Does three-dimensional power Doppler ultrasound help in discrimination between benign and malignant ovarian masses?

Ultrasound evaluation of ovarian masses and assessment of the extension of ovarian malignancy

The current review sums up the literature on the diagnostic performance of models to predict malignancy in adnexal masses and the ability of ultrasound to make a specific diagnosis in adnexal masses. A summary of the role of ultrasound in assessing the extension of malignant ovarian disease is also provided.

Diagnostic value of endometrial volume and flow parameters under 3D ultrasound acquisition in combination with serum CA125 in endometrial lesions

OBJECTIVE

This study aims to discuss the differential diagnosis value of endometrial volume and flow parameters in combination with serum carbohydrate antigen 125 (CA125) in endometrial benign and malignant lesions.

MATERIALS AND METHODS

The data of 250 patients with endometrial lesions were retrospectively analyzed. Carbohydrate antigen 125 (CA125) was determined before the operation. The morphology, hemodynamics, volume and flow parameters of the endometrium were measured by transvaginal three-dimensional-power Doppler angiography (3D-PDA). The endometrial volume (EV), 3D-PDA vascular index (VI), flow index (FI) and vascularization flow index (VFI) were calculated using the virtual organ computer-aided analysis software (VOCAL).

RESULTS

According to the pathological results, 202 patients (80.8%) had benign endometrial lesions and 48 patients (19.2%) had endometrial cancer (EC). The endometrium of EC patients was thicker (15.64 ± 7.26 mm vs. 9.24 ± 5.06 mm, P < 0.001), the endometrial volume was larger (9.23 ± 4.08 ml vs. 2.26 ± 3.42 ml, P < 0.001), and the flow parameters VI, FI and VFI were higher, when compared to those of benign lesions (P < 0.001). The area under the receiver operating characteristic curve (AUROCC) of VI receptors was 0.86, while the AUC of endometrial thickness (ET) was only 0.66. Therefore, the best variable for distinguishing benign and malignant endometrial lesions was VI. The level of CA125 in the EC group significantly increased (40.57 ± 17.45 vs. 17.87 ± 7.64, P < 0.001), and the level of CA125 increased (P < 0.05) with the increase in clinical grade, degree of tumor differentiation, and pelvic lymph node metastasis (P < 0.05). However, the difference in myometrial invasion was not statistically significant (P > 0.05).

CONCLUSION

Transvaginal 3D-PDA can clearly show the morphological and hemodynamic characteristics of endometrial lesions, and assist in the detection of EC in combination with serum CA125. This may have important clinical application value.

4D Doppler Ultrasound in High Grade Serous Ovarian Cancer Vascularity Evaluation-Preliminary Study

The aim of the study was to evaluate the usefulness of 4D Power Doppler tissue evaluation to discriminate between normal ovaries and ovarian cancer tumors. This was a prospective observational study. Twenty-three cases of surgically confirmed ovarian High Grade Serous Carcinoma (HGSC) were analyzed. The control group consisted of 23 healthy patients, each matching their study-group counterpart age wise (±3 years) and according to their menopausal status. Transvaginal Doppler 4D ultrasound scans were done on every patient and analyzed with 3D/4D software. Two 4D indices-volumetric Systolic/Diastolic Index (vS/D) and volumetric Pulsatility Index (vPI)-were calculated. To keep results standardized and due to technical limitations, virtual 1cc spherical tissue samples taken from the part with highest vascularization as detected by bi-directional Power Doppler were analyzed for both groups of ovaries. Values of volumetric S/D indices and volumetric PI indices were statistically lower in ovarian malignant tumors compared to normal ovaries: 1.096 vs. 1.794 and 0.092 vs. 0.558, respectively (p < 0.001). The 4D bi-directional Power Doppler vascular indices were statistically different between malignant tumors and normal ovaries. These findings could support the rationale for future studies for assessing this technology to discriminate between malignant and benign tumors.

Vessel morphology depicted by three-dimensional power Doppler ultrasound as second-stage test in adnexal tumors that are difficult to classify: prospective diagnostic accuracy study

OBJECTIVES

To assess whether vessel morphology depicted by three-dimensional (3D) power Doppler ultrasound improves discrimination between benignity and malignancy if used as a second-stage test in adnexal masses that are difficult to classify.

METHODS

This was a prospective observational international multicenter diagnostic accuracy study. Consecutive patients with an adnexal mass underwent standardized transvaginal two-dimensional (2D) grayscale and color or power Doppler and 3D power Doppler ultrasound examination by an experienced examiner, and those with a 'difficult' tumor were included in the current analysis. A difficult tumor was defined as one in which the International Ovarian Tumor Analysis (IOTA) logistic regression model-1 (LR-1) yielded an ambiguous result (risk of malignancy, 8.3% to 25.5%), or as one in which the ultrasound examiner was uncertain regarding classification as benign or malignant when using subjective assessment. Even when the ultrasound examiner was uncertain, he/she was obliged to classify the tumor as most probably benign or most probably malignant. For each difficult tumor, one researcher created a 360° rotating 3D power Doppler image of the vessel tree in the whole tumor and another of the vessel tree in a 5-cm³ spherical volume selected from the most vascularized part of the tumor. Two other researchers, blinded to the patient's history, 2D ultrasound findings and histological diagnosis, independently described the vessel tree using predetermined vessel features. Their agreed classification was used. The reference standard was the histological diagnosis of the mass. The sensitivity of each test for discriminating between benign and malignant difficult tumors was plotted against 1 - specificity on a receiver-operating-characteristics diagram, and the test with the point furthest from the reference line was considered to have the best diagnostic ability.

RESULTS

Of 2403 women with an adnexal mass, 376 (16%) had a difficult mass. Ultrasound volumes were available for 138 of these cases. In 79/138 masses, the ultrasound examiner was uncertain about the diagnosis based on subjective assessment, in 87/138, IOTA LR-1 yielded an ambiguous result and, in 28/138, both methods gave an uncertain result. Of the masses, 38/138 (28%) were malignant. Among tumors that were difficult to classify as benign or malignant by subjective assessment, the vessel feature 'densely packed vessels' had the best discriminative ability (sensitivity 67% (18/27), specificity 83% (43/52)) and was slightly superior to subjective assessment (sensitivity 74% (20/27), specificity 60% (31/52)). In tumors in which IOTA LR-1 yielded an ambiguous result, subjective assessment (sensitivity 82% (14/17), specificity 79% (55/70)) was superior to the best vascular feature, i.e. changes in the diameter of vessels in the whole tumor volume (sensitivity 71% (12/17), specificity 69% (48/70)).

