Three-dimensional sonographic morphologic assessment of adnexal masses: a reproducibility study

Is three-dimensional ultrasonography a valuable diagnostic tool for patients with ovarian cancer? Systematic review and meta-analysis

Introduction

This paper was to assess the diagnostic performance and clinical value of three-dimensional ultrasonography (3DUS), three-dimensional ultrasonography power Doppler (3DPD), and 3DUS combined with 3DPD in ovarian cancer (OC).

Methods

The study was registered with PROSPERO (CRD 42023405765). PubMed and Web of Science were searched from inception to 25 January 2022, and reference lists of potentially eligible studies were also manually searched. Patient and study characteristics were extracted by two independent reviewers. Any discrepancies were addressed through discussion. The sensitivity, specificity, positive and negative likelihood ratio (PLR and NLR, respectively), and the area under the receiver operating characteristic curve (AUC) were pooled separately.

Results

We retrieved 2,566 studies, of which 18 were finally enrolled, with 2,548 cases. The pooled sensitivity, specificity, PLR, NLR, and AUC for 3DUS were 0.89 (95% CI: 0.85-0.93), 0.93 (95% CI: 0.88-0.96), 13.1 (95% CI: 7.3-23.4), 0.11 (95% CI: 0.08-0.16), and 0.90 (95% CI: 0.87-0.93), respectively. The pooled sensitivity, specificity, PLR, NLR, and AUC for 3DPD were 0.90 (95% CI: 0.80-0.95), 0.85 (95% CI: 0.71-0.92), 5.8 (95% CI: 3.0-11.2), 0.12 (95% CI: 0.06-0.24), and 0.94 (95% CI: 0.91-0.96), respectively. The pooled sensitivity, specificity, PLR, NLR, and AUC for 3DUS combined with 3DPD were 0.99 (95% CI: 0.73-1.00), 0.95 (95% CI: 0.85-0.99), 21.9 (95% CI: 6.1-78.9), 0.01 (95% CI: 0.00-0.37), and 0.99 (95% CI: 0.98-1.00), respectively.

Conclusions

3DUS, 3DPD, and 3DUS combined with 3DPD are promising diagnostic tools for OC, alongside elevated sensitivity and specificity. However, the combination of 3DUS and 3DPD techniques has higher diagnostic efficiency.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD 42023405765.

The Reproducibility of Ultrasonographic Findings of Rectosigmoid Endometriosis Among Examiners With Different Level of Expertise

OBJECTIVE

To analyze the reproducibility of ultrasonographic (US) findings of rectosigmoid endometriosis among examiners with different level of expertise using stored three-dimensional (3D) volumes of the posterior compartment of the pelvis as a part of SANABA (Sardinia-Navarra-Barcelona) collaborative study.

MATERIALS AND METHODS

Six examiners in 3 academic Department of Obstetrics and Gynecology, with different levels of experience and blinded to each other, evaluated 60 stored 3D volumes from the posterior compartment of the pelvis and looked for the presence or absence of features of rectosigmoid endometriotic lesions defined as an irregular hypoechoic nodule with or without hypoechoic foci at the level of the muscularis propria of the anterior wall rectum sigma. Multiplanar view and virtual navigation were used. All examiners had to assess the 3D volume of posterior compartment of the pelvis and classify it as present or absent disease. To analyze intra-observer and the inter-observer agreements, each examiner performed the assessment twice with a 2-week interval between the first and second assessments. Reproducibility was assessed by calculating the weighted Kappa index.

RESULTS

Intra-observer reproducibility was moderate to very good for all observers (Kappa index ranging from 0.49 to 0.96) associated with a good diagnostic accuracy of each reader. Inter-observer reproducibility was fair to very good (Kappa index range: 0.21-0.87).

CONCLUSIONS

The typical US sign of rectosigmoid endometriosis is reasonably recognizable to observers with different level of expertise when assessed in stored 3D volumes.

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.

