ACR Appropriateness Criteria® Clinically Suspected Adnexal Mass, No Acute Symptoms: 2023 Update

Asymptomatic adnexal masses are commonly encountered in daily radiology practice. Although the vast majority of these masses are benign, a small subset have a risk of malignancy, which require gynecologic oncology referral for best treatment outcomes. Ultrasound, using a combination of both transabdominal, transvaginal, and duplex Doppler technique can accurately characterize the majority of these lesions. MRI with and without contrast is a useful complementary modality that can help characterize indeterminate lesions and assess the risk of malignancy is those that are suspicious. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Bridging Communication Gaps Between Radiologists, Referring Physicians, and Patients Through Standardized Structured Cancer Imaging Reporting: The Experience with Female Pelvic MRI Assessment Using O-RADS and a Simulated Cohort Patient Group

RATIONALE AND OBJECTIVES

This study aimed to evaluate whether implementing structured reporting based on Ovarian-Adnexal Reporting and Data System (O-RADS) magnetic resonance imaging (MRI) in women with sonographically indeterminate adnexal masses improves communication between radiologists, referrers, and patients/caregivers and enhances diagnostic performance for determining adnexal malignancy.

MATERIALS AND METHODS

We retrospectively analyzed prospectively issued MRI reports in 2019-2022 performed for characterizing adnexal masses before and after implementing O-RADS MRI; 56 patients/caregivers and nine gynecologic oncologists ("referrers") were surveyed about report interpretability/clarity/satisfaction; responses for pre- and post-implementation reports were compared using Fisher's exact and Chi-squared tests. Diagnostic performance was assessed using receiver operating characteristic curves.

RESULTS

A total of 123 reports from before and 119 reports from after O-RADS MRI implementation were included. Survey response rates were 35.7% (20/56) for patients/caregivers and 66.7% (6/9) for referrers. For patients/caregivers, O-RADS MRI reports were clearer (p < 0.001) and more satisfactory (p < 0.001) than unstructured reports, but interpretability did not differ significantly (p = 0.14), as 28.0% (28/100) of postimplementation and 38.0% (38/100) of preimplementation reports were considered difficult to interpret. For referrers, O-RADS MRI reports were clearer, more satisfactory, and easier to interpret (p < 0.001); only 1.3% (1/77) were considered difficult to interpret. For differentiating benign from malignant adnexal lesions, O-RADS MRI showed area under the curve of 0.92 (95% confidence interval [CI], 0.85-0.99), sensitivity of 0.81 (95% CI, 0.58-0.95), and specificity of 0.91 (95% CI, 0.83-0.96). Diagnostic performance of reports before implementation could not be calculated due to many different phrases used to describe the likelihood of malignancy.

CONCLUSION

Implementing standardized structured reporting using O-RADS MRI for characterizing adnexal masses improved clarity and satisfaction for patients/caregivers and referrers. Interpretability improved for referrers but remained limited for patients/caregivers.

Society of Radiologists in Ultrasound Consensus on Routine Pelvic US for Endometriosis

Endometriosis is a prevalent and potentially debilitating condition that mostly affects individuals of reproductive age, and often has a substantial diagnostic delay. US is usually the first-line imaging modality used when patients report chronic pelvic pain or have issues of infertility, both common symptoms of endometriosis. Other than the visualization of an endometrioma, sonologists frequently do not appreciate endometriosis on routine transvaginal US images. Given a substantial body of literature describing techniques to depict endometriosis at US, the Society of Radiologists in Ultrasound convened a multidisciplinary panel of experts to make recommendations aimed at improving the screening process for endometriosis. The panel was composed of experts in the imaging and management of endometriosis, including radiologists, sonographers, gynecologists, reproductive endocrinologists, and minimally invasive gynecologic surgeons. A comprehensive literature review combined with a modified Delphi technique achieved a consensus. This statement defines the targeted screening population, describes techniques for augmenting pelvic US, establishes direct and indirect observations for endometriosis at US, creates an observational grading and reporting system, and makes recommendations for additional imaging and patient management. The panel recommends transvaginal US of the posterior compartment, observation of the relative positioning of the uterus and ovaries, and the uterine sliding sign maneuver to improve the detection of endometriosis. These additional techniques can be performed in 5 minutes or less and could ultimately decrease the delay of an endometriosis diagnosis in at-risk patients.

O-RADS US v2022: An Update from the American College of Radiology's Ovarian-Adnexal Reporting and Data System US Committee

First published in 2019, the Ovarian-Adnexal Reporting and Data System (O-RADS) US provides a standardized lexicon for ovarian and adnexal lesions, enables stratification of these lesions with use of a numeric score based on morphologic features to indicate the risk of malignancy, and offers management guidance. This risk stratification system has subsequently been validated in retrospective studies and has yielded good interreader concordance, even with users of different levels of expertise. As use of the system increased, it was recognized that an update was needed to address certain clinical challenges, clarify recommendations, and incorporate emerging data from validation studies. Additional morphologic features that favor benignity, such as the bilocular feature for cysts without solid components and shadowing for solid lesions with smooth contours, were added to O-RADS US for optimal risk-appropriate scoring. As O-RADS US 4 has been shown to be an appropriate cutoff for malignancy, it is now recommended that lower-risk O-RADS US 3 lesions be followed with US if not excised. For solid lesions and cystic lesions with solid components, further characterization with MRI is now emphasized as a supplemental evaluation method, as MRI may provide higher specificity. This statement summarizes the updates to the governing concepts, lexicon terminology and assessment categories, and management recommendations found in the 2022 version of O-RADS US.