CONCLUSION

Vessel morphology depicted by 3D power Doppler ultrasound may slightly improve discrimination between benign and malignant adnexal tumors that are difficult to classify by subjective ultrasound assessment. For tumors in which the IOTA LR-1 model yields an ambiguous result, subjective assessment is superior to vessel morphology as a second-stage test. © 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Multiparametric Ultrasound Examination in Tumor-Like Formations of the Ovaries

Properly diagnosed tumor-like formations of the ovaries facilitate the correct selection of patients who may not require surgery, or choose surgery with minimal access if such intervention is required. Subjective assessment of the features of tumor-like formations with the help of ultrasound diagnostics, including compression elastography, proved to be highly effective in the differential diagnosis of bulky ovarian formations. All tumor-like formations have their sonographic features that allow making a reliable diagnosis of a particular formation. The article reveals data on the diagnostic significance of multiparametric ultrasound imaging in the detection of ovarian tumor-like formations. A detailed sonographic picture of tumor-like formations in B-mode, color, and pulse Doppler mode and compression sonoelastography mode was analyzed. This examination was especially relevant for women of reproductive age, as it depended on the further tactics of treatment of each patient. For all types of tumor-like formations ovaries, a qualitative feature was determined - elastotype on the Ueno scale and the index of stiffness (Strain Ratio) - a quantitative indicator. Follicular cysts, endometrioid and periovarian cysts were found to belong to the 0 elastotype. Cysts of the corpus luteum belonged to the II elastotype on the Ueno scale. The lowest values of the stiffness index were seen in follicular and periovarian cysts, and the highest value was observed in endometrioid cysts. Our results have shown that ultrasound examination of ovarian tumors is an accurate and highly informative method.

Role of Combining Colour Doppler and Grey Scale Ultrasound in Differentiating Benign from Malignant Ovarian Masses

The aim of this study was to evaluate ovarian masses with conventional grey scale ultrasonography and colour Doppler flow imaging and to assess the diagnostic reliability of these methods in differentiating benign and malignant ovarian masses.

We assessed 56 patients with an ovarian mass. Morphological characterisation of the mass was performed utilising the Sassone score. Colour Doppler parameters were recorded for each patient, and the Caruso vascular score was also applied. The results were compared with surgical/pathological and/or follow-up scans.

Using the Sassone score, overall reliability in differentiating ovarian masses had a sensitivity of 89.5% and a specificity of 78.4%. Using the Caruso score alone, we found a sensitivity of 89.5% and a specificity of 86.5%. Using the Sassone and Caruso scores together, we found a sensitivity of 94.7% and a specificity of 89.1%.

Combining both morphological and colour Doppler scores in the evaluation of ovarian masses obtained higher specificity, sensitivity, and accuracy than was obtained using a single score only.

Reliability of preoperative evaluation of postmenopausal ovarian tumors

Background

Preoperative evaluation of ovarian tumors is challenging. This study was undertaken to evaluate the performance of conventional two-dimensional (2D) ultrasound and CA125 in predicting malignant or benign nature of pelvic masses, and to investigate if three-dimensional power Doppler (3DPD) ultrasound provides any added value. Ninety-six postmenopausal and four perimenopausal women with supposed ovarian tumors were examined by standardized 2D and 3DPD ultrasounds preoperatively. The tumors were evaluated using the risk of malignancy index (RMI), International Ovarian Tumors Analysis (IOTA) group simple rules, expert opinion, IOTA logistic regression model 2 (LR2) and 3D vascular indices, and were postoperatively compared to histopathological results.

Results

Ninety-eight tumors turned out to be ovarian in origin. Of these, 66 were benign and 32 malignant. RMI (cut-off value 200), simple rules, expert opinion and LR2 (cut-off value 25) were used to predict malignant nature of the tumors and had sensitivities of 71.9, 90.6, 87.5 and 90.6%, and specificities of 80.3, 84.6, 92.4 and 77.3%, respectively. When the 3D vascularization flow index (VFI) was added to RMI and LR2, the accuracy of the test improved from 77.6 to 81.4% and from 81.6 to 86.5%, respectively, at the expense of sensitivity, while VFI gave no added benefit for simple rules and expert opinion. Agreement between two examiners using expert opinion was good (Cohen’s kappa = 0.89).

Conclusions

The subjective opinion of an expert seems to be the most reliable method in assessing ovarian tumors, and the 3DPD indices seem to provide no significant added value.

Influence of Pulse Repetition Frequency on 3-D Power Doppler Quantification

Three-dimensional power Doppler quantification has limited application because of its high dependency on attenuation. The purpose of the study described here was to assess if different degrees of attenuation, depending on pulse repetition frequency (PRF) adjustment, alter 3-D power Doppler quantification in a region of 100% moving blood when using vascularization index, flow index and vascularization flow index (VFI). A cubic-shaped gelatin phantom with a 1.8-mm-internal-diameter silicon tube was used. The tube, placed at 45° to the phantom's surface, was filled with blood-mimicking fluid with as constant maximum velocity of 30 cm/s. Two different attenuation blocks (low and high attenuation) were alternatively placed between the phantom and the transvaginal transducer. One single observer acquired 10 data sets for each PRF level from 0.3 to 7.5 kHz, using the high- and low-attenuation blocks, for a total of 200 3-D power Doppler data sets. We assessed VFI from 1.5-mm-diameter spherical samples, virtually placed inside the tube, always at the same position. No difference was noted between high- and low-attenuation VFI values when using a PRF of 0.3 kHz. As PRF increased, it was observed that VFI quantification progressively differed between low and high attenuation. Also, a slope on VFI values for both high- and low-attenuation models could be observed when increasing PRF, particularly above 4.0 kHz. We concluded that PRF adjustment is very relevant when using VFI to quantify 3-D power Doppler signal.

Usefulness of transabdominal real-time sonoelastography in the evaluation of ovarian lesions: preliminary results

OBJECTIVE

We aim to evaluate and describe the tissue elasticity characteristics of various ovarian lesions with sonoelastography.

METHODS

35 patients (age range 16-85 years; mean age 40.8 years) underwent sonoelastography and later MRI. Histopathological confirmation of all lesions was carried out, except eight of endometriomas and six of septated cysts which were confirmed on MRI and follow-up ultrasonography. Strain ratios and elastogram patterns were recorded. Lesions were classified into three groups (Group 1: cystic lesions, Group 2: benign tumours and Group 3: malignant lesions) and findings were compared between groups for both observers. Interobserver agreement was analyzed. Optimal cut-off values for strain ratios were achieved with receiver operating characteristic curve analysis.