Role of Three-Dimensional Ultrasound in Gynecology

Three-dimensional ultrasound (3D USG) is a fast-evolving imaging technique that holds a great potential for use in gynecology. Its sensitivity and specificity is reported to be close to 100 % for diagnosing congenital uterine anomalies, comparable with those of magnetic resonance imaging (MRI) and laparoscopy. With 3D USG, a coronal view of the uterus can be obtained, clearly outlining the external contour of the uterus and providing accurate information about the shape of the cavity. Although 3D USG may not perform well in thin endometria, combining it with saline infusion sonography (SIS) overcomes this problem. Research shows that 3D USG is more sensitive and specific than two-dimensional ultrasound (2D USG) in defining and mapping uterine lesions, such as fibroids, adenomyosis, and intrauterine synechia. In cases of suspected malignancy, 3D USG is mainly used in the initial evaluation of patients. Measuring various indices and mapping vascular architecture with 3D power Doppler have been proposed for evaluating adnexal masses. Although some studies raised hope, no consensus is reached about its use, success, and limitations. In urogynecology, translabial 3D USG is proved to be a valuable tool, as it provides instant access to the axial plane, which clearly depicts the relationship of the vagina, urethra, rectum, and the muscular pelvic floor. Studies report no significant differences between translabial 3D USG and MRI measurements for evaluation of the pelvic floor. In conclusion, adding 3D USG to routine gynecological workup can be beneficial for clinicians, as it provides fast and accurate results in a relatively cost-effective setting.

HDlive rendering image of adnexal tumors: preliminary report

BACKGROUND

Our objective is to present our first experience of adnexal tumors reconstructed employing the HDlive rendering mode.

METHODS

Seven adnexal tumors (one case each of chocolate cyst, benign cystic teratoma, serous cystadenofibroma, and torsion of the hydrosalpinx, and three cases of ovarian cancer) were studied using the HDlive rendering mode.

RESULTS

In the case of the chocolate cyst, the smooth inner wall with numerous tiny projections was clearly identified. In the case of benign cystic teratoma, a smooth hair ball inside the cyst was evident. In the case of the serous cystadenofibroma, a smooth, solid projection and relatively smooth septum were noted. In the three cases of ovarian cancer, numerous irregular papillae and irregular, thick septae were depicted. In the case of the bilateral hydrosalpinx with torsion of the right tube, different fluid contents were recognized.

CONCLUSION

The HDlive rendering mode provides anatomically realistic features such as macroscopic specimens for physicians and pathologists due to the complete depiction of the inner surface of the adnexal tumors.

Intensive training program for ultrasound diagnosis of adnexal masses: protocol and preliminary results

OBJECTIVE

To assess the feasibility of a specific training program for ultrasound diagnosis of adnexal masses.

METHODS

A 2-month intensive training program was developed. The program protocol consisted of a 1-day intensive theoretical course focused on clinical and sonographic issues related to adnexal masses and ovarian cancer, followed by a 4-week real-time ultrasound training program in a tertiary center (25-30 adnexal masses evaluated per month) and a final 4-week period for offline assessment of three-dimensional (3D) volumes from adnexal masses. In this final period, each trainee evaluated five sets of 100 3D volumes. 3D volumes contained gray-scale and power Doppler information, and the trainee was provided with clinical data for each case (patient age, menopausal status and reported symptoms). 3D volumes were obtained from surgically removed masses that had undergone histological diagnosis or from masses that had been followed up until resolution. After assessment of each set, the trainee's diagnostic performance was calculated (sensitivity and specificity) and each incorrectly classified mass was evaluated with the trainer. The objective was to achieve a sensitivity of > 95% and a specificity of > 90%. Learning curve cumulative summation (LC-CUSUM) graphs were plotted to assess the learning curve for the trainees.

RESULTS

One trainer and two trainees with little experience in gynecological ultrasound (one gynecologist and one radiologist) participated in this study. LC-CUSUM graphs showed that competence was achieved after 170 or 185 examinations. The objectives for diagnostic performance were achieved after assessment of the second set of 3D volumes (200 cases) for each trainee.

CONCLUSIONS

The proposed training program appears to be feasible. High diagnostic performance can be achieved after analysis of 200 cases and maintained thereafter.

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.

Intra- and interobserver variability of 2D and 3D transvaginal sonography in the diagnosis of benign versus malignant adnexal masses

PURPOSE

The purpose of this study was to investigate the intraobserver and interobserver agreements in the diagnosis of malignant versus benign adnexal masses using two-dimensional ultrasonography (2D US) and three-dimensional ultrasonography (3D US).

METHODS

Two experienced sonographers performed a retrospective review of digitally stored 2D images and 3D data from a sample of 41 consecutive patients with a diagnosis of adnexal mass. Each observer independently, and blinded to each other, evaluated the 2D static images of each adnexal mass and then the 3D volumes 1 week later. The observers were required to classify the adnexal lesion as benign or malignant according to pattern recognition analysis. Intraobserver and interobserver agreement were assessed by calculating the kappa index (κ).

