Contrast-Enhanced Sonographic Appearance Of Ovarian Tumors And The Correlation With Microvessel Density

objectivesTo investigate the enhancement appearance of contrast-enhanced ultrasound according to ovarian benign tumors and malignant tumors ; To investigate the types of curve and parameters of time-intensity curve (TIC) of contrast-enhanced ultrasound (CEUS) used in differentiating ovarian malignant tumors from benign tumors. To investigate the correlation between the parameters of time-intensity curve and microvessel density (MVD).MethodsBetween January 2007 to December 2007, an analysis was performed of 26 women with suspected complex adnexal masses at ShengJing Hospital, China Medical University. The patients underwent contrast- enhanced ultrasound (CEUS) examination during the week prior to surgery. During the study period, 10 women with normal adnexa agreed to undergo contrast- enhanced ultrasound (CEUS) examination and were selected as controls. All the tumors were classified into malignant group including 10 cancers and benign group including 16 benign tumors according to histological results and follow-up US examinations.The equipment used in the study was American LOGIQ9 GE (probe frequency 2-4 MHZ). The contrast agent (SonoVue, Italy Bracco company) consists of sulfur hexafluoride(SF6) surrounded by phospholipids. SonoVue was injected as a bolus of 1.5ml by cubital vein. The tumor was scanned with a conventional sonography to select an appropriate section, mechanical index is low (0.08-0.10). Code PI mode was chosen to perform the contrast-enhanced ultrasound examination. The entire scanning process was recorded for the following analysis. Then started TIC soft to analysis all images. The parameters of time-intensity curve: the base time, peak time, basic intensity, peak intensity, enhancement rate, declined rate. The tumor slices were stained by CD34 with immunohistochemical method (SP method).All statistical analysis was performed by using the SPSS 13.0 statistical package. A P-value <0.05 was considered to be statistically significant.Results1,The enhancement appearance of contrast-enhanced ultrasound for malignant tumors and benign tumors is different, the benign ovarian tumors appear the enhancement of contrast agent regularly from periphery into centre and show normal vessel calibers, while malignant tumors appear the enhancement irregularly on vascular as centre and show heterogeneous features including bulky, tortuous, irregular caliber vascular pattern which look like crab feet or branches.2,The curve appeared slow-up and slow-down type in the benign group and the normal group, but quick-up and slow-down type in the malignant group.3,The peak time was shorter in malignant group than that of benign group, the peak time was shorter in benign group than that of normal group, and have statistical significance among the three groups(P<0.05).The peak intensity and enhancement rate in malignant group were significantly higher than that in the benign group(p<0.05),the peak intensity and enhancement rate in the benign group was significantly higher than that in the normal group(P<0.05). the basic time, the basic intensity and declined rate have no significance among malignant group, benign group and normal group. As the ROC curve forecasting ovarian malignant tumors, the area under the curve of the peak intensity, intensity velocity and the peak time were 0.869, 0.858, 0.784 respectively.4,The MVD of malignant group was high than that of benign group. The difference between them was significant (P<0.05) .5,The peak time and the peak intensity of time-intensity curve were correlated with MVD, the correlation coefficients were 0.757 and -0.710 respectively(P<0.05). There was no relationship between basic time, basic intensity and enhancement rate, delined rate and MVD(P>0.05). Conclusions1,The enhanced appearance of contrast-enhanced ultrasound for malignant tumors and benign tumors is different, it is helpful in differentiating ovarian malignant tumors from benign tumors and in finding ovarian cancer of the earlier period.2,The type of time-intensity curve and the peak time, the peak intensity and intensity velocity of contrast-enhanced ultrasound have significant difference between ovarian malignant group and benign group. It is helpful for providing more objective information in differentiating ovarian malignant from benign tumors.3,The peak time and the peak intensity of CEUS time-intensity curve of ovarian tumors were correlated to MVD, the parameters of CEUS time-intensity curve obtained before operation can evaluate angiogenesis of tumors.