RESULTS

Ovarian endometriomas and complex cystic lesions were observed hard on elastograms with high strain ratios, and malignant lesions were observed mostly soft with very small strain ratios. Benign tumours had average tissue stiffness, observed harder than the malignant lesions, and strain ratios ranged from 4 to 14. The differences in patterns and strain ratios between groups were statistically significant (p < 0.05 for both observers).

CONCLUSION

Our study revealed that malignant ovarian lesions have softer tissue property than benign lesions and cystic lesions in terms of elastogram patterns and strain ratios.

ADVANCES IN KNOWLEDGE

Most ovarian lesions contain solid and cystic parts which make the malignant and benign lesions look similar on imaging modalities. Using real-time sonoelastography as an adjunct to other imaging modalities may improve the differentiation of malignant ovarian lesions from benign lesions.

Past, present and future ultrasonographic techniques for analyzing ovarian masses

Ultrasonography is today the method of choice for distinguishing between benign and malignant adnexal pathologies. Using pattern recognition several types of tumors can be recognized according to their characteristic appearance on gray-scale imaging. Color Doppler imaging should be used only to perform a semiquantitative color score or evaluate the flow location. International Ovarian Tumor Analysis group had standardized definitions characterizing adnexal masses and suggested the use of 'simple rules' in premenopausal women. Recently, the use of 3D vascular indices has been proposed but its potential use in clinical practice is debated. Also computerized aided diagnosis algorithms showed encouraging results to be confirmed in the future.

Limitations of three-dimensional power Doppler angiography in preoperative evaluation of ovarian tumors

Background

This study describes the accuracy of three-dimensional power Doppler (3D-PD) angiography as secondary method for differential diagnosis of ovarian tumors.

Method

Seventy-five women scheduled for surgical removal of adnexal masses were assessed by transvaginal ultrasound. Ovarian tumors were classified by IOTA simple rules and two three-dimensional blocks were recorded. In a second step analyses, a 4 cm³ spherical sample was obtained from the highest vascularized solid area of each stored block. Vascularization index (VI), flow index (FI) and vascularization-flow index (VFI) were calculated. The repeatability was assessed by concordance correlation coefficient (CCC) and limits of agreement (LoA), and diagnostic accuracy by area under ROC curve.

Results

IOTA simple rules classified 26 cases as benign, nine as inconclusive and 40 as malignant. There were eight false positive and no false negative. Among the masses classified as inconclusive or malignant by IOTA simple rules, the CCCs were 0.91 for VI, 0.70 for FI, and 0.86 for VFI. The areas under ROC curve were 0.82 for VI, 0.67 for FI and 0.81 for VFI.

Conclusions

3D-PD angiography presented considerable intraobserver variability and low accuracy for identifying false positive results of IOTA simple rules.

Performance of three-dimensional power Doppler angiography as third-step assessment in differential diagnosis of adnexal masses

OBJECTIVE

To evaluate the contribution of three-dimensional (3D) power Doppler angiography (3D-PDA) to the differential diagnosis of adnexal masses.

METHODS

This was a prospective study in women diagnosed with a persistent adnexal mass and subsequently scheduled for surgery in a tertiary university hospital. All women were evaluated by transvaginal/transrectal ultrasound according to a predetermined three-step protocol, with transabdominal ultrasound being performed in some cases. First, morphological evaluation of the mass was performed using gray-scale 'pattern recognition' (first step). Lesions diagnosed as having a benign pattern were considered as being at low risk of malignancy whereas tumors with solid components, ascites and/or signs of carcinomatosis were considered as being at high risk of malignancy. In both cases no further test was performed and a decision regarding clinical management, either for follow-up or surgery, was taken. Tumors with solid components but without signs of ascites or carcinomatosis were considered as being at intermediate risk of malignancy. These lesions were assessed by two-dimensional (2D) PDA to evaluate tumor vascularity (color score) (second step). Solid tumors with a color score of 1 or 2 were considered as benign and no further test was performed, while tumors with a color score of 2, 3 or 4 within solid components or a color score of 3 or 4 in the case of a solid tumor were considered as malignant. The latter group underwent 3D-PDA assessment (third step). Vascularization index (VI) was calculated in a 1-mL sphere of the most vascularized area of the tumor. When a VI ≥ 24.015% was found, the tumor was considered as malignant. All masses were removed surgically and definitive histological diagnosis was used as the gold standard. Sensitivity and specificity for each strategy were calculated and compared. In the case of bilateral tumors, only the more suspicious one was used for analysis.

RESULTS

A total of 367 adnexal masses diagnosed in 367 women (mean age, 46.5 (range, 18-80) years) were evaluated during the study period. Of these, 86 masses were malignant and 281 were benign. The sensitivity and specificity for each assessment strategy were as follows: one-step, 97.7% and 78.6%; two-step, 94.2% and 97.9% (P < 0.001 for specificity when compared with that of one-step); three-step, 90.7% and 98.9% (not statistically significant when compared with that of two-step).

CONCLUSIONS

The addition of 2D-PDA in the differential diagnosis of an adnexal mass significantly increases specificity while sensitivity remains high; however performing subsequent 3D-PDA does not provide additional information or further improve diagnostic performance subsequent to 2D-PDA.

Usefulness of diagnostic indices comprising clinical, sonographic, and biomarker data for discriminating benign from malignant ovarian masses

The objective of this study was to review the accuracy of indices combining several diagnostic variables, in comparison to other models, sonography alone, and biomarker assays, for predicting benign or malignant ovarian lesions. Different single modalities were reviewed. The most useful complex models were International Ovarian Tumor Analysis (IOTA) sonographic logistic regression model 2 (area under the curve, 0.949), risk of malignancy index-cancer antigen 125-human epididymis protein 4 (0.950), risk of malignancy algorithm (0.953), pelvic mass score (0.960), non-IOTA logistic regression model (0.970), and histoscanning score logistic regression model (0.970). None of the indices was superior to an expert subjective sonographic assessment (0.968). For women with adnexal tumors, indices with high accuracy are available that are applicable in clinical practice and comparable to an expert subjective sonographic assessment for discriminating benign from malignant masses.

