presented with a large cystic mass with regular morphology and clear boundary and dense liquid within the cyst; and (2) the cystic-solid mixed type, was diagnosed in 4 patients. On 2D ultrasound, the lesions showed a cystic-solid mixed echo, and color Doppler showed a rich blood flow signal in the solid region and cystic separation. made up of four cases. (3) In ten patients with the solid type, 2D ultrasound showed solid uniform echoes with clear boundaries. The "fissure sign" was observed in the lesion. Color Doppler displayed rich blood flow in the solid part, and PW showed low to moderate resistance index of artery (RI:0.21-0.63). On contrast-enhanced ultrasound (CEUS), rapid and high enhancement in the solid part and cystic separation was observed in 2 patients.

Conclusions

Combining ultrasound features with clinical information and tumor markers provides reliable clues for the diagnosis of YST. The application of two-dimensional ultrasound and CEUS combined with patient tumor marker levels can provide a robust reference for determining the necessity of fertility-preserving surgery and postoperative chemotherapy, which can improve clinical decision-making and patient consultation.

Quantitative analysis using intraoperative contrast-enhanced ultrasound in adult-type diffuse gliomas with isocitrate dehydrogenase mutations: association between hemodynamics and molecular features

PURPOSE

The relationship between contrast-enhanced ultrasound (CEUS) hemodynamics and the molecular biomarkers of adult-type diffuse gliomas, particularly isocitrate dehydrogenase (IDH), remains unclear. This study was conducted to provide a comprehensive description of the vascularization of adult-type diffuse gliomas using quantitative indicators. Additionally, it was designed to identify any variables with the potential to intraoperatively predict IDH mutation status.

METHODS

This prospective study enrolled patients with adult-type diffuse gliomas between November 2021 and September 2022. Intraoperative CEUS was performed, and CEUS videos were recorded for 90-second periods. Hemodynamic parameters, including the peak enhancement (PE) difference, were calculated based on the time-intensity curve of the region of interest. A differential analysis was performed on the CEUS parameters with respect to molecular biomarkers and grades. Receiver operating characteristic curves for various parameters were analyzed to evaluate the ability of those parameters to predict IDH mutation status.

RESULTS

Sixty patients with adult-type diffuse gliomas were evaluated. All hemodynamic parameters, apart from rising time, demonstrated significant differences between IDH-mutant and IDH-wildtype adult-type diffuse gliomas. The PE difference emerged as the optimal indicator for differentiating between IDH-wildtype and IDH-mutant gliomas, with an area under the curve of 0.958 (95% confidence interval, 0.406 to 0.785). Additionally, the hemodynamic parameters revealed significant differences across both grades and types of adult-type diffuse gliomas.

CONCLUSION

Hemodynamic parameters can be used intraoperatively to effectively distinguish between IDHwildtype and IDH-mutant adult-type diffuse gliomas. Additionally, quantitative CEUS equips neurosurgeons with dynamic perfusion information for various types and grades of adult-type diffuse gliomas.

O-RADS combined with contrast-enhanced ultrasound in risk stratification of adnexal masses

BACKGROUND

Ovarian-Adnexal Reporting and Data System (O-RADS) for ultrasound is a lexicon and risk stratification system that includes all risk categories and relevant management recommendation. It has high sensitivity in diagnosing malignant adnexal tumors, but the specificity is lower.

OBJECTIVE

To explore the value of O-RADS combined with contrast-enhanced ultrasound (CEUS) in risk stratification of adnexal masses.

METHODS

A retrospective study was performed on 85 patients with 100 adnexal masses that preoperatively underwent conventional ultrasound as well as CEUS examination and obtained the postoperative pathological results. The masses were classified into O-RADS2, 3, 4, and 5 by conventional ultrasound. After contrast enhancement, the classification of O-RADS was adjusted according to CEUS imaging features. The O-RADS 2 and 3 lesions with suspected malignant features like irregular blood vessels or internal inhomogeneous hyperenhancement were upgraded to O-RADS 4, and the O-RADS 4 lesions with the above features were upgraded to O-RADS 5. The O-RADS 4 lesions with suspicious benign angiographic features like a regular vessel, interior hypoenhancement or non-enhancement were downgraded to O-RADS 3; the O-RADS 5 lesions with rim ring-enhancement and interior non-enhancement were downgraded to O-RADS 3. The sensitivity, specificity, accuracy, PPV, NPV, and AUC of the two methods were compared, taking pathological results as the gold standard.

RESULTS

The sensitivity, specificity, accuracy, PPV, NPV, and AUC of O-RADS and O-RADS combined with CEUS in the diagnosis of malignant adnexal tumors were 96.6%, 66.2%, 75.0%, 53.8%, 97.9%, 0.910 and 96.6%, 91.5%, 93.0%, 82.4%, 98.5%, 0.962, respectively. The specificity, accuracy, PPV, and AUC of O-RADS combined with CEUS were considerably higher than those of O-RADS (P < 0.01). Furthermore, both methods had excellent sensitivity and NPV but there were no significant differences between them(P > 0.05).