Diagnostic Performance of Ultrasonography-Based Risk Models in Differentiating Between Benign and Malignant Ovarian Tumors in a US Cohort

Importance

Ultrasonography-based risk models can help nonexpert clinicians evaluate adnexal lesions and reduce surgical interventions for benign tumors. Yet, these models have limited uptake in the US, and studies comparing their diagnostic accuracy are lacking.

Objective

To evaluate, in a US cohort, the diagnostic performance of 3 ultrasonography-based risk models for differentiating between benign and malignant adnexal lesions: International Ovarian Tumor Analysis (IOTA) Simple Rules with inconclusive cases reclassified as malignant or reevaluated by an expert, IOTA Assessment of Different Neoplasias in the Adnexa (ADNEX), and Ovarian-Adnexal Reporting and Data System (O-RADS).

Design, Setting, and Participants

This retrospective diagnostic study was conducted at a single US academic medical center and included consecutive patients aged 18 to 89 years with adnexal masses that were managed surgically or conservatively between January 2017 and October 2022.

Exposure

Evaluation of adnexal lesions using the Simple Rules, ADNEX, and O-RADS.

Main Outcomes and Measures

The main outcome was diagnostic performance, including area under the receiver operating characteristic (ROC) curve (AUC), sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios. Surgery or follow-up were reference standards. Secondary analyses evaluated the models' performances stratified by menopause status and race.

Results

The cohort included 511 female patients with a 15.9% malignant tumor prevalence (81 patients). Mean (SD) ages of patients with benign and malignant adnexal lesions were 44.1 (14.4) and 52.5 (15.2) years, respectively, and 200 (39.1%) were postmenopausal. In the ROC analysis, the AUCs for discriminative performance of the ADNEX and O-RADS models were 0.96 (95% CI, 0.93-0.98) and 0.92 (95% CI, 0.90-0.95), respectively. After converting the ADNEX continuous individualized risk into the discrete ordinal categories of O-RADS, the ADNEX performance was reduced to an AUC of 0.93 (95% CI, 0.90-0.96), which was similar to that for O-RADS. The Simple Rules combined with expert reevaluation had 93.8% sensitivity (95% CI, 86.2%-98.0%) and 91.9% specificity (95% CI, 88.9%-94.3%), and the Simple Rules combined with malignant classification had 93.8% sensitivity (95% CI, 86.2%-98.0%) and 88.1% specificity (95% CI, 84.7%-91.0%). At a 10% risk threshold, ADNEX had 91.4% sensitivity (95% CI, 83.0%-96.5%) and 86.3% specificity (95% CI, 82.7%-89.4%) and O-RADS had 98.8% sensitivity (95% CI, 93.3%-100%) and 74.4% specificity (95% CI, 70.0%-78.5%). The specificities of all models were significantly lower in the postmenopausal group. Subgroup analysis revealed high performances independent of race.

Conclusions and Relevance

In this diagnostic study of a US cohort, the Simple Rules, ADNEX, and O-RADS models performed well in differentiating between benign and malignant adnexal lesions; this outcome has been previously reported primarily in European populations. Risk stratification models can lead to more accurate and consistent evaluations of adnexal masses, especially when used by nonexpert clinicians, and may reduce unnecessary surgeries.

Adnexal Mass Imaging: Contemporary Guidelines for Clinical Practice

Several recent guidelines have been published to improve accuracy and consistency of adnexal mass imaging interpretation and to guide management. Guidance from the American College of Radiology (ACR) Appropriateness Criteria establishes preferred adnexal imaging modalities and follow-up. Moreover, the ACR Ovarian-Adnexal Reporting Data System establishes a comprehensive, unified set of evidence-based guidelines for classification of adnexal masses by both ultrasound and MR imaging, communicating risk of malignancy to further guide management.

Advantages and Limitations of Ultrasound as a Screening Test for Ovarian Cancer

Ovarian cancer (OC) is the seventh most common malignancy diagnosed among women, the eighth leading cause of cancer mortality globally, and the most common cause of death among all gynecological cancers. Even though recent advances in technology have allowed for more accurate radiological and laboratory diagnostic tests, approximately 60% of OC cases are diagnosed at an advanced stage. Given the high mortality rate of advanced stages of OC, early diagnosis remains the main prognostic factor. Our aim is to focus on the sonographic challenges in ovarian cancer screening and to highlight the importance of sonographic evaluation, the crucial role of the operator΄s experience, possible limitations in visibility, emphasizing the importance and the necessity of quality assurance protocols that health workers have to follow and finally increasing the positive predictive value. We also analyzed how ultrasound can be combined with biomarkers (ex. CA-125) so as to increase the sensitivity of early-stage OC detection or, in addition to the gold standard examination, the CT (Computed tomography) scan in OC follow-up. Improvements in the performance and consistency of ultrasound screening could reduce the need for repeated examinations and, mainly, ensure diagnostic accuracy. Finally, we refer to new very promising techniques such as liquid biopsies. Future attempts in order to improve screening should focus on the identification of features that are unique to OC and that are present in early-stage tumors.