GyneScan: an improved online paradigm for screening of ovarian cancer via tissue characterization

Ovarian cancer is the fifth highest cause of cancer in women and the leading cause of death from gynecological cancers. Accurate diagnosis of ovarian cancer from acquired images is dependent on the expertise and experience of ultrasonographers or physicians, and is therefore, associated with inter observer variabilities. Computer Aided Diagnostic (CAD) techniques use a number of different data mining techniques to automatically predict the presence or absence of cancer, and therefore, are more reliable and accurate. A review of published literature in the field of CAD based ovarian cancer detection indicates that many studies use ultrasound images as the base for analysis. The key objective of this work is to propose an effective adjunct CAD technique called GyneScan for ovarian tumor detection in ultrasound images. In our proposed data mining framework, we extract several texture features based on first order statistics, Gray Level Co-occurrence Matrix and run length matrix. The significant features selected using t-test are then used to train and test several supervised learning based classifiers such as Probabilistic Neural Networks (PNN), Support Vector Machine (SVM), Decision Tree (DT), k-Nearest Neighbor (KNN), and Naive Bayes (NB). We evaluated the developed framework using 1300 benign and 1300 malignant images. Using 11 significant features in KNN/PNN classifiers, we were able to achieve 100% classification accuracy, sensitivity, specificity, and positive predictive value in detecting ovarian tumor. Even though more validation using larger databases would better establish the robustness of our technique, the preliminary results are promising. This technique could be used as a reliable adjunct method to existing imaging modalities to provide a more confident second opinion on the presence/absence of ovarian tumor.

The contribution of qualitative CEUS to the determination of malignancy in adnexal masses, indeterminate on conventional US - a multicenter study

The aim of this study is to evaluate the efficacy of qualitative analysis of contrast-enhanced ultrasound (CEUS) in discrimination of adnexal masses which were undetermined by conventional ultrasound (US). A total of 120 patients underwent transabdominal CEUS. The initial enhancement time and intensity compared with the uterine myometrium, contrast agent distribution patterns and dynamic changes of enhancement were assessed. The sensitivity (Sen), specificity (Spe), positive predictive value (PPV), negative predictive value (NPV), accuracy (ACC) and Youden’s index were calculated for contrast variables. The gold standard was the histological diagnosis. There were 48 malignant tumors and 72 benign tumors. The enhancement features of malignant masses were different from benign ones. Earlier or simultaneous enhancement with inhomogeneous enhancement yielded the highest capability in differential diagnosis, and Sen, Spe, PPV, NPV, ACC, Youden’s index was 89.6%, 97.2%, 93.2%, 95.6%, 93.3%, and 0.88, respectively. The qualitative evaluation of CEUS is useful in the differential diagnosis of adnexal masses where conventional US is indeterminate.

Presurgical diagnosis of adnexal tumours using mathematical models and scoring systems: a systematic review and meta-analysis

BACKGROUND Characterizing ovarian pathology is fundamental to optimizing management in both pre- and post-menopausal women. Inappropriate referral to oncology services can lead to unnecessary surgery or overly radical interventions compromising fertility in young women, whilst the consequences of failing to recognize cancer significantly impact on prognosis. By reflecting on recent developments of new diagnostic tests for preoperative identification of malignant disease in women with adnexal masses, we aimed to update a previous systematic review and meta-analysis. METHODS An extended search was performed in MEDLINE (PubMed) and EMBASE (OvidSp) from March 2008 to October 2013. Eligible studies provided information on diagnostic test performance of models, designed to predict ovarian cancer in a preoperative setting, that contained at least two variables. Study selection and extraction of study characteristics, types of bias, and test performance was performed independently by two reviewers. Quality was assessed using a modified version of the QUADAS assessment tool. A bivariate hierarchical random effects model was used to produce summary estimates of sensitivity and specificity with 95% confidence intervals or plot summary ROC curves for all models considered. RESULTS Our extended search identified a total of 1542 new primary articles. In total, 195 studies were eligible for qualitative data synthesis, and 96 validation studies reporting on 19 different prediction models met the predefined criteria for quantitative data synthesis. These models were tested on 26 438 adnexal masses, including 7199 (27%) malignant and 19 239 (73%) benign masses. The Risk of Malignancy Index (RMI) was the most frequently validated model. The logistic regression model LR2 with a risk cut-off of 10% and Simple Rules (SR), both developed by the International Ovarian Tumor Analysis (IOTA) study, performed better than all other included models with a pooled sensitivity and specificity, respectively, of 0.92 [95% CI 0.88-0.95] and 0.83 [95% CI 0.77-0.88] for LR2 and 0.93 [95% CI 0.89-0.95] and 0.81 [95% CI 0.76-0.85] for SR. A meta-analysis of centre-specific results stratified for menopausal status of two multicentre cohorts comparing LR2, SR and RMI-1 (using a cut-off of 200) showed a pooled sensitivity and specificity in premenopausal women for LR2 of 0.85 [95% CI 0.75-0.91] and 0.91 [95% CI 0.83-0.96] compared with 0.93 [95% CI 0.84-0.97] and 0.83 [95% CI 0.73-0.90] for SR and 0.44 [95% CI 0.28-0.62] and 0.95 [95% CI 0.90-0.97] for RMI-1. In post-menopausal women, sensitivity and specificity of LR2, SR and RMI-1 were 0.94 [95% CI 0.89-0.97] and 0.70 [95% CI 0.62-0.77], 0.93 [95% CI 0.88-0.96] and 0.76 [95% CI 0.69-0.82], and 0.79 [95% CI 0.72-0.85] and 0.90 [95% CI 0.84-0.94], respectively. CONCLUSIONS An evidence-based approach to the preoperative characterization of any adnexal mass should incorporate the use of IOTA Simple Rules or the LR2 model, particularly for women of reproductive age.

