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.

Single-cell transcriptomics is revolutionizing the improvement of plant biotechnology research: recent advances and future opportunities.

Single-cell approaches are a promising way to obtain high-resolution transcriptomics data and have the potential to revolutionize the study of plant growth and development. Recent years have seen the advent of unprecedented technological advances in the field of plant biology to study the transcriptional information of individual cells by single-cell RNA sequencing (scRNA-seq). This review focuses on the modern advancements of single-cell transcriptomics in plants over the past few years. In addition, it also offers a new insight of how these emerging methods will expedite advance research in plant biotechnology in the near future. Lastly, the various technological hurdles and inherent limitations of single-cell technology that need to be conquered to develop such outstanding possible knowledge gain is critically analyzed and discussed.

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.

Adnexal Lesion Imaging: Past, Present, and Future.

Currently, imaging is part of the standard of care for patients with adnexal lesions prior to definitive management. Imaging can identify a physiologic finding or classic benign lesion that can be followed up conservatively. When one of these entities is not present, imaging is used to determine the probability of ovarian cancer prior to surgical consultation. Since the inclusion of imaging in the evaluation of adnexal lesions in the 1970s, the rate of surgery for benign lesions has decreased. More recently, data-driven Ovarian-Adnexal Reporting and Data System (O-RADS) scoring systems for US and MRI with standardized lexicons have been developed to allow for assignment of a cancer risk score, with the goal of further decreasing unnecessary interventions while expediting the care of patients with ovarian cancer. US is used as the initial modality for the assessment of adnexal lesions, while MRI is used when there is a clinical need for increased specificity and positive predictive value for the diagnosis of cancer. This article will review how the treatment of adnexal lesions has changed due to imaging over the decades; the current data supporting the use of US, CT, and MRI to determine the likelihood of cancer; and future directions of adnexal imaging for the early detection of ovarian cancer.

Assessment of Amniotic Fluid Volume in Pregnancy.

Amniotic fluid (AF) is an integral part of the fetal environment and is essential for fetal growth and development. Pathways of AF recirculation include the fetal lungs, swallowing, absorption through the fetal gastrointestinal tract, excretion through fetal urine production, and movement. In addition to being a marker for fetal health, adequate AF is necessary for fetal lung development, growth, and movement. The role of diagnostic imaging is to provide a detailed fetal survey, placental evaluation, and clinical correlation with maternal conditions to help identify causes of AF abnormalities and thereby enable specific therapy. Oligohydramnios prompts evaluation for fetal growth restriction as well as genitourinary issues, including renal agenesis, multicystic dysplastic kidneys, ureteropelvic junction obstruction, and bladder outlet obstruction. Premature preterm rupture of membranes should also be clinically excluded as a cause of oligohydramnios. Clinical trials evaluating amnioinfusion are underway as a potential intervention for renal causes of oligohydramnios. Most cases of polyhydramnios are idiopathic, with maternal diabetes being a common cause. Polyhydramnios prompts evaluation for fetal gastrointestinal obstruction and oropharyngeal or thoracic masses, as well as neurologic or musculoskeletal anomalies. Amnioreduction is performed only for maternal indications such as symptomatic polyhydramnios causing maternal respiratory distress. Polyhydramnios with fetal growth restriction is paradoxical and can occur with maternal diabetes and hypertension. When these maternal conditions are absent, this raises concern for aneuploidy. The authors describe the pathways of AF production and circulation, US and MRI assessment of AF, disease-specific disruption of AF pathways, and an algorithmic approach to AF abnormalities. ©RSNA, 2023 Online supplemental material is available for this article. Quiz questions for this article are available through the Online Learning Center.

Morphological control for high proton conduction in robust Co3O4-diethylmethylamine (metal-organic framework) membrane.