CONCLUSION

Combination of O-RADS and CEUS can significantly improve the specificity and PPV in diagnosing malignant adnexal tumors. It seems promising in the clinical application of risk stratification of adnexal masses.

Comparative Study of the Efficacy of the Ovarian-Adnexa Reporting and Data System Ultrasound Combined With Contrast-Enhanced Ultrasound and the ADNEX MR Scoring System in the Diagnosis of Adnexal Masses

OBJECTIVE

The aims of this study were to develop the Ovarian-Adnexa Reporting and Data System (O-RADS) and O-RADS + contrast-enhanced ultrasound (O-RADS CEUS) scoring system to distinguish adnexal masses (AMs) and to compare the diagnostic efficacy of these systems with that of a magnetic resonance imaging scoring system (ADNEX MR).

METHODS

We retrospectively evaluated 278 ovarian masses from 240 patients between May 2017 and July 2022. Pathology and adequate follow-up were used as reference standards for comparing the validity of O-RADS, O-RADS CEUS and ADNEX MR scoring to diagnose AMs. Area under the curve (AUC), sensitivity and specificity were calculated. The inter-class correlation coefficient (ICC) was calculated to evaluate inter-reader agreement (IRA) between the two sonographers and two radiologists who analyzed the findings with the three modalities.

RESULTS

The AUCs of O-RADS, O-RADS CEUS and ADNEX MR scores were 0.928 (95% confidence interval [CI]: 0.895-0.956), 0.951(95% CI: 0.919-0.973) and 0.964 (95% CI: 0.935-0.983), respectively. Their sensitivities were 95.7%, 94.3 and 91.4%, and their specificities were 81.3%, 92.3% and 97.1%, respectively. The three modalities had accuracies of 84.9%, 92.8% and 95.7%, respectively. O-RADS had the highest sensitivity but significantly lower specificity (p < 0.001), whereas the ADNEX MR scoring had the highest specificity (p < 0.001) but lower sensitivity (p < 0.001). O-RADS CEUS had intermediate sensitivity and specificity (p < 0.001).

CONCLUSION

The addition of CEUS significantly improves the efficacy of O-RADS in diagnosing AMs. The diagnostic efficacy of the combination is comparable to that of the ADNEX MR scoring system.

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.

Comparison of contrast-enhanced ultrasound, IOTA simple rules and O-RADS for assessing the malignant risk of sonographically appearing solid ovarian masses

PURPOSE

To explore the diagnostic accuracy of ovarian solid tumors by 2D ultrasound and contrast-enhanced ultrasound (CEUS).

MATERIALS AND METHODS

We retrospectively evaluated the CEUS characteristics of prospectively enrolled 16 benign and 19 malignant ovarian solid tumors. We performed International Ovarian Tumor Analysis (IOTA) simple rules and Ovarian-Adnexal Reporting and Data System (O-RADS) for all lesions, and evaluated their characteristics on CEUS. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of IOTA simple rules, O-RADS and CEUS in the diagnosis of ovarian solid malignancies were calculated.

RESULTS

The combination of time to wash-in earlier than or equal to the myometrium, time to PI earlier than or equal to the myometrium and the intensity at peak were higher than or equal to myometrium with sensibility of 0.947, specificity of 0.938, and PPV of 0.947, NPV of 0.938 which were higher than IOTA simple rules and O-RADS. According to the definition of ovarian solid tumor, the diagnostic accuracy of O-RADS 3 and CEUS were both 100%, CEUS improved the accuracy of O-RADS 4 from 47.4% to 87.5%, the accuracy of solid smooth CS 4 in O-RADS 5 and CEUS were both 100%, CEUS improved the accuracy of solid irregular in O-RADS 5 from 70% to 87.5%.

CONCLUSION

For ovarian solid tumors that are difficult to distinguish between benign and malignant, the introduction of CEUS on the basis of 2D classification criteria can significantly improve the diagnostic accuracy.

Contrast-enhanced ultrasonography for differential diagnosis of adnexal masses

Background

Quantitative contrast-enhanced ultrasonography parameters are affected by various factors. We evaluated corrected quantitative contrast enhanced ultrasonography in differentiating benign adnexal tumors from malignant tumors.

Methods

Patients with adnexal masses who underwent conventional and contrast-enhanced ultrasonography were included. Contrast-enhanced ultrasonography parameters such as base intensity, arrival time, peak intensity, time to peak intensity, ascending slope, and descending slope were measured. Corrected (time to peak intensity − arrival time) _mass/(time to peak intensity − arrival time) _uterus and (peak intensity − base intensity) _mass/(peak intensity − base intensity) _uterus were calculated. Lesions were confirmed by pathologic examination of surgical specimens.

Results

This study included 31 patients with 35 adnexal lesions including 20 (57.10%) benign and 15 (42.90%) malignant lesions. The corrected contrast-enhanced ultrasonography quantitative parameters in lesions were statistically different between malignant and benign groups (P<0.05). The optimal cut-off value for (time to peak intensity − arrival time) _mass/(time to peak intensity − arrival time) _uterus, ascending slope, and (peak intensity − base intensity) _mass/(peak intensity − base intensity) _uterus, and descending slope for differentiating malignant adnexal masses from benign tumors were 1.05 (area under curve: 0.93, P<0.05), 1.11 (area under curve: 0.83, P<0.05), 0.82 (area under curve: 0.73, P<0.05), and −0.27 (area under curve: 0.66, P=0.16), with sensitivity and specificity of 93.33% and 85.00%, 86.67% and 75.00%, 86.67% and 60.00%, and 54.55% and 66.67%, respectively.