[Sonographic diagnosis of presumed benign ovarian tumors]

To discriminate ovarian lesions is of particular importance in gynecological practice. Two main problems need answers: discrimination of benign and malignant adnexal masses and choice of the appropriate surgical treatment if necessary. Nearly 2% of the adnexal masses are ovarian carcinomas or borderline tumors. It is now, well established that ultrasonography is the gold standard for ovarian cyst diagnosis. The purpose of this data was to review the literature and to establish, with the evidence base medicine model, which parameters and existing diagnostic models using ultrasound and Doppler perform best in the evaluation of adnexal masses. Transvaginal sonography has demonstrated considerable advantage over conventional transabdominal sonography. However, transparietal sonography is still useful in large tumors. Definition of the nomenclature and classification was done and should be used. Unilocular ovarian cyst characterization seems easy using sonography and Doppler. In front of complication, discrimination of such functional cyst may be difficult but spontaneous regression confirms usually the expectative management. Dermoid cysts and endometriomas seem to be easier to discriminate from other adnexal masses. Ultrasound and morphologic parameters have a sensitivity of about 90% and a specificity of 80%; that makes this exam the gold standard for ovarian masses diagnosis. Only 50% of ovarian masses are characterized by sonography. Scoring systems help to differentiate benign from malignant masses (sensitivity of about 90%). Logistic regression and models are good methods especially for LR1 and 2 and RMI and may be useful for malignancy prediction but are difficult to use in current practice. Expert diagnosis is a subjective but most important performing parameter. Any suspicious ovarian mass or not easily diagnosed mass requires sonography by an expert, which can first use all the techniques and the different parameters to discriminate benign and malignant tumors. An explicit report will help the physician to define the right attitude for an appropriate management. Six to 16% of adnexial masses are complex or not classified and will result in MRI prescription or surgery.

Intra- and interobserver agreement when describing adnexal masses using the International Ovarian Tumor Analysis terms and definitions: a study on three-dimensional ultrasound volumes

OBJECTIVES

To estimate intraobserver repeatability and interobserver agreement in: (1) describing adnexal masses using the International Ovarian Tumor Analysis (IOTA) terms and definitions; (2) the risk of malignancy calculated using IOTA logistic regression model 1 (LR1) and model 2 (LR2); and (3) the diagnosis made on the basis of subjective assessment of ultrasound images.

METHODS

One-hundred and three adnexal masses were examined by transvaginal gray-scale and power Doppler ultrasound. Three-dimensional ultrasound volumes of the mass were saved. After 12-18 months the volumes were analyzed twice, 1-6 months apart, by each of two independent experienced sonologists who used the IOTA terms and definitions to describe the masses. The risk of malignancy was calculated using LR1 and LR2. The sonologists also classified the masses as benign or malignant using subjective assessment.

RESULTS

Eighty-four masses were benign, eight were borderline and 11 were invasively malignant. There was substantial variability within and between observers in the results of measurements included in LR1 and LR2 and some variability also when assessing categorical variables included in the models (agreement = 51-100% and kappa = 0.42-1.00). This resulted in substantial variability in the calculated risk of malignancy, the limits of agreement indicating that the calculated risk of malignancy could vary by a factor of 5-20 within and between observers. The reliability of the calculated risk of malignancy was moderate (LR1) or poor (LR2) when the calculated risk of malignancy was > 10% (intraclass correlation coefficients varied from 0.21 to 0.73). Interobserver agreement when classifying tumors as benign or malignant using the predetermined risk of malignancy cut-off of 10% was fair to good (agreement = 85% and kappa = 0.61 for LR1; agreement = 81% and kappa = 0.52 for LR2). Intra- and interobserver agreements for subjective assessment were 96%, 96% and 96% with kappa values of 0.89, 0.87 and 0.88, respectively.

CONCLUSIONS

Intra- and interobserver agreement in classifying tumors as benign or malignant using the risk of malignancy cut-off of 10% for LR1 and LR2 was fair or good, whilst the reproducibility of subjective assessment was excellent. The reliability of calculated risks > 10% was poor, and calculated risk > 10% cannot be used to discriminate between individuals at different risk. These results cannot be extrapolated to real-time ultrasound examinations.

Risk of malignancy in unilocular cysts: a study of 1148 adnexal masses classified as unilocular cysts at transvaginal ultrasound and review of the literature

OBJECTIVES

The aim of this study was to estimate the rate of malignancy in adnexal lesions described as unilocular cysts at transvaginal ultrasound examination and to investigate if there are differences in clinical and ultrasound characteristics between benign and malignant unilocular cysts.

METHODS

A total of 3511 patients with an adnexal mass underwent transvaginal ultrasound examination between 1999 and 2007. Sonologists used the International Ovarian Tumor Analysis terms and definitions to describe their ultrasound findings. Only masses operated on within 120  days after the ultrasound examination were included in the analysis and the histopathological diagnosis of the mass was used as the gold standard.

RESULTS

Of the 3511 masses, 1148 (33%) were classified as unilocular cysts on ultrasound. Of these, 11 (0.96% (95% CI, 0.48-1.71)) were malignant. The malignancy rate was lower in premenopausal than in postmenopausal women: 0.54% (5/931; 95% CI, 0.17-1.25) vs. 2.76% (6/217; 95% CI, 1.02-5.92); P = 0.009. More patients with malignant unilocular cysts had a personal history of breast cancer (18% vs. 2%; P = 0.02) or ovarian cancer (18% vs 0.6%; P = 0.003). Hemorrhagic cyst contents on ultrasound were more common in malignant than in benign unilocular cysts (18% vs. 2%; P = 0.03). In seven of the 11 malignancies judged to be unilocular cysts at scan, papillary projections or other solid components were seen at macroscopic inspection of the surgical specimen.

CONCLUSIONS

The malignancy rate in surgically removed adnexal lesions judged to be unilocular cysts at transvaginal scan is c 1%. Postmenopausal status, personal history of breast or ovarian cancer and hemorrhagic cyst contents on ultrasound increase the risk of malignancy. To avoid misclassifying adnexal lesions as unilocular cysts at scan, it is important to scrutinize unilocular cysts for the presence of solid components.

Does three-dimensional power Doppler ultrasound predict histopathological findings of uterine fibroids? A preliminary study

OBJECTIVES

To compare three-dimensional (3D) power Doppler sonographic characteristics of fibroids with histopathological parameters.

METHODS

We evaluated sonographically 73 fibroids before myomectomy or hysterectomy. For each, the total fibroid volume, a shell of 3 mm and a 1-cm(3) spherical sample from the most vascularized area on subjective assessment were captured. 3D power Doppler vascularization index (VI), flow index (FI) and vascularization flow index (VFI) were generated in the acquired volumes. The degree of cellularity, ischemic necrosis and fibrosclerosis, as well as CD31 and Ki-67 staining for vascular density and proliferation index, respectively, were estimated using the surgical sample. Pathological data were considered as dependent variables and ultrasound data as independent variables in multivariable logistic regression models including patients' characteristics.