Metal-organic framework (MOF) based proton conductors are synthesized by the Avrami model (time-temperature modalities). Our objective here is to obtain a material with high proton conductivity in anhydrous conditions, improved catalytic behaviour and morphology control of conductivity, band gap and catalysis. For this purpose, we try to understand the role of morphology on mass transportation using computational fluid dynamics and the experimental realisation using the synthesis of MOF membranes with high protonic conductivity. In order to alter the morphology, the membranes are synthesized from protic ionic liquid (dimethyl ethyl amine H2PO4) and metal ion (Co3O4) at different temperatures and duration. A high protonic conductivity of 0.0286 S cm-1 with a high transference number >0.99 is observed in anhydrous conditions with the change in morphology. Furthermore, catalyst properties along with high activity (Tafel slope = 39 mV decade-1) with the alteration in morphology are also investigated in detail and observed adsorption governed conduction. This adsorption governed conduction is verified using computational fluid dynamics simulations with the alteration in morphology. This study suggests that morphology not only plays a pivotal role in obtaining a robust proton exchange membrane, it also improves the catalytic functionality and stability of the membrane.

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.

O-RADS MRI Risk Stratification System: Guide for Assessing Adnexal Lesions from the ACR O-RADS Committee.

MRI plays an important role as a secondary test or problem-solving modality in the evaluation of adnexal lesions depicted at US. MRI has increased specificity compared with US, decreasing the number of false-positive diagnoses for malignancy and thereby avoiding unnecessary or over-extensive surgery in patients with benign lesions or borderline tumors, while women with possible malignancies can be expeditiously referred for oncologic surgical evaluation. The Ovarian-Adnexal Reporting and Data System (O-RADS) MRI Committee is an international collaborative effort formed under the direction of the American College of Radiology and includes a diverse group of experts on adnexal imaging and management who developed the O-RADS MRI risk stratification system. This scoring system assigns a probability of malignancy based on the MRI features of an adnexal lesion and provides information to facilitate optimal patient management. The widespread implementation of a codified reporting system will lead to improved interpretation agreement and standardized communication between radiologists and referring physicians. In addition, it will allow for high-quality multi-institutional collaborations-an important unmet need that has hampered the performance of high-quality research in this area in the past. This article provides guidelines on using the O-RADS MRI risk stratification system in clinical practice, as well as in the educational and research settings.

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.

Ovarian cancer reporting lexicon for computed tomography (CT) and magnetic resonance (MR) imaging developed by the SAR Uterine and Ovarian Cancer Disease-Focused Panel and the ESUR Female Pelvic Imaging Working Group.

OBJECTIVES: Imaging evaluation is an essential part of treatment planning for patients with ovarian cancer. Variation in the terminology used for describing ovarian cancer on computed tomography (CT) and magnetic resonance (MR) imaging can lead to ambiguity and inconsistency in clinical radiology reports. The aim of this collaborative project between Society of Abdominal Radiology (SAR) Uterine and Ovarian Cancer (UOC) Disease-focused Panel (DFP) and the European Society of Uroradiology (ESUR) Female Pelvic Imaging (FPI) Working Group was to develop an ovarian cancer reporting lexicon for CT and MR imaging. METHODS: Twenty-one members of the SAR UOC DFP and ESUR FPI working group, one radiology clinical fellow, and two gynecologic oncology surgeons formed the Ovarian Cancer Reporting Lexicon Committee. Two attending radiologist members of the committee prepared a preliminary list of imaging terms that was sent as an online survey to 173 radiologists and gynecologic oncologic physicians, of whom 67 responded to the survey. The committee reviewed these responses to create a final consensus list of lexicon terms. RESULTS: An ovarian cancer reporting lexicon was created for CT and MR Imaging. This consensus-based lexicon has 6 major categories of terms: general, adnexal lesion-specific, peritoneal carcinomatosis-specific, lymph node-specific, metastatic disease -specific, and fluid-specific. CONCLUSIONS: This lexicon for CT and MR imaging evaluation of ovarian cancer patients has the capacity to improve the clarity and consistency of reporting disease sites seen on imaging. KEY POINTS: • This reporting lexicon for CT and MR imaging provides a list of consensus-based, standardized terms and definitions for reporting sites of ovarian cancer on imaging at initial diagnosis or follow-up. • Use of standardized terms and morphologic imaging descriptors can help improve interdisciplinary communication of disease extent and facilitate optimal patient management. • The radiologists should identify and communicate areas of disease, including difficult to resect or potentially unresectable disease that may limit the ability to achieve optimal resection.