Conclusions

Corrected contrast-enhanced ultrasonography parameters provide practical differential diagnosis value of adnexal lesions with high reliability for sonologists.

Characterization of Adnexal Masses Using Contrast-Enhanced Subharmonic Imaging: A Pilot Study

OBJECTIVES

This pilot study evaluated whether contrast-enhanced subharmonic imaging (SHI) could be used to characterize adnexal masses before surgical intervention.

METHODS

Ten women (with 12 lesions) scheduled for surgery of an ovarian mass underwent an SHI examination of their adnexal region using a modified LOGIQ E9 scanner (GE Healthcare, Waukesha, WI) with an endocavitary transducer, in which digital clips were acquired by pulse destruction-replenishment SHI across the lesions. Time-intensity curves were created offline to quantitatively evaluate SHI parameters (fractional tumor perfusion, peak contrast intensity, time to peak contrast enhancement, and area under the time-intensity curve), which were compared to pathologic characterizations of the lesions.

RESULTS

Of the 12 masses, 8 were benign, and 4 were malignant. A qualitative analysis of the SHI images by an experienced radiologist resulted in diagnostic accuracy of 70%, compared to 56% without contrast, whereas an inexperienced radiologist improved from 50% to 58% accuracy, demonstrating the benefit of SHI. A quantitative analysis of SHI parameters produced diagnostic accuracy as high as 81%. Peak contrast intensity was significantly greater in malignant than benign masses (mean ± SD, 0.109 ± 0.088 versus 0.046 ± 0.030 arbitrary units; P = .046). Malignant masses also showed significantly greater perfusion than benign masses (24.79% ± 25.34% versus 7.62% ± 6.50%; P = .045). When the radiologist reads were combined with the most predictive quantitative SHI parameter (percent perfusion), diagnostic accuracy improved to 84% for the experienced radiologist and 96% for the novice radiologist.

CONCLUSIONS

Results indicate that SHI for presurgical characterization of adnexal masses may improve the determination of malignancy and diagnostic accuracy, albeit based on a small sample size.

Dynamic Contrast-Enhanced Ultrasound of Gastric Cancer: Correlation with Perfusion CT and Histopathology

Objective

To assess the relationship between contrast-enhanced ultrasound (CEUS) parameters and perfusion CT (PCT) parameters of gastric cancers and their correlation with histologic features.

Materials and Methods

This prospective study was approved by our Institutional Review Board. We included 43 patients with pathologically-proven gastric cancers undergoing CEUS using SonoVue® (Bracco) and PCT on the same day. Correlation between the CEUS parameters (peak intensity [PI], area under the curve [AUC], rise time [RT] from 10% to 90% of PI, time to peak [TTP_US], and mean transit time [MTT_US]) and PCT parameters (blood flow, blood volume, TTP_CT, MTT_CT, and permeability surface product) of gastric cancers were analyzed using Spearman's rank correlation test. In cases of surgical resection, the CEUS and PCT parameters were compared according to histologic features using Mann-Whitney test.

Results

CEUS studies were of diagnostic quality in 88.4% (38/43) of patients. Among the CEUS parameters of gastric cancers, RT and TTP_US showed significant positive correlations with TTP_CT (rho = 0.327 and 0.374, p = 0.045 and 0.021, respectively); PI and AUC were significantly higher in well-differentiated or moderately-differentiated tumors (n = 4) than poorly-differentiated tumors (n = 18) (p = 0.026 and 0.033, respectively), whereas MTT_CT showed significant differences according to histologic types (poorly cohesive carcinoma [PCC] vs. non-PCC), T-staging (≤ T2 vs. ≥ T3), N-staging (N0 vs. N-positive), and epidermal growth factor receptor expression (≤ faint vs. ≥ moderate staining) (p values < 0.05).

Conclusion

In patients with gastric cancers, CEUS is technically feasible for the quantification of tumor perfusion and may provide correlative and complementary information to that of PCT, which may allow prediction of histologic features.

Association between quantitative parameters of CEUS and Sall4/Wnt/β-catenin signaling in patients with hepatocellular carcinoma

Objectives: In this study, we aim to investigate the correlations of quantitative parameters of contrast-enhanced ultrasonography (CEUS) and Spalt-Like Transcription Factor 4 (Sall4)/Wnt/β-catenin signaling pathway with clinicopathological features and prognosis of patients with hepatocellular carcinoma (HCC).

Methods: The CEUS was performed to detect the liver function and the prognosis of patients. The expression of Sall4, WNT3a and β-catenin was evaluated using immunohistochemical staining. Sall4, WNT3a and β-catenin mRNA expression was measured by SYBR green qPCR assay.

