Visualization of blood flow in small ovarian tumor vessels by transvaginal color Doppler sonography after echo enhancement with injection of Levovist

Contrast-Enhanced Sonographic Features Before and After Interventional Treatment of Ovarian Endometrial Cysts

OBJECTIVES

The purpose of this study was to assess contrast-enhanced sonography features before and after interventional treatment of ovarian endometrial cysts.

METHODS

We retrospectively analyzed 53 patients with ovarian endometrial cysts who underwent contrast-enhanced sonography before and after interventional treatment to assess the sonographic features of the cysts at these different times. The sonographic features and quantitative parameters for the cysts were compared before and after treatment.

RESULTS

The wash-in mode showed rapid annular enhancement of the cyst wall and slow wash-out with even and uneven enhancement types. Compared to the internal iliac artery, the enhancement intensity was weaker, and the wash-in and wash-out times were longer in the cyst wall; furthermore, all 5 quantitative parameters differed between the cyst wall and internal iliac artery. The wash-in and wash-out characteristics of the cysts before and after interventional treatment were almost identical. The enhancement was primarily even before treatment and uneven after treatment; the enhancement intensity was low in all cases. Although the wash-in time before and after treatment did not differ, the wash-out time for the cysts before treatment was significantly lower than that observed after treatment. Two quantitative parameters differed before and after treatment.

CONCLUSIONS

The contrast-enhanced sonographic features and quantitative parameters for the walls of ovarian endometrial cysts differed before and after ultrasound-guided interventional treatment. These characteristics could be valuable for evaluating the efficacy of interventional treatment of ovarian endometrial cysts.

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

Angiogenesis is a critical factor in tumor growth and metastasis, and microvessel density (MVD) was an important parameter for assessing vessels in tumors. However, radiologic assessment of tumor vascularity is not yet well established. In our study, we aimed at investigating the efficacy of contrast-enhanced ultrasonography (CEUS) in exploring the vascularity of the ovarian tumors or tumor-like lesions to assess the relationship between the parameters of the peak intensity (PI) and area under curve (AUC) on CEUS and MVD in ovarian masses. Compared to the contrast-enhanced ultrasound technique, conventional ultrasound shows limitation in differentiating benign and malignant ovarian tumors. The former is promising in improving the sensitivity of detecting small vessels and blood flow in ovarian tumors. Our results showed clear differences in enhancement patterns between benign and malignant ovary tumors or tumor-like lesions. The PI and AUC in the malignant tumors were significantly higher than those in the benign tumors or tumor-like lesions (p=0.001 and =0.01, respectively). The MVD was 43.1 ± 20.4 in the benign tumors or tumor-like lesions and was 65.3 ± 22.3 in the malignant ones (p= 0.01). In both the benign and malignant groups, the PI and AUC were correlated significantly with the MVD (r=0.595, p = 0.001; r =0.533, p = 0.003, respectively). The PI and AUC in CEUS can reflect the MVD in ovarin tumors. The PI and AUC of the ovarian masses in the contrast transvaginal sonography show significant correlation with the angiogenesis and may help in assessing tumor vascularity in ovarian masses.

Contrast-enhanced sonography depicts spontaneous ovarian cancer at early stages in a preclinical animal model

OBJECTIVE

Our goal was to examine the feasibility of using laying hens, a preclinical model of human spontaneous ovarian cancer, in determining the kinetics of an ultrasound contrast agent indicative of ovarian tumor-associated neoangiogenesis in early-stage ovarian cancer.

METHODS

Three-year-old White Leghorn laying hens with decreased ovarian function were scanned before and after intravenous injection of a human serum albumin-perflutren contrast agent at a dose of 5 μL/kg body weight. Gray scale morphologic characteristics, Doppler indices, the arrival time, peak intensity, and wash-out of the contrast agent were recorded and archived on still images and video clips. Hens were euthanized thereafter; sonographic predictions were compared at gross examination; and ovarian tissues were collected. Archived clips were analyzed to determine contrast parameters and Doppler intensities of vessels. A time-intensity curve per hen was drawn, and the area under the curve was derived. Tumor types and the density of ovarian microvessels were determined by histologic examination and immunohistochemistry and compared to sonographic predictions.

