Quantification Of Ovarian Tumor Vascularity By 3D Power Doppler Ultrasonography

PrefaceMalignant tumors are highly dependent on vascularization for their growth and spread. The intratumoral blood flow of benign ovarian masses is different from the malignant ovarian masses. Three - dimensional (3 D) power Doppler is a non - invasive technology that evaluates the blood flow of pelvic organs. The latest technical achievement is three - dimensional imaging combined with power Doppler. 3 D power Doppler can improve visualization of the internal architecture of vessels and improve the accuracy in differentiation between benign and malignant ovarian masses. It also provides the possibility to quantify the power Doppler signal in the whole target organ. To date, cervical cancer, ovarian, ovarian tumor vascularity have been assessed quantitatively using 3D power Doppler ul-trasonography.This study aimed to compare the differentiation of the quantified indices between benign and malignant ovarian masses using 3D power Doppler ultrasonog-raphy.Materials and MethodsFrom May 2004 to Spring 2005, an analysis was performed of 44 women with suspected complex adnexal masses at Second Hospital, China Medical University. All the patients underwent 3D power Doppler examination during the week prior to surgery. All the patients of malignant ovarian masses were stagedclinically according to the staging system of the International Federation of Gyne-cology and Obstetrics ( FIGO).During the study period, 20 women with normal adnexal agreed to undergo 3D power Doppler examinations and were selected as controls. In order to escape from false - positives caused by increased vascularity of the corpus luteum and/or follicular structure, all the examinations were performed during the early proliferative phase of the menstrual cycle.The equipment used in the study was Medison Accuvix XQ with 5-8 MHz transvaginal transducers.Each patient underwent systematic gray - scale three - dimensional examination of uterus and ovaries with special emphasis on the adnexal masses and the power Doppler mode was switched on. The Virtual Organ Computer - aided A-naLysis ( VOCAL) program then automatically calculated grey - scale and color values for the ovarian masses volume. According to these values the indices were calculated; vascularization index ( VI) , flow index (FI) , vascularization flow index (VFI). According to the distribution of the vessels, the vascular distribution in adnexal masses was classified as follows; pattern I , no detectable vessels in masses; pattern II , sparse detectable vessels in masses; pattern III, a-bundant detectable vessels in masses.The statistical data were analyzed using the Statistical Package for the Social Sciences (SPSS). Data are represented as mean SEM. Comparisons were performed by One - Way ANOVA and Student' s t - test. P value < 0. 05 was considered to be significant.ResultsThe values of detectable blood flow were 15/23 (65.2% ) in benign ovarian masses and 21/21 (100% ) in malignant ovarian masses.(1) Significant differences between means for benign and malignant ovarian masses or between means for normal controls and malignant ovarian masses were found for following parameters: VI, FI, VFI. The quantified blood flow indices in benign ovarian masses were significantly lower than in malignant ovarian mas-ses. A comparison of indices between normal controls and benign ovarian masses showed that there were significant differences only in VI, but insignificant differences in FI, VFI.(2) Statistically significant differences existed in VI, FI, VFI between pattern II and pattern M. The quantified blood flow indices in pattern II were significantly lower than in pattern M.(3) Significant differences between means for normal controls and FIGO I / II , III/ IV were found for following parameters: VI, FI, VFI. But therewere no significant differences in VI, FI, VFI values between FIGO I /II and FIGO W/W .Discussion1. The value of ovarian malignant tumor diagnosis using 3D power Doppler.It was reported that the benign adnexal masses were mostly vascularized peripherally, while in malignant tumors centrally located vascularization was most frequent. According to the characteristic of the distributions of blood flow, it could improve the diagnostic accuracy of differentiation benign from malignant adnexal masses.RI and the vascular distribution of power Doppler signal were the most important indices in differentiation benign from malignant adnexal masses. Recently , the newest technological advance in evaluation of the vascular flow and flow pattern was the ability to evaluate using 3D power Doppler from multipla-nar, displaying the changes of intratumoral blood architecture and distribution. 3D and 3D power Doppler could improve the diagnostic accuracy of malignant o-varian tumor.2. The value of quantified indices using 3D power Doppler sonography. The three indices were calculated by the three - dimensional power Dopplerhistogram analysis. VI measures the ratio of color voxels to all voxels in ROI, and represents the density of vessels in the tissue. FI, the mean value of the color voxels, represents the average intensity of flow. VFI is the mean color value in all the voxels in the ROI, and is a feature of both vascularization and flow.Our study results demonstrated the quantified indices VI, FI, VFI between benign and malignant ovarian masses were statistically significant. All the quantified blood flow indices in benign ovarian masses were significantly lower than in malignant ovarian masses. The number of neovascularization and the blood cell in malignant ovarian masses were significantly higher than in benign ovarian masses. A comparison of indices between benign ovarian masses and normal controls showed that there was significantly different only in VI. The tumor cells needed more vessels that could provide oxygen and nourishment. VI represents the density of vessels in the tissue. The numbers of the detected vessels in benign ovarian masses were more than these in the normal controls. But the overlap of blood flow indices between benign and malignant ovarian masses could affect the accuracy in differentiation of ovarian masses.3. The correlation between the vascular pattern and the quantified blood flow indicesIn our study, the numbers of pattern I , II in benign ovarian masses were 19/23 (82.6% ) , but the malignant ovarian masses had no pattern I . The sensitivity and specificity respectively of pattern HI as a the diagnostic criterion were 69.2% , 61.3%. Our study results demonstrated that the quantified indices VI, FI, VFI between pattern II and pattern III were statistically significant. The blood flow of pattern II were far lower than pattern III. The values of three indices would reflect degree of blood flow in ovarian masses.4. The correlation between FIGO stage and the quantified blood flow indices.Significant differences between means for normal controls and FIGO I / II , HI/IV were found for following parameters: VI, FI and VFI. The role of 3D power Doppler ultrasound in preoperative assessment of ovarian malignancy stressed the importance of this imaging modality in reliable and accurate detection of early stage malignant ovarian masses. The three indices could reflect the abnormal changes in vasculature of early stage malignant ovarian masses. The quantified indices using 3D power Doppler should help early diagnosing the malignant ovarian masses.There was no correlation between FIGO stage and the quantified blood flow...