The Ovarian/Adnexal Reporting and Data System for Ultrasound: From Standardized Terminology to Optimal Risk Assessment and Management

The American College of Radiology (ACR) Ovarian-Adnexal Reporting and Data System (O-RADS) lexicon and risk assessment tool for ultrasound (US) provides a framework for characterization of ovarian and adnexal pathology with the ultimate goal of harmonizing reporting and patient management strategies. Since the first O-RADS US publication in 2018, multiple validation studies have shown O-RADS US to have excellent diagnostic accuracy, with the majority of these studies using O-RADS 4 as the optimal cut-off for detecting ovarian cancer. Most of the existing validation studies include a dedicated training phase and confirm that ORADS US categories and lexicon descriptors are associated with high level inter-read agreement, regardless of radiologist training level or practice experience. O-RADS US has a similar inter-reader agreement when compared to Gynecologic Imaging Reporting and Data System (GIRADS), Assessment of Different Neoplasias in the adnexa (ADNEX), and International Tumor Analysis Group (IOTA) simple rules. System descriptors have been shown to correlate with expected malignancy rates and the O-RADS US risk stratification system has been shown to perform in the expected range of malignancy risk per category. Further directions will focus on clarifying governing concepts and lexicon terminology as well as further refining risk stratification categories based on data from published validation studies.

Spectrum of Ovarian Incidentalomas: Diagnosis and Management

Incidental ovarian lesions are asymptomatic lesions that are accidentally discovered during a CT or MRI examinations that involves the pelvic cavity or during a routine obstetric ultrasound study. Incidental ovarian masses are usually benign with a very low risk of malignancy yet underlying malignant pathology may be discovered during the diagnostic work-up of these lesions. Suspicion of malignancy is directly correlating with the increase in the patient's age, the increase in the size of the lesion, the presence of the solid components or thick septa and a high color scale of the ovarian mass. Following standard reporting and management protocols are essential to choose the proper work-up of these lesions to avoid unnecessary additional imaging and operative intervention. In this article, we will provide a review of the characteristic imaging features of some incidental and yet commonly encountered ovarian lesions. We will also summarize the recently published algorithms that are important for consistent reporting and standard management of these lesions.

Fat-containing adnexal masses on MRI: solid tissue volume and fat distribution as a guide for O-RADS Score assignment

PURPOSE

To explore ways to improve O-RADS MRI scoring for fat-containing adnexal masses, by investigating methods for quantifying solid tissue volume and fat distribution and evaluating their associations with malignancy.

METHODS

This retrospective, single-center study included patients with fat-containing adnexal masses on MRI during 2008-2021. Two radiologists independently reviewed overall size (Sizeoverall), size of any solid tissue (Sizeanysolid), size of solid tissue that was not Rokitansky nodule (Sizenon-Rokitansky), and fat distribution. Wilcoxon test, Fisher-exact test, and ROC curve analysis were performed. Reference standard was pathology or follow-up > 24 months.

RESULTS

188 women (median age 35 years) with 163 benign and 25 malignant lesions were included. Sizeoverall (R1, 9.9 cm vs 5.9 cm; R2, 12.4 cm vs 6.0 cm), Sizeanysolid (R1, 5.1 cm vs 1.2 cm; R2, 3.2 cm vs 0.0 cm), Sizenon-Rokitansky (R1, 5.1 cm vs 0.0 cm; R2, 3.1 cm vs 0.0 cm), and fat distribution differed significantly between malignant and benign lesions (p < 0.01). Area under ROC curve was greatest using Sizenon-Rokitansky (R1, 0.83; R2, 0.86) vs Sizeoverall (R1, 0.78; R2, 0.81) or Sizeanysolid (R1, 0.79; R2, 0.81), though differences were non-significant (p = 0.48-0.93). Cutoffs for Sizenon-Rokitansky (R1, ≥ 1.2 cm; R2, ≥ 1.0 cm) yielded sensitivity and specificity of 0.72 and 0.93 (R1) and 0.76 and 0.95 (R2). Among immature teratomas, 85.7% displayed scattered fat.

CONCLUSION

Overall size, size of (any or non-Rokitansky-nodule) solid tissue, and fat distribution differed between benign and malignant fat-containing adnexal masses. Incorporating these would constitute simple and practical approaches to refining O-RADS MRI scoring.

Interobserver agreement between eight observers using IOTA simple rules and O-RADS lexicon descriptors for adnexal masses

PURPOSE

To evaluate interobserver agreement in assigning imaging features and classifying adnexal masses using the IOTA simple rules versus O-RADS lexicon and identify causes of discrepancy.

METHODS

Pelvic ultrasound (US) examinations in 114 women with 118 adnexal masses were evaluated by eight radiologists blinded to the final diagnosis (4 attendings and 4 fellows) using IOTA simple rules and O-RADS lexicon. Each feature category was analyzed for interobserver agreement using intraclass correlation coefficient (ICC) for ordinal variables and free marginal kappa for nominal variables. The two-tailed significance level (a) was set at 0.05.