RESULTS

Intraobserver agreement between 2D US and 3D US for the observer A was 1.00 and for the observer B was 0.69. Interobserver agreement was 0.69 for 2D US and 1.00 for 3D US (p > 0.05)

CONCLUSIONS

Although 3D US in the diagnosis of adnexal masses appeared more reproducible than 2D US, the difference was not statistically significant.

A new quantitative method to evaluate adnexal tumors

OBJECTIVE

The purpose of this study was to assess endometriomas and follicular cysts using a new quantitative method provided by the picture archiving and communication system.

MATERIALS AND METHODS

We reviewed our computer ultrasound database of endometriomas and follicular cysts between November 2003 and July 2007. A total of 123 consecutive women diagnosed with an endometrioma or follicular cyst on two-dimensional sonography were re-evaluated using new parameters with the picture archiving and communication system. We chose quantitative tumor density and standard deviation on sonographic images as the new diagnostic parameters. Analysis of variance and Scheffé post hoc test were analyzed to compare the mean tumor density of the endometriomas and follicular cysts. The receiver operating characteristic curve was plotted to choose the cutoff value of the endometrioma tumor density with the best sensitivity and specificity.

RESULTS

There was a significant difference when the tumor density of the follicular cyst and endometrioma groups was compared using the vaginal, abdominal or endovaginal approach (p < 0.001). Based on the results of the receiver operating characteristic curve, endovaginal ultrasonography is an excellent diagnostic tool with which to evaluate endometriomas. With endovaginal ultrasonography examination, the best cutoff value of tumor density is 28 and the sensitivity and specificity are 64% and 100%, respectively.

CONCLUSION

The use of quantitative tumor density and standard deviation on sonographic images is a potential new diagnostic tool in the assessment of endometriomas and follicular cysts.

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.

Detection of focal liver lesions: from the subjectivity of conventional ultrasound to the objectivity of volume ultrasound

PURPOSE

This study was undertaken to establish the reliability of automated volumetric liver scans in detecting focal liver lesions by evaluating the degree of agreement between conventional and volume ultrasound (US) examinations.

MATERIALS AND METHODS

Over a period of 3 months, we prospectively studied 100 consecutive patients (36 men and 64 women; age range 15-87 years; mean age 63 years) referred to our institute for US imaging of the liver. Volumetric acquisition of the liver was achieved with a 3D transducer (2.0-5.0 MHz) and a Logiq 9 US scanner. All patients underwent both 2- and 3D US studies performed by two expert radiologists. Volumetric acquisitions were subsequently reviewed by the second radiologist, who was blinded to the first radiologist's report. Three categories were established: 1=presence of focal liver lesions; 2=doubtful finding; 3=absence of focal liver lesions. Concordance between volume US and conventional US was calculated by using the k statistic.

RESULTS

Out of 100 patients examined, 39 were found to be affected by focal liver lesions. All volume US examinations were technically adequate, allowing exploration of all hepatic sectors, except for five cases that were marred by major respiratory motion artefacts. Conventional and volume US identified the same number of focal liver lesions, with the exception of four cases of doubtful findings at volume US. Concordance between automated volume US and conventional US of the liver was high (k=0.92).

CONCLUSIONS

The identification of focal liver lesions on automated volume US is possible, and the examination shows a high level of concordance with conventional US.

Three-dimensional power Doppler vascular network assessment of adnexal masses: intraobserver and interobserver agreement analysis

OBJECTIVE

The purpose of this study was to assess intraobserver and interobserver agreement for tumor vascular network evaluation as assessed by 3-dimensional (3D) power Doppler sonography for discriminating benign from malignant adnexal masses.

METHODS

Stored 3D power Doppler angiographic volume data from 39 women with a diagnosis of a vascularized adnexal mass who were evaluated and treated at our institution were retrieved from our database for analysis. Two different examiners (observer A, with 6 years of experience in 3D sonography; and observer B, with 1 year of experience) reviewed 3D sonograms blinded to each other. Three-dimensional vascular network reconstruction was done with surface rendering in the color mode. Malignancy was considered in the presence of at least 2 of the following: irregular branching, vessel caliber changes, microaneurysms, and vascular lakes. A definitive histologic diagnosis was obtained in all cases. Intraobserver and interobserver agreement rates were estimated by calculating the kappa index.

RESULTS

Twenty (51%) tumors were malignant, and 19 (49%) were benign. Intraobserver agreement was good for observer A (kappa = 0.69) and moderate for observer B (kappa = 0.54). Interobserver agreement was moderate (kappa = 0.49).

CONCLUSIONS

We found intraobserver and interobserver agreement to be moderate for 3D power Doppler assessment of the vascular network in adnexal masses.