Results: We found that the mRNA and protein expression of Sall4, WNT3a and β-catenin in the HCC tissues were significantly upregulated compared with the adjacent normal tissues. Upregulation of these proteins was associated with tumor differentiation, TNM stage, tumor size, vascular invasion and liver cirrhosis of HCC patients. In addition, we found that decreased time to peak and washout time and increased peak intensity and area under the curve of CEUS in the HCC were also correlated with TNM stage, tumor size and vascular invasion. Moreover, Sall4, WNT3a and β-catenin protein were significantly associated with the TTP, PI, AUC, and WOT.

Conclusion: This study suggests that quantitative parameters of CEUS and Sall4/Wnt/β-catenin signaling may be helpful for early diagnosis and prognosis prediction of HCC patients.

Contrast-enhanced ultrasound in the diagnosis of endometrial carcinoma: A meta-analysis

The present study evaluated the diagnostic value of contrast-enhanced ultrasound (CEUS) in endometrial carcinoma (EC). Articles published until 31 January 2017 were retrieved from PubMed, EMBASE, Elsevier, Springer and Google scholar, with the following inclusion criteria: i) The accuracy (sensitivity and specificity) of CEUS in the diagnosis of EC was evaluated; ii) a gold standard was adopted to treat and confirm EC, including surgery, histopathology and appropriate follow-up (as included in the meta-analysis); iii) the data allowed for construction of a 2×2 table of positives, false-positives, negatives and false-negatives. Pooled estimates of sensitivity, specificity, risk ratios and diagnostic odds ratios (DOR) were calculated in the present meta-analysis of the accuracy of CEUS in diagnosing EC. The summary receiver-operating characteristics (sROC) curve was also constructed. Among the 93 relevant articles, 7 studies were finally selected according to the inclusion criteria with a sample size of n=275. The pooled sensitivity of CEUS in the diagnosis of EC was 84% [95% confidence interval (CI), 0.78-0.88], while the pooled specificity was 90% (95% CI, 0.86-0.92). The positive likelihood ratio (+LR) of CEUS was 8.0 (95% CI, 5.9-10.8) and the negative likelihood ratio (-LR) was 0.18 (95% CI, 0.13-0.25). The DOR was 44 (95% CI, 26-77). The area under the sROC curve was 0.93 with specificity of 0.90 (0.86-0.92) and sensitivity of 0.84 (0.78-0.88) for the summary operating point. Moderate heterogeneity was observed for sensitivity, specificity and DOR with I² values of 32.56, 34.68 and 41.2%, respectively. No significant publication bias was observed for the DOR of CEUS. In conclusion, the present meta-analysis indicates that CEUS is valuable in the diagnosis of EC. Additional clinical data and studies are still required to confirm these results and to further develop the diagnostic application of CEUS in EC.

Combination of serum CA19-9 and CA125 levels and contrast-enhanced ultrasound parametric data facilitates to differentiate ovarian serous carcinoma from ovarian malignant epithelial cancer

Ovarian serous carcinoma (OSC) is semimalignant ovarian tumors that localized in the ovary at the initial presentation, and can be surgically resected in an excellent prognosis. In contrast, surgical treatment plus adjuvant chemotherapy for ovarian malignant epithelial cancer (OMEC) is the standard treatment stratagem that is painful with poor prognosis and cost quite expensively. Thus, the accurate preoperative differentiation of OSC from OMEC is important for determining the treatment methods and decreasing the cost for individual patients. This study aims to determine whether contrast enhanced ultrasound (CEUS) together with CA19-9/CA125 can improve the ability to differentiate ovarian serous carcinoma from ovarian malignant epithelial cancer. The positive rate of cancer antigen (CA) 199 and CA125 in ovarian malignant epithelial tumors was 68% and 94%, respectively, which was a higher incidence than in the serous carcinoma. The mean serum CA19-9 and CA125 concentration was significantly higher in the patients with ovarian malignant epithelial tumors (CA19-9, 514.0 ± 104.8 U/mL; CA125, 440.0 ± 154.8 U/mL) than that in the patients with ovarian serous carcinoma (CA19-9, 58.0 ± 14.3 U/mL; CA125, 63.0 ± 25.8 U/mL). The time to peak in ovarian serous carcinoma was significantly longer than in ovarian malignant epithelial tumors. However, the peak intensity, area under the curve, and washout time in ovarian serous carcinoma were significantly lower than in ovarian malignant epithelial tumors. The addition of CA19-9/CA125 increased the sensitivities from 79% CEUS only to 85% for CEUS plus CA19-9/CA125 data, and increased the specificities from 65% CEUS only to 91% for CEUS plus the CA19-9/CA125 information. Thus, the addition of the serum CA19-9/CA125 levels to parametric CEUS data was of significant diagnostic value for differentiating OSC from OMEC.

Analysis of Contrast-Enhanced Ultrasound Perfusion Patterns and Time-Intensity Curves for Metastatic Lymph Nodes From Lung Cancer: Preliminary Results

OBJECTIVES

To retrospectively summarize the similarities and differences in contrast-enhanced ultrasound (US) findings for lymph node metastasis from adenocarcinoma, squamous carcinoma, and small cell lung cancer.