RESULTS

For IOTA simple rules, interobserver agreement was almost perfect for three malignant lesion categories (M2-4) and substantial for the remaining two (M1, M5) with k-values of 0.80-0.82 and 0.68-0.69, respectively. Interobserver agreement was almost perfect for two benign feature categories (B2, B3), substantial for two (B4, B5) and moderate for one (B1) with k-values of 0.81-0.90, 0.69-0.70 and 0.60, respectively. For O-RADS, interobserver agreement was almost perfect for two out of ten feature categories (ascites and peritoneal nodules) with k-values of 0.89 and 0.97. Interobserver agreement ranged from fair to substantial for the remaining eight feature categories with k-values of 0.39-0.61. Fellows and attendings had ICC values of 0.725 and 0.517, respectively.

CONCLUSION

O-RADS had variable interobserver agreement with overall good agreement. IOTA simple rules had more uniform interobserver agreement with overall excellent agreement. Greater reader experience did not improve interobserver agreement with O-RADS.

Ovarian Cystadenomas: Growth Rate and Reliability of Imaging Measurements

OBJECTIVES

To evaluate the growth rate of benign ovarian cystadenomas and the degree of variability in ultrasound measurements.

METHODS

Two independent retrospective cohorts of women found to have benign cystadenomas at surgery were identified. To assess growth rate, ultrasounds on women in a community-based health system were reviewed and the growth rate was determined based on the maximum reported size dimension using a mixed effect model. To assess measurement variability, two radiologists independently measured presurgical adnexal imaging findings for women in a tertiary care referral setting. Interobserver, intra-observer, and intermodality (cine clip versus still images) variability in measurements was determined using correlation coefficients (CC) and Bland-Altman analysis, with the proportion of measurements varying by more than 1 cm calculated.

RESULTS

For growth rate assessment, 405 women with 1412 ultrasound examinations were identified. The median growth rate was 0.65 cm/year with mucinous cystadenomas growing faster at 0.83 cm/year compared to 0.51 cm/year for serous cystadenomas (median test P < .0001). To evaluate measurement variability, 75 women were identified with 176 ultrasound studies. The within-subject standard deviations for ultrasound measurements were 0.74 cm for cine clip images and 0.41 cm for static images, with 11% of measurements overall differing by more than 1 cm.

CONCLUSIONS

Cystadenomas grow on average 0.65 cm/year, which is similar in magnitude to the inherent error observed in measurement on ultrasound, suggesting that repeat ultrasound at intervals of longer than a year will often be needed to accurately assess growth if a cyst represents a benign cystadenoma.

Management of the Adnexal Mass: Considerations for the Family Medicine Physician

Ovarian cancer is the most deadly gynecological cancer, so proper assessment of a pelvic mass is necessary in order to determine which are at high risk for malignancy and should be referred to a gynecologic oncologist. However, in a family medicine setting, evaluation and treatment of these masses can be challenging due to a lack of resources. A number of risk assessment tools are available to family medicine physicians, including imaging techniques, imaging systems, and blood-based biomarker assays each with their respective pros and cons, and varying ability to detect malignancy in pelvic masses. Effective utilization of these assessment tools can inform the care pathway for patients which present with an adnexal mass, such as expectant management for those with a low risk of malignancy, or referral to a gynecologic oncologist for surgery and staging, for those at high risk of malignancy. Triaging patients to the appropriate care pathway improves patient outcomes and satisfaction, and family medicine physicians can play a key role in this decision-making process.

Diagnostic Performance of the Ovarian-Adnexal Reporting and Data System (O-RADS) Ultrasound Risk Score in Women in the United States

IMPORTANCE

The American College of Radiology (ACR) Ovarian-Adnexal Reporting and Data System (O-RADS) ultrasound (US) risk scoring system has been studied in a selected population of women referred for suspected or known adnexal lesions. This population has a higher frequency of malignant neoplasms than women presenting to radiology departments for pelvic ultrasonography for a variety of indications, potentially impacting the diagnostic performance of the risk scoring system.

OBJECTIVE

To evaluate the risk of malignant neoplasm and diagnostic performance of O-RADS US risk scoring system in a multi-institutional, nonselected cohort.

DESIGN, SETTING, AND PARTICIPANTS

This multi-institutional cohort study included a population of nonselected women in the United States who presented to radiology departments for routine pelvic ultrasonography between 2011 and 2014, with pathology confirmation imaging follow up or 2 years of clinical follow up.

EXPOSURE

Analysis of 1014 adnexal lesions using the O-RADS US risk stratification system.

MAIN OUTCOMES AND MEASURES

Frequency of ovarian cancer and diagnostic performance of the O-RADS US risk stratification system.

RESULTS

This study included 913 women with 1014 adnexal lesions. The mean (SD) age of the patients was 42.4 (13.9 years), and 674 of 913 (73.8%) were premenopausal. The overall frequency of malignant neoplasm was 8.4% (85 of 1014 adnexal lesions). The frequency of malignant neoplasm for O-RADS US 2 was 0.5% (3 of 657 lesions; <1% expected); O-RADS US 3, 4.5% (5 of 112 lesions; <10% expected); O-RADS US 4, 11.6% (18 of 155; 10%-50% expected); and O-RADS 5, 65.6% (59 of 90 lesions; >50% expected). O-RADS US 4 was the optimum cutoff for diagnosing cancer with sensitivity of 90.6% (95% CI, 82.3%-95.9%), specificity of 81.9% (95% CI, 79.3%-84.3%), positive predictive value of 31.4% (95% CI, 25.7%-37.7%) and negative predictive value of 99.0% (95% CI, 98.0%-99.6%).