Neuroradiology in Transgender Care: Facial Feminization, Laryngeal Surgery, and Beyond.

Transgender individuals experience incongruence between their gender identity and the sex assigned to them at birth. This incongruence can cause many transgender individuals to experience distressing physical and mental discord, a diagnosis known as gender dysphoria. Craniofacial structures have distinct anthropometric characteristics that affect perceived masculinity and femininity. The face, neck, and voice are highly exposed anatomic areas that have recognizable gender-specific characteristics that may hinder a transgender individual's successful social integration and public acceptance. Reconstructive facial and laryngeal procedures are among the surgical options transgender persons may elect to undergo to better align their physical appearance with their gender identity. These include feminization surgeries such as facial feminization and reduction chondrolaryngoplasty, as well as masculinizing facial and laryngeal surgeries. Maxillofacial CT is frequently used in the preoperative evaluation of patients before facial feminization surgery (FFS). Several CT measurements guide surgeons to the optimal correction required in FFS to achieve appropriate aesthetic planes. Mapping important craniofacial landmarks to avoid untoward surgical complications is crucial. Transgender patients may encounter other neurologic complications that require neuroimaging evaluation. For example, gender-affirming hormone therapy (eg, estrogen and testosterone) may increase the risk of stroke or may influence growth of various hormone-sensitive tumors such as pituitary adenomas. Radiologists may interpret imaging examinations in transgender patients for routine care or for evaluation before and after facial and laryngeal surgeries and must be aware of the role of neuroimaging in the care of this population. An invited commentary by Callen is available online. The online slide presentation from the RSNA Annual Meeting is available for this article. ©RSNA, 2022.

Imaging Cancer in Pregnancy.

Pregnancy-associated cancer (PAC) is defined as cancer that is detected during pregnancy and up to 1 year postpartum. Although rare (~1:1000 pregnancies), PAC is increasing owing to postponed childbearing and advanced maternal age at conception. Cancer-related symptoms masked by physiologic gestational changes may delay diagnosis. Imaging, clinical management, and treatment require a carefully choreographed multidisciplinary team approach. The risk-benefit of every imaging modality, the strategies to balance the safety of mother and fetus, and the support of the patient and family at every step are crucial. US and MRI are preferred imaging modalities that lack ionizing radiation. Radiation dose concerns should be addressed, noting that most imaging examinations (including mammography, radiography, CT, and technetium 99m-labeled sulfur colloid sentinel lymph node staging) are performed at radiation levels below thresholds at which deterministic side effects are seen. Dose estimates should be provided after each examination. The use of iodinated intravenous contrast material is safe during pregnancy, but gadolinium-based contrast material should be avoided. Accurate diagnosis and staging combined with gestational age affect decisions about surgery and chemotherapy. Whole-body MRI with diffusion-weighted sequences is ideal to screen for primary and metastatic sites, determine disease stage, identify biopsy targets, and guide further cancer site-specific imaging. The authors provide an update of the imaging triage, safety considerations, cancer-specific imaging, and treatment options for cancer in pregnancy. An invited commentary by Silverstein and Van Loon is available online. Online supplemental material is available for this article. ©RSNA, 2022.

Sequelae of Eating Disorders at Imaging.