METHODS

Patients who had received contrast-enhanced US examinations and had a histologic diagnosis of supraclavicular lymph node metastasis from lung cancer were included. The perfusion patterns on contrast-enhanced US images and time-intensity curve parameters were analyzed for the different pathologic types. The microvascular density and microvascular diameter were evaluated.

RESULTS

Totally, 61 patients were enrolled in this study, including 26 cases with lung squamous carcinoma, 26 with lung adenocarcinoma, and 9 with small cell lung cancer. Contrast-enhanced US perfusion showed no significant differences in enhancement uniformity during the arterial phase and in the presence of unenhanced areas of metastatic lymph nodes with the 3 different pathologic origins (P > .05), but fewer unenhanced areas could be seen in metastatic lymph nodes from adenocarcinoma. The analysis of the time-intensity curve parameters showed that there were significant differences in the peak intensity between metastatic lymph nodes from lung squamous carcinoma and lung adenocarcinoma (P < .05). The microvascular density of metastatic lymph nodes from adenocarcinoma was significantly higher than that of metastatic lymph nodes from squamous carcinoma and small cell lung cancer (P < .001; P = .0444), whereas the microvascular diameter of metastatic lymph nodes from adenocarcinoma was significantly smaller than that from squamous carcinoma and small cell lung cancer (P = .0277; P < .001).

CONCLUSIONS

Effects of the pathologic diagnosis should be considered when analyzing quantitative parameters of metastatic lymph nodes during contrast-enhanced US examinations, even in the same organ.

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.

Correlations of microvascular blood flow of contrast-enhanced ultrasound and HGF/c-Met signaling pathway with clinicopathological features and prognosis of patients with hepatocellular carcinoma

The study is designed to explore the correlations of microvascular blood flow of contrast-enhanced ultrasound (CEUS) and hepatocyte growth factor (HGF)/c-Met signaling pathway with clinicopathological features and prognosis of patients with hepatocellular carcinoma (HCC). One hundred and eighteen patients pathologically diagnosed as primary HCC were selected. All HCC patients underwent CEUS examination before operation. HCC tissues and adjacent normal tissue specimens were obtained to detect the protein rates of HGF and c-Met expressions by immunohistochemistry. The mRNA expressions of HGF and c-Met were detected by quantitative real-time polymerase chase reaction assay. The microvessel density (MVD) was tested by CD34 immunohistochemistry. Compared with liver parenchyma, the HCC lesions had higher MVD, preoperative peak intensity (PI), area under the curve (AUC), lower preoperative time to peak (TTP), and washout time (WOT). Compared with adjacent normal tissues, the protein and mRNA expressions of HGF were reduced in HCC tissues, but the protein and mRNA expressions of c-Met and MVD were increased. The protein expressions of HGF and c-Met exhibited evident correlations with TNM stage, tumor size, vascular invasion, liver cirrhosis, and hepatitis B virus and hepatitis C virus infection of HCC patients. The tumor size and number, vascular invasion, the protein expressions of HGF and c-Met, and MVD were associated with the TTP, PI, WOT, and AUC of CEUS in HCC patients. The protein expressions of HGF and c-Met, MVD and preoperative PI revealed negative associations with the prognosis of HCC patients. In conclusion, quantitative parameters of CEUS and HGF/c-Met signaling pathway-related proteins may be helpful for early diagnosis and prognosis prediction of HCC patients.

Quantitative contrast-enhanced ultrasonography for the differential diagnosis of endometrial hyperplasia and endometrial neoplasms

The present study aimed to investigate the feasibility of applying contrast-enhanced ultrasonography (CEUS) imaging technology for distinguishing between benign and malignant endometrial lesions, and to screen markers that could be correlated with the pathological results. In this study, endometrial diseases were diagnosed by biopsy under hysteroscopy and CEUS examinations. The intensity and time parameters of the time-intensity curve (TIC) were analyzed. The mean arrival time (AT), time-to-peak (TTP), rise time (RT), washout half-time and clearance half-time of malignant lesions were shorter than those of benign lesions (P<0.05), whereas the average peak intensity (PI) and enhancement intensity (EI) of malignant lesions were higher than those of benign lesions (P<0.05). The receiver operating characteristic curve showed the following cut-off values: PI, 29.2 dB; EI, 21.35 dB; AT, 12.75 sec; TTP, 26.75 sec; RT, 13.2 sec; clearance half-time, 89.3 sec; and washout half-time, 75.45 sec. The lesions with PI, an EI higher than that of the cut-off and lesions with an AT, TTP, RT, half clearing time and washout half-time shorter than the cut-off were considered malignant. The TTP, RT and half clearing time were negatively correlated with microvessel density (MVD), i.e., MVD was higher when the TTP, RT and half clearing time were shorter. Overall, changes in the enhancement and clearing of lesions could be quantitatively analyzed by CEUS TIC and further discriminate benign from malignant lesions. In the present study, CEUS appeared to indirectly reflect blood vessel changes inside the lesions and provided a pre-operative non-invasive fast imaging method for the diagnosis of endometrial disease.