CONCLUSIONS AND RELEVANCE

In this cohort study of a nonselected patient population, the O-RADS US risk stratification system performed within the expected range as published by the ACR O-RADS US committee. The frequency of malignant neoplasm was at the lower end of the published range, partially because of the lower prevalence of cancer in a nonselected population. However, a high negative predictive value was maintained, and when a lesion can be classified as an O-RADS US 2, the risk of cancer is low, which is reassuring for both clinician and patient.

Ovarian Cancer Detection in Average-Risk Women: Classic- versus Nonclassic-appearing Adnexal Lesions at US

Background Several US risk stratification schemas for assessing adnexal lesions exist. These multiple-subcategory systems may be more multifaceted than necessary for isolated adnexal lesions in average-risk women. Purpose To explore whether a US-based classification scheme of classic versus nonclassic appearance can be used to help appropriately triage women at average risk of ovarian cancer without compromising diagnostic performance. Materials and Methods This retrospective multicenter study included isolated ovarian lesions identified at pelvic US performed between January 2011 and June 2014, reviewed between September 2019 and September 2020. Lesions were considered isolated in the absence of ascites or peritoneal implants. Lesions were classified as classic or nonclassic based on sonographic appearance. Classic lesions included simple cysts, hemorrhagic cysts, endometriomas, and dermoids. Otherwise, lesions were considered nonclassic. Outcomes based on histopathologic results or clinical or imaging follow-up were recorded. Diagnostic performance and frequency of malignancy were calculated. Frequency of malignancy between age groups was compared using the χ² test, and Poisson regression was used to explore relationships between imaging features and malignancy. Results A total of 970 isolated lesions in 878 women (mean age, 42 years ± 14 [SD]) were included. The malignancy rate for classic lesions was less than 1%. Of 970 lesions, 53 (6%) were malignant. The malignancy rate for nonclassic lesions was 32% (33 of 103) when blood flow was present and 8% (16 of 194) without blood flow (P < .001). For women older than 60 years, the malignancy rate was 50% (10 of 20 lesions) when blood flow was present and 13% (five of 38) without blood flow (P = .004). The sensitivity, specificity, positive predictive value, and negative predictive value of the classic-versus-nonclassic schema was 93% (49 of 53 lesions), 73% (669 of 917 lesions), 17% (49 of 297 lesions), and 99% (669 of 673 lesions), respectively, for detection of malignancy. Conclusion Using a US classification schema of classic- or nonclassic-appearing adnexal lesions resulted in high sensitivity and specificity in the diagnosis of malignancy in ovarian cancer. The highest risk of cancer was in isolated nonclassic lesions with blood flow in women older than 60 years. © RSNA, 2022 See also the editorial by Baumgarten in this issue.

Benign-appearing Incidental Adnexal Cysts at US, CT, and MRI: Putting the ACR, O-RADS, and SRU Guidelines All Together

Adnexal cysts are a common incidental finding at US, CT, and MRI but have historically caused a diagnostic dilemma for determining when to follow up and how to manage them. Characteristic imaging features of simple adnexal cysts include a simple fluid collection with smooth walls and no solid or vascular components. Day-to-day practice guidelines were recently updated to reflect the overwhelming evidence that incidental cystic adnexal masses are almost always benign. Three major consensus articles on adnexal cystic masses were published between 2019 and 2020: the Society of Radiologists in Ultrasound (SRU) consensus update on adnexal cysts, the Ovarian-Adnexal Reporting and Data System (O-RADS) US consensus guideline, and the American College of Radiology (ACR) white paper on the management for incidental adnexal findings at CT and MRI. All three standardize reporting terminology, are based on evidence-based data and institutional practice patterns, and apply to nonpregnant women of average risk for ovarian cancer. While there are small differences in follow-up recommendations based on size thresholds, the goal of each is the same-to limit unnecessary imaging follow-up and, by doing so, save the patient time, money, and anxiety. For the diagnostic radiologist to use these guidelines, it is essential that the entire mass is visualized well. Without adequate visualization, further characterization of the mass may be necessary. To put it all together, the SRU consensus guideline and ACR white paper are easily applied in day-to-day practice for masses that are O-RADS 2 and below. An invited commentary by Patel is available online. The online slide presentation from the RSNA Annual Meeting is available for this article. ^©RSNA, 2022.

Two-Step Strategy for Optimizing the Preoperative Classification of Adnexal Masses in a University Hospital, Using International Ovarian Tumor Analysis Models: Simple Rules and Assessment of Different NEoplasias in the adneXa Model

OBJECTIVES

To evaluate the performance of a two-step strategy compared with the International Ovarian Tumor Analysis (IOTA) - Assessment of Different NEoplasias in the adneXa (ADNEX) model for preoperative classification of adnexal masses.