RESULTS

A high histological 'cellular activity score', combining hypercellularity, a fibrosclerosis rate < 25% and positive Ki-67 staining, was statistically related in multivariate analyses to high 3D power Doppler VI in spherical samples (odds ratio (OR), 1.1 (95% CI, 1.0-1.3), P < 0.05) and VFI (OR, 1.3 (95% CI, 1.0-1.8), P < 0.05). Positive CD31 staining was statistically related to high 3D power Doppler VI in spherical samples (OR, 1.1 (95% CI, 1.0-1.3), P < 0.05). In contrast, ischemic necrosis was statistically related to low 3D power Doppler VI in the total volume (OR, 0.6 (95% CI, 0.4-1.0), P < 0.05) and VFI (OR, 0.4 (95% CI, 0.1-1.1), P < 0.05).

CONCLUSION

Vascular density, ischemic necrosis and histological cellular activity score are statistically significantly associated with some 3D power Doppler indices.

Evaluation of selected ultrasonographic parameters and marker levels in the preoperative differentiation of borderline ovarian tumors and ovarian cancers

Abstract

Objectives

In young patients with borderline tumors the fertility-sparing treatment is indicated, thus the preoperative investigation is important. The aim of this study was to perform a comparative assessment of sensitivity and specificity of selected ultrasonographic and clinical parameters for the diagnoses of borderline tumors and ovarian cancers.

Methods

We retrospectively analyzed 57 patients who underwent surgical treatment in the Maria Sklodowska-Curie Memorial Cancer Center from Jan 01, 2008 to Dec 31, 2009. Ovarian cancers were diagnosed in 41 patients, and borderline ovarian tumors in 16 patients. Statistical model was developed to determine independent predictive factors that would be useful in preoperative differentiation between both tumors. The model included the following factors: menopausal status, tumor morphology, wall thickness (including outgrowths), septal thickness, echogenicity, resistive index, serum CA-125 level, and free fluid in the peritoneal cavity.

Results

Based on the statistical model developed, independent predictive factors in the differentiation between ovarian cancers and borderline tumors included the menopausal status (P = 0.005), tumor echogenicity (P = 0.047) and the presence of free fluid in the Douglas pouch (P = 0.043). With the cutoff value of 13 (with scores below 13 indicating a borderline ovarian tumor, and scores of ≥13 indicating ovarian cancer), sensitivity was 90.2 % and specificity was 87 %.

Conclusions

Our proposed model of preoperative evaluation has a sensitivity of 90 % in the differentiation between ovarian cancers and borderline tumors. When combined with intraoperative findings, it allows optimal surgical therapeutic decisions to be made in patients with borderline ovarian tumors.

External validation of diagnostic models to estimate the risk of malignancy in adnexal masses

PURPOSE

To externally validate and compare the performance of previously published diagnostic models developed to predict malignancy in adnexal masses.

EXPERIMENTAL DESIGN

We externally validated the diagnostic performance of 11 models developed by the International Ovarian Tumor Analysis (IOTA) group and 12 other (non-IOTA) models on 997 prospectively collected patients. The non-IOTA models included the original risk of malignancy index (RMI), three modified versions of the RMI, six logistic regression models, and two artificial neural networks. The ability of the models to discriminate between benign and malignant adnexal masses was expressed as the area under the receiver operating characteristic curve (AUC), sensitivity, specificity, and likelihood ratios (LR(+), LR(-)).

RESULTS

Seven hundred and forty-two (74%) benign and 255 (26%) malignant masses were included. The IOTA models did better than the non-IOTA models (AUCs between 0.941 and 0.956 vs. 0.839 and 0.928). The difference in AUC between the best IOTA and the best non-IOTA model was 0.028 [95% confidence interval (CI), 0.011-0.044]. The AUC of the RMI was 0.911 (difference with the best IOTA model, 0.044; 95% CI, 0.024-0.064). The superior performance of the IOTA models was most pronounced in premenopausal patients but was also observed in postmenopausal patients. IOTA models were better able to detect stage I ovarian cancer.

CONCLUSION

External validation shows that the IOTA models outperform other models, including the current reference test RMI, for discriminating between benign and malignant adnexal masses.

The role of 3-dimensional power Doppler imaging in the assessment of ovarian teratoma in pregnancy: a case report

Background. Conventional sonography is the primary imaging tool for these pregnant women who present with an ovarian teratoma. In some cases, however, sonography diagnosis is difficult. We report a case of ovarian teratoma during pregnancy diagnosed by three-dimensional Power Doppler. The cyst was removed via laparotomy without fetal or maternal complications. Three-dimensional ultrasound with multiplanar view can better discriminate a benign ovarian teratoma from complex ovarian lesions or malignant tumors. Its role is significant especially during pregnancy as it may assist in determining which patients are requiring surgery and which are not. The results of three-dimensional sonography and magnetic resonance (MR) were equal but the role of MR imaging is limited in early pregnancy. Conclusions. Three-dimensional technique is a reliable diagnostic modality for preoperative assessment of an ovarian teratoma as it can be performed during the first trimester of pregnancy.

Comparison of reproducibility of manual and sphere contour methods for the measurement of vascularization in cervical carcinoma using the virtual organ computer-aided analysis II system

OBJECTIVE

The purpose of this study was to investigate the reproducibility of virtual organ computer-aided analysis II software (GE Healthcare, Milwaukee, WI), an integrated tool for 3-dimensional power Doppler angiography (3D-PDA), in measuring vascularization of cervical carcinoma under manual and automatic sphere contour modes.

METHODS

Eighty patients with cervical carcinoma were prospectively examined by observer 1 using transvaginal 3D-PDA. For each patient, measurements of the vascularization index, flow index, and vascularization-flow index were repeated twice under both manual and automatic sphere contour modes. Forty patients were randomly selected for another round of examination by observer 2 under the same setting. The reproducibility of vascularization measurements was assessed by the intraclass correlation coefficient (intra-CC), interclass correlation coefficient (inter-CC), and 95% limits of agreement (LOAs). Various analysis of variance models were used to estimate the contribution of each factor (observer, contour mode, and patient) to measurement variance.

RESULTS

For each observer, the manual contour mode outperformed the automatic sphere contour mode in reproducibility (intra-CC, 0.96 to 0.99 versus 0.77 to 0.94). In addition, repeated measurements of the manual mode had a smaller SD and a narrower LOA. For the manual contour mode, interobserver agreement was comparable with intraobserver agreement (inter-CC, 0.91 to 0.98, versus intra-CC, 0.96 to 0.99). However, the interobserver agreement was significantly smaller than the intraobserver agreement for the automatic sphere contour mode (inter-CC, 0.51 to 0.85, versus intra-CC, 0.77 to 0.94; P = .001).