Development and Validation of a Histological Method to Measure Microvessel Density in Whole-Slide Images of Cancer Tissue

Despite all efforts made to develop predictive biomarkers for antiangiogenic therapies, no unambiguous markers have been identified so far. This is due to among others the lack of standardized tests. This study presents an improved microvessel density quantification method in tumor tissue based on stereological principles and using whole-slide images. Vessels in tissue sections of different cancer types were stained for CD31 by an automated and validated immunohistochemical staining method. The stained slides were digitized with a digital slide scanner. Systematic, uniform, random sampling of the regions of interest on the whole-slide images was performed semi-automatically with the previously published applications AutoTag and AutoSnap. Subsequently, an unbiased counting grid was combined with the images generated with these scripts. Up to six independent observers counted microvessels in up to four cancer types: colorectal carcinoma, glioblastoma multiforme, ovarian carcinoma and renal cell carcinoma. At first, inter-observer variability was found to be unacceptable. However, after a series of consensus training sessions and interim statistical analysis, counting rules were modified and inter-observer concordance improved considerably. Every CD31-positive object was counted, with exclusion of suspected CD31-positive monocytes, macrophages and tumor cells. Furthermore, if interconnected, stained objects were considered a single vessel. Ten regions of interest were sufficient for accurate microvessel density measurements. Intra-observer and inter-observer variability were low (intraclass correlation coefficient > 0.7) if the observers were adequately trained.

Microflow imaging of contrast-enhanced ultrasound for evaluation of neovascularization in peripheral lung cancer

The aim of this study was to investigate the role of microflow imaging (MFI) of contrast-enhanced ultrasound (CEUS) for evaluating microvascular architecture of different types of peripheral lung cancer (PLC) and to explore the correlated pathological basis.Ninety-five patients with PLC were enrolled in this study. Two radiologists independently evaluated the microvascular architecture of PLC with MFI. The interobserver agreement was measured with Kappa test. The diagnosis value of MFI was calculated. With pathological analysis, the correlation between MFI and microvascular density (MVD)/microvascular diameter (MD) was evaluated.Of the 95 PLCs, MFI were mainly classified "dead wood" (27.4%, 25.3%), "vascular" (47.4%, 49.5%), and "cotton" (20.0%, 20.0%) patterns by the 2 readers. Kappa test showed a good agreement between the 2 readers (Kappa = 0.758). The "dead wood" can be regarded as a specific diagnostic factor for squamous carcinoma; the sensitivity, specificity, and accuracy was 62.9%, 93.3%, and 82.1%, respectively. The "vascular" and "cotton" patterns correlated well with adenocarcinoma and SCLC (small cell lung cancer); diagnostic sensitivity, specificity, and accuracy were 86.7%, 65.7%, and 78.9%, respectively. MVD of "dead wood" was lower than "vascular" and "cotton," while MD was bigger than the other 2 patterns (P < 0.05). There was a good correlation between MFI and histopathological types of PLC as well as between MFI and MVD/MD (P < 0.05).MFI has the advantage to display the microvascular architecture of PLCs and might become a promising diagnostic method of histopathological types of PLC. MFI features also correlated well with its pathological basis, including MVD and MD.

Mathematical Models of Contrast Transport Kinetics for Cancer Diagnostic Imaging: A Review

Angiogenesis plays a fundamental role in cancer growth and the formation of metastasis. Novel cancer therapies aimed at inhibiting angiogenic processes and/or disrupting angiogenic tumor vasculature are currently being developed and clinically tested. The need for earlier and improved cancer diagnosis, and for early evaluation and monitoring of therapeutic response to angiogenic treatment, have led to the development of several imaging methods for in vivo noninvasive assessment of angiogenesis. The combination of dynamic contrast-enhanced imaging with mathematical modeling of the contrast agent kinetics enables quantitative assessment of the structural and functional changes in the microvasculature that are associated with tumor angiogenesis. In this paper, we review quantitative imaging of angiogenesis with dynamic contrast-enhanced magnetic resonance imaging, computed tomography, and ultrasound.

Comparison of Uterine Receptivity between Fertile and Unexplained Infertile Women by Assessment of Endometrial and Subendometrial Perfusion Using Contrast-Enhanced Ultrasound: Which Index is Better--Peak Intensity or Area under the Curve?

The goal of this study was to compare uterine receptivity between women with normal fertility and those with unexplained infertility during natural cycles by assessment of endometrial and subendometrial perfusion using contrast-enhanced ultrasound (CEUS). We wanted to determine the better index: peak intensity (PI) or area under the curve (AUC). Thirty women with unexplained infertility were recruited into the study group, and 30 women with normal fertility were recruited into the control group. All women underwent CEUS during the late proliferative phase, ovulation phase, and implantation window of a menstrual cycle. Endometrial PI, endometrial AUC, subendometrial PI and subendometrial AUC were analyzed. In the late proliferative phase, the control group had a significantly higher endometrial PI (p < 0.001) as well as subendometrial PI (p < 0.001) and AUC (p = 0.004) than the study group. In the ovulation phase, the control group had a significantly higher endometrial PI (p < 0.001) and AUC (p = 0.021), as well as subendometrial PI (p < 0.001) and AUC (p = 0.003). During the implantation window, there were no significant differences between the two groups. Only subendometrial PI underwent a significant periodic change during the menstrual cycle in both groups. This finding was further confirmed by evaluation of the microvessel density of endometria. In conclusion, CEUS can be used to assess endometrial and subendometrial perfusion to evaluate uterine receptivity. Subendometrial PI was the most sensitive index compared with endometrial PI, endometrial AUC and subendometrial AUC.