METHODS

An ambispective diagnostic accuracy study based on ultrasound data collected at one university hospital between 2012 and 2018. Two ultrasonographers classified the adnexal masses using IOTA Simple Rules (first step). Not classifiable masses were evaluated using the IOTA ADNEX model (second step). Also, all masses were classified using the IOTA ADNEX model. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV), positive likelihood ratio (LR+) and negative likelihood ratio (LR-), and receiver operating characteristic (ROC) curve were estimated. A P value of <.05 was used to determine statistical significance.

RESULTS

The study included 548 patients and 606 masses. Patients' median age was 41 years with an interquartile range between 32 and 51 years. In the first step, 89 (14%) masses were not classifiable. In the second step, 55 (61.8%) masses were classified as malignant. Furthermore, for the totality of 606 masses, the IOTA ADNEX model estimated the probability that 126 (20.8%) masses were malignant. The two-step strategy had a sensitivity, specificity, PPV, NPV, LR+, LR-, and ROC curve of 86.8%, 91.01%, 51.9%, 98.4%, 9.7, 0.1, and 0.889, respectively; compared to IOTA ADNEX model that had values of 91.8%, 87.16%, 44.4%, 99%, 7.1, 0.09, and 0.895, respectively.

CONCLUSION

The two-step strategy shows a similar diagnostic performance when compared to the IOTA ADNEX model. The IOTA ADNEX model involves only one step and can be more practical, and thus would be recommended to use.

Accuracy of Magnetic Resonance Imaging for Identifying Ovarian Cancer in a Community-Based Setting

Introduction: Many ovarian or adnexal masses have an indeterminate appearance on ultrasound that can raise concerns about cancer. Although magnetic resonance imaging (MRI) has been reported to reliably distinguish between benign and malignant masses, studies evaluating the accuracy of MRI in community-based practice settings are lacking.

Methods: Women who underwent MRI to further evaluate an ultrasound-detected adnexal mass in 2016–2017 within a large community-based health system were identified. MRI reports were classified as favoring malignancy, benign disease, or indeterminate, blinded to pathological outcome. With a minimum of 2 years of follow-up, all ovarian cancers and borderline tumors were identified, and the accuracy of MRI assessment was determined.

Results: Among 338 women who had MRI to evaluate an adnexal mass, 144 (42.6%) subsequently underwent surgery. MRI favored malignancy in 7 (4.9%) cases, benign disease in 89 (62.2%) cases, and was indeterminate in 48 (33.6%) cases. Of the seven cases in which MRI favored malignancy, two cancers and five benign tumors were found. An additional 10 cases of cancer or borderline tumor were found among women who had MRI reports that were read as indeterminate (n = 6) or that favored benign disease (n = 4). The sensitivity, specificity, positive predictive value, and negative predictive value of an MRI favoring malignancy were 16.7%, 96.2%, 28.5%, and 92.7%, respectively.

Discussion: In a large community-based setting, an MRI favoring malignancy was more likely to be associated with benign disease than cancer and identified only 16.7% of true malignant cases. The findings suggest that the ability of MRI to differentiate between benign and malignant adnexal masses in community-based practice settings is currently limited.

Frequency of potential causes of lower back pain and incidental findings in patients with suspected sacroiliitis: retrospective analysis of 886 patients with negative sacroiliac MRI examination for sacroiliitis

BACKGROUND

In a majority of patients with suspected sacroiliitis (SI) who underwent sacroiliac magnetic resonance imaging (MRI), imaging studies may be normal, may depict other causes for pain, or may show clinically irrelevant incidental findings.

PURPOSE

To determine the prevalence of possible etiologies other than SI and frequency of incidental findings demonstrated on sacroiliac MRI examinations in a cohort of patients with lower back pain and suspected SI.

MATERIAL AND METHODS

Sacroiliac MRI examinations of 1421 patients with suspected SI were retrospectively reviewed. In patients without SI findings, other potential causes for lower back pain and incidental findings were documented.

RESULTS

SI was present in 535 of 1421 patients (37.6%). In 886 of the patients whose MRI studies were negative for SI, other possible causes for lower back pain or incidental findings were seen in 386 (43.5%). The most common musculoskeletal (MSK) finding was lumbosacral transitional vertebra (8.6%) followed by findings suggesting piriformis syndrome (4.2%), spondylosis (3.7%), and sacral insufficiency fractures (1.8%). The most common non-MSK findings were follicular cysts (15.3%) and uterine fibroids (4.9%).

CONCLUSION

In patients with suspected SI but negative MRI examinations for SI, some other possible causes for lower back pain and several incidental findings can be seen on imaging. The presence of these findings may explain the patient's symptoms, and awareness of these conditions may be helpful in patient management and individualizing treatment.

Growth Rate of Ovarian Serous Cystadenomas and Cystadenofibromas

OBJECTIVES

We analyzed growth rates of benign ovarian serous cystadenomas and cystadenofibromas to understand what percentage would show a volume doubling time (DT) of less than 3 years, between 3 and 5 years, or greater than 5 years.

METHODS

We retrospectively reviewed pathology records (January 1, 2014, to June 30, 2019) to find all surgically excised ovarian serous cystadenomas and cystadenofibromas. Imaging records were then reviewed to identify those that had been confidently identified with ultrasound imaging, magnetic resonance imaging, or computed tomography at least twice before surgical removal, with at least a 60-day interval between studies. Three orthogonal measurements were recorded on the first and last imaging studies on which the mass was detected, with volume calculations by the prolate formula (product of 3 measurements multiplied by 0.52). The volume DT was calculated and grouped into 1 of 5 categories: (1) DT of less than 1 year; (2) DT of 1 to 3 years; (3) DT of 3 to 5 years; (4) DT of 5 to 10 years; and (5) no growth (any mass with a DT >10 years or showing a decrease in volume).