CONCLUSIONS

The manual contour mode for 3D-PDA vascular measurements has better interobserver and intraobserver reproducibility than the automatic sphere contour mode. It is especially useful for measuring tumor tissues with irregular shapes and vascularity.

Peri- and post-menopausal incidental adnexal masses and the risk of sporadic ovarian malignancy: new insights and clinical management

Adnexal masses are common among peri- and post-menopausal women. Although ovarian cancer is a significant cause of mortality in menopausal women, large population-based studies demonstrate that the majority of adnexal masses are benign. Despite this, the appearance of an adnexal mass is a concern for the patient and an insight exercise for physicians. In most cases, an adnexal enlargement is an incidental finding, generally corresponding to a benign cyst and easily diagnosed by conventional ultrasound. Exceptionally an ovarian tumour may be malignant and should be treated as early as possible. When conventional ultrasound renders complex morphology other diagnostic tools must be used such as: colour Doppler and functional tumour vessel properties, serum CA 125 levels, nuclear magnetic resonance imaging and in some cases laparoscopy. Several new tumour markers are being studied for clinical application, although there are presently no clear recommendations. Adnexal masses with benign morphological and functional properties must be periodically monitored as an alternative to surgery since malignant transformation is exceptional.

Does sphere volume affect the performance of three-dimensional power Doppler virtual vascular sampling for predicting malignancy in vascularized solid or cystic-solid adnexal masses?

OBJECTIVE

To assess whether, when using spherical sampling with Virtual Organ Computer-Aided Analysis (VOCAL) for calculating three-dimensional (3D) power Doppler angiography (PDA) indices, the sphere volume affects performance in the prediction of malignancy in vascularized cystic-solid or solid adnexal masses.

METHODS

One hundred and thirty-eight women (mean +/- SD age, 51.8 +/- 14.1 years) diagnosed as having vascularized cystic-solid or solid adnexal masses on B-mode and two-dimensional (2D) power Doppler ultrasound were evaluated by 3D-PDA prior to surgery. Five women had bilateral masses, giving a total number of 143 masses analyzed. Vascularization was assessed using VOCAL software. 3D-PDA vascular indices (vascularization index (VI), flow index (FI) and vascularization flow index (VFI)) from the most vascularized area within papillary projections and solid areas were calculated automatically using spherical sampling. Five different volumes of sphere were used (1 cm(3), 2 cm(3), 3 cm(3), 4 cm(3) and 5 cm(3)) in each case. A definitive histological diagnosis was obtained in each case after surgical tumor removal.

RESULTS

One hundred and seventeen (82%) masses were malignant and 26 (18%) were benign. Morphological evaluation revealed 34 (24%) unilocular solid masses, 49 (34%) multilocular solid masses and 60 (42%) mostly solid masses. The 1-cm(3) sphere could be used in 100% of the cases, the 2-cm(3) sphere could be used in 98.2% of the cases and the 3-5-cm(3) spheres could be used in 97.2% of the cases. The median VI, FI and VFI for all sphere volumes were significantly higher in malignant compared with non-malignant tumors. Receiver-operating characteristics curve analysis showed that VI and VFI, independently of sphere volume, were better predictors of malignancy than was FI. The best cut-off values for the 3D-PDA indices differed depending on sphere volume. VI was significantly more specific than were VFI and FI.

CONCLUSIONS

Sphere volume does not affect the performance of 3D-PDA. We recommend the use of different cut-off values for 3D-PDA indices for discriminating between benign and malignant adnexal masses, depending on the sphere volume used. Use of VI is preferable due to its higher specificity.

Three-dimensional ultrasound imaging for discrimination between benign and malignant endometrium in women with postmenopausal bleeding and sonographic endometrial thickness of at least 4.5 mm

OBJECTIVES

To determine whether endometrial volume or power Doppler indices as measured by three-dimensional (3D) ultrasound imaging can discriminate between benign and malignant endometrium, to compare their diagnostic performance with that of endometrial thickness measurement using two-dimensional (2D) ultrasound examination, and to determine whether power Doppler indices add any diagnostic information to endometrial thickness or volume.

METHODS

Sixty-two patients with postmenopausal bleeding and endometrial thickness > or = 4.5 mm underwent transvaginal 2D gray-scale and 3D power Doppler ultrasound examination of the corpus uteri. The endometrial volume was calculated, along with the vascularization index (VI), flow index and vascularization flow index (VFI) in the endometrium and in a 2-mm 'shell' surrounding the endometrium. The 'gold standard' was the histological diagnosis of the endometrium obtained by hysteroscopic resection of focal lesions, dilatation and curettage or hysterectomy. Receiver-operating characteristics (ROC) curves were drawn for all measurements to evaluate their ability to distinguish between benign and malignant endometrium. Multivariate logistic regression analysis was used to create mathematical models to estimate the risk of endometrial malignancy.

RESULTS

There were 49 benign and 13 malignant endometria. Endometrial thickness and volume were significantly larger in malignant than in benign endometria, and flow indices in the endometrium and endometrial shell were significantly higher. The area under the ROC curve (AUC) of endometrial thickness was 0.82, that of endometrial volume 0.78, and that of the two best power Doppler variables (VI and VFI in the endometrium) 0.82 and 0.82. The best logistic regression model for predicting malignancy contained the variables endometrial thickness (odds ratio 1.2; 95% CI, 1.04-1.30; P = 0.004) and VI in the endometrial 'shell' (odds ratio 1.1; 95% CI, 1.02-1.23; P = 0.01). Its AUC was 0.86. Using its mathematically optimal risk cut-off value (0.22), the model correctly classified seven more benign cases but two fewer malignant cases than the best endometrial thickness cut-off (11.8 mm). Models containing endometrial volume and flow indices performed less well than did endometrial thickness alone (AUC, 0.79 vs. 0.82).

CONCLUSIONS

The diagnostic performance for discrimination between benign and malignant endometrium of 3D ultrasound imaging was not superior to that of endometrial thickness as measured by 2D ultrasound examination, and 3D power Doppler imaging added little to endometrial thickness or volume.