Role of contrast-enhanced ultrasound (CEUS) in the diagnosis of endometrial pathology

Ultrasound is the reference imaging procedure used for the exploration of endometrial pathology. As medical procedures improve and the requirements of modern medicine become more demanding, gray-scale ultrasound is insufficient in establishing gynecological diagnosis. Thus, more complex examination techniques are required: Doppler ultrasound, contrast-enhanced ultrasound (CEUS), 3D ultrasound, etc. Contrast-enhanced ultrasound is a special examination technique that gains more and more ground. This allows a detailed real-time evaluation of microcirculation in a certain territory, which is impossible to perform by Doppler ultrasound. The aim of this review is to synthesize current knowledge regarding CEUS applications in endometrial pathology, to detail the technical aspects of endometrial CEUS and the physical properties of the equipment and contrast agents used, as well as to identify the limitations of the method.

Diagnostic performance of contrast-enhanced ultrasound for ovarian cancer: a meta-analysis

This meta-analysis is the first study aimed at assessing the overall diagnostic performance of contrast-enhanced ultrasound for ovarian cancer. PubMed, Embase and Medline databases were systematically searched for relevant articles published up to June 2014. Data were pooled to yield summary sensitivity, specificity, diagnostic odds ratio and receiver operating characteristic curves using Meta-Disc Version 1.4 software. Ten independent studies with 579 ovarian tumors were enrolled in this meta-analysis. The pooled sensitivity, specificity and diagnostic odds ratio statistics were 0.89 (0.83-0.94), 0.91 (0.88-0.93) and 91.70 (41.41-203.05), respectively, and the area under the summary receiver operating characteristic curve was 0.9619 (standard error: 0.0125), all indicating that contrast-enhanced ultrasound has high diagnostic accuracy in differentiation of malignant from benign ovarian tumors.

Combination of 2- and 3-dimensional contrast-enhanced transvaginal sonography for diagnosis of small adnexal masses

OBJECTIVES

The purpose of this study was to evaluate the efficacy of the combination of 2-dimensional (2D) and 3-dimensional (3D) contrast-enhanced sonography in discriminating between benign and malignant small adnexal masses.

METHODS

Selected patients were evaluated with both 2D and 3D contrast-enhanced sonography after conventional sonography before undergoing any surgery. Time-intensity curves for 2D contrast-enhanced sonography were constructed by using contrast-enhanced sonographic software. A vascular perfusion characteristic analysis was achieved by 2D and 3D contrast-enhanced sonography. Results were finally verified by surgery.

RESULTS

Forty-seven cases of benign and 10 cases of malignant small adnexal masses were discovered. Significant differences in perfusion patterns, time-intensity curve shapes for 2D contrast-enhanced sonography, grayscale contrast-enhanced sonography, and blood flow imaging on 3D contrast-enhanced sonography were observed between benign and malignant masses (P< .05). Two-dimensional contrast-enhanced sonography, 3D contrast-enhanced sonography, parallel combination of 2D and 3D contrast-enhanced sonography, and serial combination of 2D and 3D contrast-enhanced sonography all reached diagnostic sensitivity of 100% for discriminating benign from malignant masses, whereas specificity values were 61.7%, 63.8%, 68.1%, and 57.4%, respectively. Areas under the receiver operating characteristic curves were 0.809, 0.819, 0.840, and 0.787.

CONCLUSIONS

Two-dimensional contrast-enhanced sonography is of high value in distinguishing malignant from benign small adnexal masses; 3D contrast-enhanced sonography provides richer and more useful information for evaluation of these masses. Diagnostic sensitivity of 100% can be achieved when using a serial combination of 2D and 3D contrast-enhanced sonography, although specificity needs further improvement.

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.

Quantitative contrast-enhanced ultrasound comparison between inflammatory and fibrotic lesions in patients with Crohn's disease

The aim of this study was to determine whether there are differences in absolute blood flow between patients with Crohn's disease with inflammation or fibrosis using contrast-enhanced ultrasound. Eighteen patients with fibrotic disease and 19 patients with inflammation were examined. Video sequences of contrast data were analyzed using a pharmacokinetic model to extract the arterial input and tissue residue functions with a custom software, enabling calculation of the absolute values for mean transit time, blood volume and flow. Feasibility of the examination was 89%. The fibrosis group had lower blood volume (0.9 vs. 3.4 mL per 100 mL tissue; p = 0.001) and flow (22.6 vs. 45.3 mL/min per 100 mL tissue; p = 0.003) compared with the inflammation group. There was no significant difference in mean transit time (3.9 vs. 5.5 s). In conclusion, absolute perfusion measurement in the gastrointestinal wall using contrast-enhanced ultrasound is feasible. There seems to be reduced blood volume and blood flow in patients with fibrotic disease.