RESULTS

A total of 102 of 536 cystadenomas and 44 of 227 cystadenofibromas met inclusion criteria. Of the 146 tumors, 40 (27.4%) had a DT of less than 1 year; 38 (26.0%) had a DT of 1 to 3 years; 22 (15.1%) had a DT of 3 to 5 years; 10 (6.8%) had a DT of 5 to 10 years; and 36 (24.7%) showed no growth.

CONCLUSIONS

A total of 53.4% of ovarian serous cystadenomas/cystadenofibromas have a DT of less than 3 years; 15.1% have a DT between 3 and 5 years; and 31.5% have a DT of greater than 5 years or show no growth.

The use of different doses levonorgestrel-releasing intrauterine system (LNG-IUS): real-world data from a multicenter Italian study

PURPOSE

Current research fails to adequately inform about the differential use of available levonorgestrel-releasing intrauterine systems (LNG-IUSs) in real life. Aim of our study was to compare the characteristics, satisfaction, continuation rates, and adverse effects between users of the high-dose LNG-IUS (52 mg) and of the low dose LNG-IUS (13.5 mg and 19.5 mg).

MATERIALS AND METHODS

A prospective cohort study was performed in two Services for Family Planning in normal menstruating women with the inclusion of all new prescriptions of LNG-IUS for contraception. Women were followed for a mean of 9.1 ± 2.6 months after placement.

RESULTS

109 women (mean age of 39.8 ± 8.7 years old) were included, 69.7% using a high dose LNG-IUS and 30.3% using a low dose LNG-IUS. Women with a low dose LNG-IUS were significantly younger, thinner, more nulliparous, with fewer vaginal deliveries and C-sections, with a lower menstrual flow length and with more previous use of short-acting reversible contraceptives (p < 0.05). LNG-IUS continuation was similar and very high at the last follow-up: 100 vs. 94.7% in the low and high dose LNG-IUS groups, respectively (p = 0.18). Satisfaction with treatment at the end of the study was similar between different LNG-IUS doses (p = 0.85), with 78.9% being satisfied/very satisfied. Bleeding patterns were significantly different between the two LNG-IUS doses (p < 0.0001). Diagnosis of dysfunctional cysts was more frequent in women with high dose compared to low dose LNG-IUS (22.2 vs. 12.1%), albeit not significantly.

CONCLUSIONS

We have shown a clear differential use of available LNG-IUS in clinical practice, both as baseline characteristics and as different outcomes, primarily for bleeding patterns. However, all these systems were associated with a very high rate of satisfaction and continuation.

Incidental Ovarian and Uterine Findings on Cross-sectional Imaging

Incidental adnexal masses and uterine findings occur with a high frequency on cross-sectional imaging examinations, particularly in postmenopausal women in whom imaging is performed for a different reason. These incidentalomas encompass a gamut of potential pelvic gynecologic disorders. Most are benign ovarian cysts; however, other less commonly encountered disorders and improperly positioned gynecologic devices may be seen. A knowledge of the management recommendations for such pelvic incidental findings is critical to avoid unnecessary imaging and surgical interventions, as well as to avoid failure in diagnosis and management of some of these conditions.

Decoding incidental ovarian lesions: use of texture analysis and machine learning for characterization and detection of malignancy

PURPOSE

To compare CT texture features of benign and malignant ovarian lesions and to build a machine learning model to detect malignancy in incidental ovarian lesions.

METHODS

In this IRB-approved, HIPAA-compliant, retrospective study, 427 consecutive patients with incidental ovarian lesions detected on contrast-enhanced CT (348, 81.5% benign and 79, 18.5% malignant) were included. The following CT texture features were analyzed using commercially available software (TexRAD, Feedback Plc, Cambridge, UK): total pixel, mean, standard deviation (SD), entropy, mean value of positive pixels (MPP), skewness, kurtosis and entropy. Three machine learning models were created by combining texture features and patients' age, and performance of these models was assessed using tenfold cross-validation. Receiver operating characteristics (ROC) were constructed to assess sensitivity and specificity. The cutoff value was picked using a cost-weighted method.

RESULTS

Total pixels, mean, SD, entropy, MPP, and skewness were significantly different between benign and malignant groups (p < 0.05). With a selected 10 as a cost factor to optimize cutoff value selection, sensitivity 92%, specificity 60% in the random forest (RF) model, sensitivity 91%, specificity 69% in SVM model, and sensitivity 92%, specificity 61% in the logistic regression, respectively.

CONCLUSION

CT texture analysis could provide objective imaging analysis of incidental ovarian lesions and ML models using CT texture features and age demonstrated high sensitivity and moderate specificity for detection of malignant lesions.