Although eating disorders are common, they tend to be underdiagnosed and undertreated because social stigma tends to make patients less likely to seek medical attention and less compliant with medical treatment. Diagnosis is crucial because these disorders can affect any organ system and are associated with the highest mortality rate of any psychiatric disorder. Because of this, imaging findings, when recognized, can be vital to the diagnosis and management of eating disorders and their related complications. The authors familiarize the radiologist with the pathophysiology and sequelae of eating disorders and provide an overview of the related imaging findings. Some imaging findings associated with eating disorders are nonspecific, and others are subtle. The presence of these findings should alert the radiologist to correlate them with the patient's medical history and laboratory results and the clinical team's findings at the physical examination. The combination of these findings may suggest a diagnosis that might otherwise be missed. Topics addressed include (a) the pathophysiology of eating disorders, (b) the clinical presentation of patients with eating disorders and their medical complications and sequelae, (c) the imaging features associated with common and uncommon sequelae of eating disorders, (d) an overview of management and treatment of eating disorders, and (e) conditions that can mimic eating disorders (eg, substance abuse, medically induced eating disorders, and malnourishment in patients with cancer). Online supplemental material is available for this article. ©RSNA, 2022.

Influence of the crystalline phase on the electrocatalytic behaviour of Sm2-xSrxNiO4-δ (x = 0.4 to 1.0) Ruddlesden-Popper-based systems: a comparative study of bulk and thin electrocatalysts.

Herein, the influence of compositional engineering via active site alternation on catalytic behaviour has been studied for the Ruddlesden-Popper-based system Sm2-xSrxNiO4-δ. A phase change from orthorhombic (x = 0.6) to tetragonal (x = 1.0) in bulk Sm2-xSrxNiO4-δ is confirmed by Rietveld (XRD) analysis, thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS). To alter the active sites, we fabricated thin films for x = 0.6 and x = 1.0 using a pulsed laser deposition technique. The electrocatalytic behaviour has been studied in an environmentally friendly medium, i.e., a neutral medium (pH = 7), for both bulk and thin films, and parameters such as transient response, electrochemical reversibility and oxygen evolution reactivity are measured. The cyclic voltammetry curves suggest that electrochemical reversibility for thin films is governed by adsorption as opposed to the diffusion observed for bulk samples. Our investigation further suggests that moderate electroactivity can be achieved with an increase in active sites on miniaturization with the phase change.

Transvaginal Ultrasound-Guided Fine-Needle Aspiration Biopsy of Pelvic Lesions.

OBJECTIVES: To assess adequacy of transvaginal ultrasound-guided fine-needle aspiration biopsy (TVUS-FNAB) for pathologic diagnosis of pelvic masses performed using onsite cytopathology consultation. METHODS: In this Institutional Review Board approved, Health Insurance Portability and Accountability Act (HIPAA) compliant study, radiology records were retrospectively queried to identify patients who underwent TVUS-FNAB of a pelvic mass over a 11-year duration. TVUS-FNAB adequacy was determined by correlating cytopathology results with transvaginal ultrasound-guided core-needle biopsy (TVUS-CNB) or surgical pathology results when available, and with clinical diagnostic confidence when additional pathology confirmation was not available. Secondary analysis included patient age, history of hysterectomy, or pelvic malignancy. Target-specific features analyzed included mass size, depth, location, and final pathologic diagnosis. RESULTS: Sixty patients underwent TVUS-FNAB of pelvic masses, 43 of which underwent FNAB only and 17 underwent both TVUS-FNAB and TVUS-CNB during the same procedure. TVUS-FNAB alone was adequate for diagnosis in 51 (85%) cases and addition of core-needle biopsy (CNB) achieved a diagnosis in additional 4 patients, increasing overall diagnostic accuracy to 92% (55/60). FNAB inadequacy had statistically significant association with increasing mass depth, occurrence of a minor intraprocedural complication, and decision to perform a CNB (P <.05). Number of FNAB passes, mass size, history of hysterectomy, and final diagnosis were not statistically significant predictors of FNAB adequacy. CONCLUSION: TVUS-FNAB has a high specimen adequacy rate when performed with an onsite cytopathologist and can be considered first-line approach for image-guided sampling of pelvic lesions with option to add CNB if preliminary cytopathologic review does not confirm sample adequacy.

Ultrasound characteristics of early-stage high-grade serous ovarian cancer.