RESULTS

The contrast agent significantly (P < .05) enhanced the visualization of microvessels, which was confirmed by immunohistochemistry. Contrast parameters, including the time of wash-out and area under the curve, were significantly different (P < .05) between ovaries of normal hens and hens with ovarian cancer and correctly detected cancer at earlier stages than the time of peak intensity.

CONCLUSIONS

The laying hen may be a useful animal model for determining ovarian tumor-associated vascular kinetics diagnostic of early-stage ovarian cancer using a contrast agent. This model may also be useful for testing the efficacy of different contrast agents in a preclinical setting.

Diagnostic value of contrast-enhanced ultrasonography in the characterization of ovarian tumors()

INTRODUCTION

Vascularity influences the characteristics of gynecologic tumors observed with direct imaging techniques that reveal the macrovascular component of these lesions (color and power Doppler) and with indirect imaging involving the administration of contrast agents to examine the microcirculation and interstitial perfusion (contrast-enhanced computed tomography [CT] and magnetic resonance [MR] imaging). The purpose of this study was to determine whether contrast-enhanced ultrasonography (CEUS) of ovarian lesions provides useful information that cannot be obtained with conventional US.

MATERIALS AND METHODS

We used CEUS to assess 72 nonspecific adnexal lesions in 61 patients. CEUS was performed with a 4.8-ml bolus of a second-generation ultrasonographic contrast agent and dedicated imaging algorithms. For each lesion, B-mode morphology, CEUS morphology, and time/intensity curves were evaluated.

RESULTS

In 8/61 cases (13.1%) CEUS offered no additional morphovascular information. In 38/61 cases (62.3%), it provided additional information that did not modify the management of the lesion, and in 15/61 cases (24.6%) it gave additional information that modified the management of the lesion. Malignant lesions were characterized by significantly shorter times to peak enhancement (11.9 ± 3.1 s vs 19.8 ± 4.0 s p < 0.01) and significantly higher peak intensity (24.7 ± 4.2 dB vs 17.8 ± 3.3 dB p < 0.01) compared with benign lesions.

CONCLUSIONS

CEUS improves diagnostic confidence in the characterization of liquid-corpuscular lesions where conventional US is inconclusive. CEUS can be proposed as a valid alternative to CT and MR. However, information obtained by CEUS influences the therapy in a limited percentage of cases (24.6%).

Contrast-enhanced transvaginal sonography of benign versus malignant ovarian masses: preliminary findings

OBJECTIVE

The aim of this prospective study was to evaluate differences in contrast enhancement and contrast enhancement kinetics in benign versus malignant ovarian masses with pulse inversion harmonic transvaginal sonography.

METHODS

Seventeen consecutive patients with 23 morphologically abnormal ovarian masses (solid or cystic with papillary excrescences, focally thickened walls, or irregular solid areas) smaller than 10 cm received a microbubble contrast agent intravenously while undergoing pulse inversion harmonic transvaginal sonography. The following parameters were assessed in all tumors: detectable contrast enhancement, time to peak enhancement (wash-in), peak contrast enhancement, half wash-out time, and area under the enhancement curve. Tumor histologic analysis was used to distinguish benign from malignant ovarian tumors.

RESULTS

Fourteen benign masses and 9 malignancies were studied. There was a statistically significant difference in the peak enhancement (mean +/- SD, 23.3 +/- 2.8 versus 12.3 +/- 3.9 dB; P < .01), half wash-out time (139.9 +/- 43.6 versus 46.3 +/- 19.7 seconds; P < .01), and area under the enhancement curve (2012.9 +/- 532.9 versus 523.9 +/- 318 seconds(-1); P < .01) in malignant masses compared with benign disease. There was no statistically significant difference in the time to peak enhancement (26.1 +/- 6.3 versus 24.9 +/- 7.6 seconds; P = .07).

CONCLUSIONS

Overall, our data showed a significant difference in the contrast enhancement kinetic parameters between benign and malignant ovarian masses.

The role of CnTI-SonoVue in the diagnosis of ovarian masses with papillary projections: a preliminary study

OBJECTIVES

To describe sonographically the distribution patterns of a second-generation contrast agent in the microcirculation of unilocular and multilocular ovarian masses with papillary projections, and to investigate whether qualitative evaluation of the passage of the contrast agent can improve the performance of sonography in distinguishing between benign and malignant masses with papillary projections.

METHODS

Thirty-three patients with unilocular or multilocular ovarian masses with papillary projections were enrolled into the study in three clinical centers. The contrast-enhanced transvaginal examination was performed using 'Contrast Tuned Imaging' (CnTI) technology and SonoVue ultrasound contrast agent.