Contemporary Guidelines for Adnexal Mass Imaging: A 2020 Update

Incidental adnexal masses are commonly encountered at ultrasound, computed tomography, and magnetic resonance imaging. Since many of these lesions are surgically resected and ultimately found to be benign, patients may be exposed to personal and economic costs related to unnecessary oophorectomy. Thus, accurate non-invasive risk stratification of adnexal masses is essential for optimal management and outcomes. Multiple consensus guidelines in radiology have been published to assist in characterization of these masses as benign, indeterminate, or likely malignant. In the last two years, several new and updated stratification systems for assessment of incidental adnexal masses have been published. The purpose of this article is to offer a concise review of four recent publications: ACR 2020 update on the management of incidental adnexal findings on CT and MRI, SRU 2019 consensus update on simple adnexal cysts, O-RADS ultrasound risk stratification system (2020), and O-RADS MRI risk stratification system (2020).

Pitfalls in Renal Ultrasound

Ultrasound (US) is replete with pitfalls in technique and interpretation, and renal imaging is no exception. Because US of the kidneys is a very common initial and follow-up imaging examination, it is important to be aware of both common and unusual sources of potential error. This essay will review optimal technique and discuss common overcalls, under calls, and misinterpretations with respect to renal size, hydronephrosis, calculi, cysts, masses, and collections.

Surveillance in Older Women With Incidental Ovarian Cysts: Maximal Projected Benefits by Age and Comorbidity Level

PURPOSE

The aim of this study was to estimate effects on life expectancy (LE) of imaging-based ovarian surveillance after detection of incidental postmenopausal ovarian cysts, under different assumptions of patient age, comorbidity level, and cancer risk and detection.

METHODS

A decision-analytic Markov model was developed to estimate LE benefits. Hypothetical cohorts of postmenopausal women with simple ovarian cysts were evaluated, with varied age (66-80 years) and comorbidity level (none, mild, moderate, severe). For each cohort, imaging "follow-up" (2 years) and "no-follow-up" strategies were compared. Consistent with current evidence, increased cancer risk in patients with cysts was not assumed; however, incident ovarian cancers could be detected during follow-up. To estimate theoretical maximal LE gains from follow-up, perfect ovarian cancer detection and treatment during follow-up were assumed. This and other key assumptions were varied in sensitivity analysis.

RESULTS

Projected LE gains from follow-up were limited. For 66-, 70-, 75-, and 80-year-old women with no comorbidities, LE gains were 5.1, 5.1, 4.5, and 3.7 days; with severe comorbidities, they were 3.5, 3.2, 2.7, and 2.1 days. With sensitivity of 50% for cancer detection, they were 3.7 days for 66-year-old women with no comorbidities and 1.3 days for 80-year-old women with severe comorbidities. When cancer risk for women with cysts was assumed to be elevated (1.1 times average risk), LE gains increased only modestly (5.6 and 2.3 days for analogous cohorts).

CONCLUSIONS

Even in the circumstance of perfect ovarian cancer detection and treatment, surveillance of postmenopausal women (≥66 years of age) with simple cysts affords limited benefits, particularly in women with advanced age and comorbidities.

Mapping the Ultrasound Landscape to Define Point-of-Care Ultrasound and Diagnostic Ultrasound: A Proposal From the Society of Radiologists in Ultrasound and ACR Commission on Ultrasound

Current descriptions of ultrasound evaluations, including use of the term "point-of-care ultrasound" (POCUS), are imprecise because they are predicated on distinctions based on the device used to obtain images, the location where the images were obtained, the provider who obtained the images, or the focus of the examination. This is confusing because it does not account for more meaningful distinctions based on the setting, comprehensiveness, and completeness of the evaluation. In this article, the Society of Radiologists in Ultrasound and the members of the American College of Radiology Ultrasound Commission articulate a map of the ultrasound landscape that divides sonographic evaluations into four distinct categories on the basis of setting, comprehensiveness, and completeness. Details of this classification scheme are elaborated, including important clarifications regarding what ensures comprehensiveness and completeness. Practical implications of this framework for future research and reimbursement paradigms are highlighted.

Interpreting body MRI cases: classic findings in pelvic MRI

The high contrast resolution provided by magnetic resonance imaging (MRI) compared to all other modalities allows the interpreting radiologist to make a specific diagnosis for many common and uncommon findings. In some cases, the diagnosis can be so certain that there is no differential diagnosis. In this article, we review the most classically recognized findings when interpreting MRI of the pelvis including the following: Ovaries: Simple cyst, hemorrhagic cyst, corpus luteum, dermoid, fibroma/fibrothecoma. Uterus: C-section scar, adenomyosis, endometriosis, fibroid, congenital uterine anomalies. Cervix: nabothian cyst, cervical cancer. Vagina/Vulva: Gardener's duct cyst, Bartholin's gland cyst. Urethra: skene gland cyst, urethral diverticulum. Prostate: utricle cyst, Mullerian duct cyst, benign prostatic hyperplasia, prostate cancer.

Imaging of Benign Adnexal Disease

This article provides an overview of the imaging evaluation of benign ovarian and adnexal masses in premenopausal and postmenopausal women and lesions discovered during pregnancy. Current imaging techniques are discussed, including pitfalls and differential diagnosis when necessary, as well as management. It also reviews the now well-established American College of Radiology (ACR)/Society of Radiologists in Ultrasound consensus guidelines and covers the more recently introduced Ovarian-Adnexal Reporting and Data System by the ACR and the recently published ADNEx Scoring System.