BACKGROUND: Survival from ovarian cancer is strongly dependent on the stage at diagnosis. Therefore, when confronted with a woman with an isolated adnexal mass, clinicians worry about missing the opportunity to detect cancer at an early stage. High-grade serous ovarian cancers account for 80% of ovarian cancer deaths, largely because of their tendency to be diagnosed at a late stage. Among adnexal masses, large size and the presence of solid areas on ultrasound examination have been found to be associated with cancer, but it is unclear whether these characteristics identify early-stage cases. OBJECTIVE: This study aimed to evaluate the ultrasound findings associated with clinically detected early-stage high-grade serous ovarian cancer. STUDY DESIGN: This was a retrospective cohort study of women diagnosed with stage I or II high-grade serous ovarian or fallopian tube cancer measuring at least 1 cm at pathology from 2007 to 2017. Preoperative ultrasound examinations were independently reviewed by 3 radiologists. Adnexal masses were scored for size and volume; overall appearance; presence, thickness, and vascularity of septations; morphology and vascularity of other solid components; and degree of ascites. Characteristics were compared between masses of <5 cm and larger masses and between stage I and stage II cases. Interobserver variability was assessed. RESULTS: Among 111 women identified, 4 had bilateral ovarian involvement, for a total of 115 adnexal masses characterized by ultrasound examination. The mean age at diagnosis was 61.8 years (range, 42-91 years). The median mass size was 9.6 cm (range, 2.2-23.6 cm) with 87% of cases having a mass size of ≥5 cm. A mixed cystic and solid appearance was most common (77.4%), but a completely solid appearance was more frequently seen for tumors of <5 cm compared with larger tumors (26.7% vs 13.0%). Solid components other than septations were seen in 97.4% of cases. The characteristics of stage I and II cases were similar other than ascites, which was more commonly seen in stage II cases (18.0% vs 3.1%, respectively). Interobserver concordance was high for size and volume measurements (correlation coefficients, 0.96-0.99), with moderate agreement observed across the other ultrasound characteristics (Fleiss kappa, 0.45-0.58). CONCLUSION: In this community-based cohort, early-stage high-grade serous cancers rarely presented as masses of <5 cm or masses without solid components other than septations. Our findings provide additional support for the observation of small masses without solid areas on ultrasound examination.

Role of Ultrasound and MRI in Diagnosis of Severe Placenta Accreta Spectrum Disorder: An Intraindividual Assessment With Emphasis on Placental Bulge.

BACKGROUND. The "placental bulge" sign (focal area of myometrial-placental bulging beyond the normal uterine contour) on ultrasound (US) or MRI is postulated to represent deeper venous invasion in placenta accreta spectrum (PAS) disorder and may represent severe PAS. OBJECTIVE. The purpose of this study was to evaluate the diagnostic performance and interobserver agreement of US and MRI features for diagnosis of severe PAS, with an emphasis on the placental bulge sign. METHODS. This retrospective study included 62 pregnant women (mean age, 33.2 ± 5.5 [SD] years) with clinically suspected PAS who underwent both US and MRI. Five readers (two maternal-fetal medicine specialists for US, three abdominal radiologists for MRI) independently reviewed images for the given modality, blinded to the final diagnosis, and recorded the presence of a range of findings (nine on US, eight on MRI), including placental bulge. Intraoperative and pathologic findings were used to separate patients into those with and without severe PAS according to International Federation of Gynecology and Obstetrics classification. Diagnostic performance of US and MRI findings for severe PAS was evaluated, multivariable logistic regression was performed, and interob-server agreement was assessed. RESULTS. A total of 58.1% (36/62) of patients had severe PAS. On US, the finding with the highest accuracy for severe PAS was placental bulge (85.5%), which had a sensitivity of 91.7% and specificity of 76.9%. On MRI, the finding with highest accuracy was also placental bulge (90.3%), which had a sensitivity of 94.4% and specificity of 84.6%. In the multivariable regression analysis, placental bulge was an independent predictor of severe PAS on US (odds ratio [OR], 8.94; p = .02) and MRI (OR, 45.67; p = .003). Interobserver agreement analysis showed a kappa value for placental bulge of 0.48 for MRI and 0.40 for US. Given wide 95% CIs, differences among features for a given modality and differences between modalities were not statistically significant. CONCLUSION. The findings suggest a strong performance of placental bulge in diagnosing severe PAS on both US and MRI, with a potentially stronger performance on MRI. Nonetheless, interobserver agreement remains suboptimal for both modalities. CLINICAL IMPACT. Accurate prenatal diagnosis of severe PAS by imaging could help guide maternal counseling and selection of either hysterectomy or uterine-preserving surgery.