RESULTS

Twenty-four (73%) lesions were benign, eight (24%) were borderline ovarian tumors, and one patient presented with an endometrioid ovarian adenocarcinoma. On color and power Doppler examinations the presence of vessels was demonstrated in 17 papillary projections, while on CnTI-SonoVue examination, the presence of vessels was shown in these 17 and in six additional cases. In all cases with absent papillary perfusion after SonoVue intravenous injection, the cyst wall appeared unequivocally regular. The sensitivity and specificity of conventional color Doppler examination with regard to malignancy were 100% and 67% and the positive and negative likelihood ratios were 3.03 and 0.16, respectively. For the contrast-enhanced examination the corresponding values were 100%, 42%, 1.7 and 0.26. The difference in specificity was statistically significant (P<0.05) because 14 cases, in which papillary perfusion was detected after SonoVue injection, proved to be benign on pathological examination.

CONCLUSION

Qualitative evaluation of blood circulation in papillary projections using CnTI-SonoVue examination does not improve the discrimination of benign from borderline/malignant ovarian masses with papillary projections.

Contrast-enhanced Ultrasound in Obstetrics and Gynecology

Ultrasonography is a well-established imaging modality for evaluation of gynecologic tumors. In recent years, more sophisticated technologies like the use of intravascular contrast agents led to an improvement in the ability of the practitioner to differentiate benign from malignant masses. When we consider the safety of contrast-enhanced ultrasonography in obstetrics and gynecology, we must discuss about the effect of ultrasound contrast media on embryo and fetus. The use of ultrasound contrast media in pregnant women always concerns in the obstetricians because of the principle of not exposing a fetus to any drug. Therefore, the literature was reviewed for information about those safety and efficacy because of the uncertainty about the use of contrast media during pregnancy. Based on the limited information available, mutagenic and teratogenic effects have not been described after administration of ultrasound contrast media. No effect on the fetus has been seen after contrast media. The small potential risk associated with the nonthermal bioeffects via acoustic cavitation may be considered to prohibit the use in first trimester pregnant women. In previous studies including human trials, no evidence of adverse effect was reported. Contrast-enhanced ultrasonography could prove a useful adjunct in multiple gestations and in evaluation of uteroplacental circulation. It appears to be very promising potential in obstetrics.

Assessment of cyclic changes of microvessels in ovine ovaries using Sonovue contrast-enhanced ultrasound

Our objective was to detect variations of ovarian vascularization that occur in the estrus cycle of the ewe using an IV contrast agent. Five ewes were investigated using contrast-enhanced power Doppler after Sonovue injection at day 0, 3, 5, 10 and 13 of the cycle in two successive estrus cycles. Transvaginal ultrasound monitoring of each ewe was performed after a dose of Sonovue. Parameters derived from the time-intensity curves were compared. Quantification of the enhancement and wash-in period parameters changed significantly between ovaries and between the follicular and luteal periods of the cycle. Uptake time, wash-out time, total time of enhancement and area under the curve were the parameters with the smallest variation between ovaries. Wash-out time and area under the curve are two contrast parameters that did not change with cyclic changes. Thus, using these parameters in premenopausal women will allow more accurate detection of vascular modifications that may be associated with ovarian cancer.

Ultrasonographic contrast media: has the time come in obstetrics and gynecology?

OBJECTIVE

The aim of this work was to review the technical aspects and clinical applications of contrast media (microbubbles and nanomolecular agents) in obstetric and gynecologic ultrasonographic imaging.

METHODS

With the use of a computerized database (MEDLINE) and several Web-based search engines (Google Scholar and Copernic), relevant articles on ultrasonographic contrast media were reviewed. References cited in these articles and not obtained via the search engines were also reviewed.

RESULTS

Ultrasonographic contrast media constitute a new and expanding technology. They are frequently used, for example, in adult cardiology. Extensive research in laboratory setups, animals, and human subjects has shown their safety and huge potential as an adjunctive tool in clinical practice. They increase signals returning from insonated tissues and are particularly effective as intravascular agents, enhancing color and Doppler signals, for instance. Preliminary results in tumor imaging are encouraging. The ultrasonographic contrast media permit pharmacokinetic perfusion studies, which may be of enormous clinical importance in the study of early cancer development. Targeted imaging and therapies are becoming a reality. Microbubbles have already brought a new dimension to diagnostic ultrasonographic imaging. Many authors have described the clinical value of these agents in liver, prostate, and breast imaging, among others. Newer types of media, the nanomolecules, are now emerging as the latest in imaging enhancers as well as therapeutic agent carriers.