Effects of low-frequency ultrasound and microbubbles on angiogenesis-associated proteins in subcutaneous tumors of nude mice

It has been shown that 1 and 3 MHz low-intensity ultrasound was able to affect the fragile and leaky angiogenic blood vessels in a tumor. However, the biological effects of 21 kHz low-intensity ultrasound on tumors remain unclear. The aim of the present study was to explore the effects of 21 kHz ultrasound with microbubbles on the regulation of vascular endothelial growth factor (VEGF), cyclooxygenase-2 (COX-2) and apoptosis in subcutaneous prostate tumors in nude mice. The study included three parts, each with 20 tumor-bearing nude mice. Twenty nude mice were divided into four groups: control (sham treatment), microbubble ultrasound contrast agent (UCA), low-frequency ultrasound (US) and US+UCA groups. The UCA used was a microbubble contrast agent (SonoVue). The parameter of ultrasound: 21 kHz, an intensity of 26 mW/cm2, 40% duty cycle (on 2 sec, off 3 sec), 3 min, once every other day for 2 weeks. In the first study, all subcutaneous tumors were examined by contrast-enhanced ultrasonography (CEUS) at the initiation and completion of the experiments. Peak intensity (PI), time to peak intensity (TTP) and area under the curve (AUC) on the time intensity curve (TIC) were analyzed. In the second study, the intensity of VEGF and COX-2 protein expression in the vascular endothelium and cytoplasm was evaluated using immunohistochemistry and laser confocal microscopy. In the third study, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay was used for the evaluation of cell apoptosis in tumor tissues. The tumor cells and vasculature were examined by transmission electron microscopy (TEM). Only in the US+UCA group, PI and AUC decreased. The intensity of COX-2 and VEGF in the US+UCA group in immunohistochemical staining and laser confocal microscopy was lower compared to that of the other three groups. More cell apoptosis was found in the US+UCA group compared to the other 3 groups. In the control, UCA and US groups, the tumors had intact vascular endothelium and vessel lumens in TEM. However, lumen occlusion of vessels was observed in the US+UCA group. Twenty-one kHz low-intensity ultrasound with microbubbles may have anti-angiogenic effects on subcutaneous tumors in nude mice.

The acute effects of exercise on the microvascular volume of Achilles tendons in healthy young subjects

BACKGROUND

Real-time harmonic contrast-enhanced ultrasound (CEU) is used in several diseases to visualize the microvascularization in various tissues, due to its high sensitivity.

AIM

The aim of the present study was to investigate whether CEU could be used to detect an increase in the microvascular volume (MV) in healthy tendon tissue in response to exercise comprising a 1-h run.

METHODS

After a bolus injection of the ultrasound contrast SonoVue(®), CEU measurements of (MV) in the Achilles tendon were taken prior to exercise, immediately after a 1-h run, and 24 h after exercise in nine healthy young subjects (seven men and two women) mean age 31 ± 4 years. In addition, the effect of 15 min of arm cycling exercise on the flow within the Achilles tendon was tested in four athletes (mean age 33 ± 6 years) using the CEU method before and after exercise.

RESULTS

The present data show a significant increase in the (MV) of the Achilles tendon for all subjects following the run compared with before exercise. No significant change in (MV) was seen in the Achilles tendon after 15-min arm cycling exercise (P = 0·96). This indicates that the increase in microvascular blood volume within the Achilles tendon in response to running is a local response.

CONCLUSION

The present data reveal that real-time harmonic CEU can be used to determine the MV of healthy Achilles tendons both at rest and after 1 h of running exercise.

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.

Effect of the combination of a cyclooxygenase-1 selective inhibitor and taxol on proliferation, apoptosis and angiogenesis of ovarian cancer in vivo

This study was designed to investigate the effects of a cyclooxygenase (COX)-1 inhibitor, SC-560, administered in combination with taxol, on the molecular mechanisms of antitumor efficacy in a SKOV-3 human ovarian carcinoma cell xenograft-bearing mouse model. The mice were treated with 6 mg/kg/day SC-560 by gavage twice every other day and 20 mg/kg taxol by intraperitoneal injection once a week for three weeks. Microvessel density (MVD) and vascular endothelial growth factor (VEGF) mRNA levels of ovarian cancer were detected in the tumor tissues using immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR), respectively. The index of proliferating and apoptotic cells in the tumor tissues was determined by staining for Ki-67 and using the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) method, respectively. On day 7 after the end of administration, the tumor volume of mice in the combination group was reduced by 55.35% compared with that of the control mice, and the difference was statistically significant (P<0.05). In the combination group, the expression of VEGF, MVD and the cell proliferation index were inhibited significantly, while the apoptotic index was notably increased (all P<0.01, compared with the control group). Our results indicate that the molecular mechanisms of the antitumor efficacy of SC-560 combined with taxol therapy may act in part by inhibiting tumor angiogenesis, reducing cell proliferation and inducing cell apoptosis.