Adnexal mass vascularity assessed by 3-dimensional power Doppler: does it add to the risk of malignancy index in prediction of ovarian malignancy?: four hundred-case study

The Risk of Malignancy Index (RMI) is used for the prediction of ovarian malignancy. It includes menopausal status, carbohydrate antigen 125 serum levels, and ultrasound criteria. Three-dimensional power Doppler (3-DPD) is a reproducible investigation for assessment of tumor vascularity, classifying vascularity to avascular, parallel, and chaotic patterns. In this study; 3-DPD was added to RMI for prediction of malignancy in 400 cases of ovarian masses. Sensitivity of RMI for prediction of malignancy was 88%, with a cutoff value of 202.5 at 95% confidence interval. Sensitivity of 3-DPD for prediction of malignancy was 75%, adding 3-DPD to RMI increased its sensitivity to 99%. Considering the pilot nature of the study, further studies are needed to corroborate such findings.

[French recommendations for ovarian cancer management during pregnancy]

Evaluation of the fetus using prenatal ultrasound has resulted in increased detection of asymptomatic adnexal masses during pregnancy. Such masses are rarely malignant (1/10 000 to 1/50 000 pregnancies), but the possibility of borderline or cancer must be considered. It is a common assumption by both patients and physicians that if an ovarian cancer is diagnosed during pregnancy, treatment necessitates sacrificing the well-being of the fetus. However, in most cases, it is possible to offer appropriate treatment to the mother without placing the fetus at serious risk. The care of a pregnant woman with cancer involves evaluation of sometimes competing maternal and fetal risks and benefits. These recommendation approaches attempt to balance these risks and benefits; however, they should be considered advisory and should not replace specific interdisciplinary consultation with specialists in maternal-fetal medicine, gynecologic oncology, and pediatrics, as well as imaging and pathology, as needed. Second level ultrasound including Doppler is needed. MRI is not often necessary, and CA 125 is of low contribution. We suggest surgery be performed after 15 SA for ovarian masses which (1) persist into the second trimester, (2) are greater than 5 to 10 cm in diameter, or (3) have solid or mixed solid and cystic ultrasound characteristics. During antepartum surgical staging and debulking, homolateral salpingo-oophorectomy and peritoneal cytology and exploration are necessary. Women found to have advanced stage epithelial ovarian cancer should consider having completion of the debulking of the reproductive organs at the conclusion of the pregnancy. If chemotherapy is indicated, we recommend delaying administration, if possible, after the delivery or at least after 20 SA in order to minimize the potential fetal toxicity.

Preoperative diagnosis of ovarian malignancy: preliminary results of the use of 3-dimensional vascular ultrasound

OBJECTIVE

To estimate the accuracy of 3-dimensional (3D) vascular ultrasound in the preoperative assessment of pelvic masses for malignancy.

METHODS

We performed a chart review of 66 patients who underwent 3D ultrasound for pelvic masses. Each mass was preoperatively judged to be benign or malignant based upon a study of vascularity within an ovarian mass using 3D ultrasound. Masses with orderly vascular architecture were categorized as probably benign, and masses with chaotic vascular patterns were categorized as malignant. The predictive value of 3D vascular ultrasound was compared with that of 2-dimensional ultrasound and cancer antigen 125 as a predictor of malignancy.

RESULTS

Among the 66 patients examined, 34 underwent a documented surgical intervention. Of those 34 patients, 10 had primary malignant neoplasms including 2 with low-malignant potential tumors. Suspicious 3D vascular ultrasound findings predicted malignant neoplasm in 10 patients. Two patients had recurrent cancer; however, only 1 had a suspicious ultrasound finding. There was 1 case of a low-malignant potential tumor without a suspicious ultrasound finding. Excluding the recurrent cancers and the observed patients, the positive predictive value (PPV) and the negative predictive value (NPV) of 3D vascular ultrasound were 100% and 95%, respectively. The PPV and the NPV of 2-dimensional ultrasound in predicting malignancy were 37% and 100%, respectively. An abnormal level of cancer antigen 125 had a PPV and an NPV of 73% and 83%, respectively, in this patient population.

CONCLUSIONS

In this preliminary and observational study, 3D ultrasound examination of vascular architecture was discriminatory in distinguishing benign ovarian masses from malignancy. Chaotic vascular architecture correlated with malignancy in this group of high-risk patients.

Evaluation of two different methods for vascular sampling by three-dimensional power Doppler angiography in solid and cystic-solid adnexal masses

OBJECTIVE

To analyze two different methods for performing three-dimensional power Doppler angiography (3D-PDA) vascular sampling in solid and cystic-solid adnexal masses.

METHODS

Twenty-one 3D-PDA volumes from 18 consecutive and unselected solid or cystic-solid adnexal masses (13 malignant and five benign) were analyzed. A single examiner (J. L. A.) acquired all the volumes according to a predetermined scanning protocol. Two different observers (one inexperienced and the other experienced) calculated 3D-PDA vascular indices (vascularization index (VI), flow index (FI) and vascularization flow index (VFI)) from solid tumor areas. First, manual sampling (Plane A, 15 degrees rotation-step) was performed, and 1 week later 5-cm(3) sphere sampling from the most vascularized area was carried out. The observers made a record of any difficulty that they encountered in delineating the solid areas of tumors or in distinguishing true tumor vessels from pre-existing vessels, the time spent performing each analysis was recorded and inter- and intraobserver reproducibility was evaluated for each method using intraclass correlation coefficients (ICC).

RESULTS

In four (19.0%) of the 21 volumes sphere sampling could not be performed because it was not possible to obtain a sphere smaller than 5.5 cm(3). This happened in cases in which image zooming was used when acquiring the 3D volume. The inexperienced observer encountered more difficulty, but not significantly more, than the experienced observer when analyzing 3D-PDA volumes both by manual sampling (29% vs. 14% of cases) and 5-cm(3) sphere sampling (35% vs. 18% of cases). The mean time spent by the inexperienced observer was significantly greater (P < 0.001) than that spent by the experienced observer both for manual sampling (6.11 min vs. 1.85 min) and 5-cm(3) sphere sampling (2.93 min vs. 2.15 min). Contrary to the findings for the experienced observer, the inexperienced observer required less time to perform sphere sampling than they did manual sampling. Interobserver agreement was high for both methods: ICC for manual volume, 0.993; manual VI, 0.908; manual FI, 0.913; manual VFI, 0.914; sphere volume, 0.949; sphere VI, 0.954; sphere FI 0.850; and sphere VFI, 0.953. Intraobserver reproducibility was also high, with all ICCs above 0.99.

CONCLUSIONS

Manual and 5-cm(3) sphere sampling are reproducible methods for 3D-PDA vascular sampling. Caution is required when image zoom is used at the time of acquiring the volume because this may prevent sphere sampling. Difficulties found in performing both manual and sphere sampling do not seem to significantly affect the reproducibility of Doppler index calculations.