CONCLUSIONS

Although showing potential in imaging of the uterus and fallopian tubes as well as some obstetric applications, the contrast media, in particular the nanomolecules, seem to be most promising in ovarian cancer.

Contrast-enhanced sonography helps in discrimination of benign from malignant adnexal masses

OBJECTIVE

To investigate the potential efficacy of real-time contrast-enhanced power Doppler sonography in the differentiation of benign and malignant adnexal masses in a pilot study.

METHODS

Before surgical treatment, adnexal masses were prospectively evaluated with power Doppler sonography before and after injection of a contrast agent. Real-time postinjection sequences were computerized with time-intensity analysis software to determine an enhancement curve and contrast parameters. The intraobserver and interobserver reproducibilities of these criteria were assessed on a subsample. These contrast parameters were compared between benign and malignant tumors using logistic regression. Sensitivity and specificity were used to compare contrast parameters with sonographic and Doppler variables.

RESULTS

Ninety-nine women were included, for a total of 101 adnexal masses. There were 23 cases of ovarian malignancies and 78 benign adnexal lesions. Our procedure had excellent intraobserver and interobserver reproducibility, with an average intraclass correlation coefficient of 0.92. The time before enhancement and intensity ratio did not reliably differentiate between the benign and malignant masses. Washout times and areas under the curves were significantly greater in ovarian malignancies than in other benign tumors (P < .001), leading to sensitivity estimates between 96% and 100% and specificity estimates between 83 and 98%. Contrast parameters had slightly higher sensitivity and slightly lower specificity when compared with transvaginal sonographic variables of the resistive index and serum cancer antigen 125 levels.

CONCLUSIONS

Contrast-enhanced power Doppler imaging may easily and precisely discriminate benign from malignant adnexal lesions. Larger studies are needed to determine the appropriate use and benefits of this new procedure.

Kinetics of a US contrast agent in benign and malignant adnexal tumors

PURPOSE

To evaluate the effects of a microbubble contrast agent on the power Doppler ultrasonographic (US) examination of adnexal tumors, with a special focus on the timing of the transit of the microbubble bolus.

MATERIALS AND METHODS

Seventy patients who were suspected of having ovarian tumors were examined preoperatively with contrast material-enhanced US. Images obtained during a 5-minute examination were stored digitally, and the behavior of the contrast agent was evaluated objectively with measurement of the time-dependent image intensity at the region of interest with a computer program. A time-intensity curve in each case was derived and analyzed. The Mann-Whitney U test was used to compare intensity changes and tumor parameters in benign and malignant adnexal tumors.

RESULTS

Both the baseline and maximum power Doppler intensities, as well as the absolute and relative (percent) rise in intensity, were significantly higher (P <.001) in malignant as compared with benign tumors. The arrival time was shorter (17.5 vs 22.5 seconds; P =.005) and the duration of contrast agent effect was longer (190.4 vs 103.6 seconds; P <.001) in malignant tumors than they were in benign tumors. The area under the time-intensity curve was significantly greater in malignant tumors compared with that in benign tumors (P <.001).

CONCLUSION

After microbubble contrast agent injection, malignant and benign adnexal lesions behave differently in degree, onset, and duration of Doppler US enhancement.

Ultrasound contrast media and their use in obstetrics and gynecology

Contrast media have gained acceptance to enhance ultrasonography in many fields of medicine; in particular, cardiology. Several agents have been described and many more are being manufactured and tested. By increasing the number of strong sound scatterers, these agents improve images by increasing the amount of echoes. This is true both for grey-scale and color or Doppler imaging. Their use in obstetrics is very limited at the moment because of safety issues. In a laboratory setup, they have been shown to markedly enhance placental imaging. In gynecology, imaging of the uterine cavity and Fallopian tubes is greatly improved. A potential area where ultrasound contrast may find a role is gynecological oncology. Vascularity is increased in many tumors, but usually vessel diameter is small and velocity low. One can therefore expect future use of the ultrasound contrast agents in ovarian or other gynecological neoplasms.