O-RADS for Ultrasound: A User's Guide, From the AJR Special Series on Radiology Reporting and Data Systems.

The Ovarian-Adnexal Reporting and Data System (O-RADS) is a lexicon and risk stratification tool designed for the accurate characterization of adnexal lesions and is essential for optimal patient management. O-RADS is a recent addition to the American College of Radiology (ACR) reporting and data systems and consists of ultrasound (US) and MRI arms. Since most ovarian or adnexal lesions are first detected with US, O-RADS US is considered the primary assessment tool. Application of O-RADS US is recommended whenever a nonphysiologic lesion is encountered. Lesion characterization may be streamlined by use of an algorithmic approach focused on relevant features and an abbreviated version of the lexicon. Resources to expedite O-RADS US categorization and determination of a management recommendation include easy online access to the ACR color-coded risk stratification scorecards and an O-RADS US calculator that is available as a smartphone app. Reporting should be concise and include relevant features for risk stratification that adhere to lexicon terminology. Technical considerations include optimization of gray-scale and color Doppler technique and performance of problem-solving maneuvers to help avoid common pitfalls. This review provides a user-friendly summary of O-RADS US with practical tips for everyday clinical use.

Role of Imaging in Obstetric Interventions: Criteria, Considerations, and Complications.

US has an established role in the prenatal detection of congenital and developmental disorders. Many pregnant women undergo US at 18-20 weeks of gestation for assessment of fetal anatomy and detection of structural anomalies. With advances in fetoscopy and minimally invasive procedures, in utero fetal interventions can be offered to address some of the detected structural and physiologic fetal abnormalities. Most interventions are reserved for conditions that, if left untreated, often cause in utero death or a substantially compromised neonatal outcome. US is crucial for preprocedural evaluation and planning, real-time procedural guidance, and monitoring and assessment of postprocedural complications. Percutaneous needle-based interventions include in utero transfusion, thoracentesis and placement of a thoracoamniotic shunt, vesicocentesis and placement of a vesicoamniotic shunt, and aortic valvuloplasty. Fetoscopic interventions include myelomeningocele repair and tracheal balloon occlusion for congenital diaphragmatic hernia. In rare cases, open hysterotomy may be required for repair of a myelomeningocele or resection of a sacrococcygeal teratoma. Monochorionic twin pregnancies involve specific complications such as twin-twin transfusion syndrome, which is treated with fetoscopic laser ablation of vascular connections, and twin reversed arterial perfusion sequence, which is treated with radiofrequency ablation. Finally, when extended placental support is necessary at delivery for repair of congenital high airway obstruction or resection of lung masses, ex utero intrapartum treatment can be planned. Radiologists should be aware of the congenital anomalies that are amenable to in utero interventions and, when necessary, consider referral to centers where such treatments are offered. Online supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article. ©RSNA, 2021.

US-guided Interventions to Diagnose and Treat Gynecologic and First-Trimester Disease.

US-guided procedures have an essential role in the diagnosis and treatment of multiple obstetric and gynecologic conditions, can be performed with either transvaginal or transabdominal approaches, and include biopsy of masses, aspiration of fluid collections, injection of therapeutic materials, and saline-infused sonohysterography and hysterosalpingo contrast-enhanced sonography. The full digital presentation is available online. ©RSNA, 2021.