O-RADS Ultrasound Version 1: A Scenario-Based Review of Implementation Challenges.

The Ovarian-Adnexal Reporting and Data System (O-RADS) ultrasound (US) risk stratification and management system was first published by the American College of Radiology in 2020. It provides standardized terminology for evaluation of ovarian and adnexal masses, aids risk stratification, and provides management guidelines for different categories of lesions. This system has been validated by subsequent research and found to be a useful diagnostic and management tool. However, as noted in the system's governing concepts, in some clinical scenarios, such as patients with acute symptoms or with a history of ovarian malignancy, O-RADS US does not apply, or the system's standard management may be adjusted. Additional scenarios, such as an adnexal mass in pregnancy, present challenges in the application of O-RADS US to assist diagnosis and management. The purpose of this article is to highlight 10 clinical scenarios in which O-RADS US version 1 may not apply, may be difficult to apply, or may require modified management. Additional scenarios in which O-RADS US can be appropriately applied are also described.

Role of Sonographic Characteristics of Thyroid Bed Lesions Identified Following Thyroidectomy in the Diagnosis or Exclusion of Recurrent Cancer.

Background US of the thyroid bed in patients with thyroid cancer often depicts small lesions, but it is unclear whether US characteristics of lesions can help predict cancer recurrence. Purpose To determine whether size or US features of lesions in the thyroid bed after thyroidectomy in conjunction with clinical features can help predict thyroid cancer recurrence. Materials and Methods With use of a US reporting database, all patients imaged between July 2006 and June 2016 with an indication of post-thyroidectomy follow-up were retrospectively identified. Recorded data included patient demographic characteristics; date of thyroidectomy; thyroid cancer type; presence, size, and US characteristics of thyroid bed lesions; and results of fine-needle aspiration (FNA). Images were reviewed for lesions that underwent FNA. The Fisher exact test was used for analysis. Results A total of 1885 patients (mean age ± standard deviation, 48 years ± 15; 1493 female patients) underwent 5732 US examinations. Most patients (1541 of 1885 [82%]) had papillary cancer. Overall, 3163 thyroid bed lesions were reported in 5732 US examinations (40.4%). More than half of these lesions (1860 of 3163 [58.8%]) had a maximum measurement of 6 mm or greater. FNA was performed in 144 of the 3163 lesions (4.6%), of which 61 (42.4%) were malignant, 33 (22.9%) were benign, and 50 (34.7%) were nondiagnostic. Five nondiagnostic lesions eventually proved malignant. Only the presence of punctate echogenicities in the lesion (28 of 61 malignant lesions [45.9%]; three of 33 benign lesions [9%]; 12 of 50 nondiagnostic lesions [24%]; P < .001) or the history of positive lymph nodes at thyroidectomy (44 of 61 malignant lesions [72.1%]; 10 of 33 benign lesions [30%]; 19 of 50 nondiagnostic lesions [38%]; P < .001) were associated with malignancy. Of 3019 thyroid bed lesions that did not undergo FNA, three were malignant and 2248 showed no growth at follow-up US ranging from 6 months to 10 years and are presumed benign. Of the 1303 lesions smaller than 6 mm, only two (0.2%) were malignant. Conclusion Small lesions are commonly found in the thyroid bed after thyroidectomy, and most are likely to be benign. Lesions smaller than 6 mm with no punctate echogenicities had a minimal risk for malignancy. © RSNA, 2021 See also the editorial by Grant and Malhi in this issue.

Clinical Significance of Renal Allograft Urothelial Thickening Identified by Ultrasound.

OBJECTIVES: To assess the etiology and clinical implications of ultrasound (US)-diagnosed urothelial thickening (UT) in renal transplants. METHODS: Patients with renal transplants who had UT diagnosed by US from January 2000 to December 2018 were retrospectively identified and compared to patients with transplants without UT scanned during the study period. Medical records were reviewed for demographics, US findings, pathologic results, laboratory values, and clinical outcomes and compared between groups by Fisher exact and t tests. RESULTS: A total of 143 patients with UT and 128 controls comprised our cohorts. The patient age in the UT group versus controls (mean ± SD, 50.2 ± 16.5 versus 51.2 ± 15.3 years) and the time since transplant (2.9 ± 4.2 versus 2.4 ± 5.8 years) were similar. Patients with UT were more likely to be female than controls (76 of 143 [53.1%] versus 53 of 128 [41.4%]; P = .07), but the difference was not statistically significant, and patients with UT were more likely to have indwelling stents (31 of 143 [21.7%] versus 9 of 128 [7.0%]; P = .001) and hydronephrosis (25 of 143 [17.4%] versus 11 of 128 [8.6%]; P = .03). At biopsy, rejection and vascular sclerosis were more likely in patients with UT compared to controls (24 of 25 [49.0%] versus 11 of 43 [25.6%]; P = .031; 42 of 49 [85.7%] versus 22 of 43 [51.2%]; P = .0005, respectively), whereas acute tubular necrosis was similar. The sensitivity (50.0%) and specificity (74.4%) of UT for rejection were low. CONCLUSIONS: Urothelial thickening correlates with US findings of urinary obstruction and indwelling stents, suggesting a possible mechanical component to UT's etiology. Although transplant rejection and vascular sclerosis were more frequent at biopsy in the UT group than controls, UT had low sensitivity and specificity for rejection.

Assessment of American College of Radiology Thyroid Imaging Reporting and Data System (TI-RADS) for Pediatric Thyroid Nodules.

Background The American College of Radiology (ACR) Thyroid Imaging Reporting and Data System (TI-RADS) is a recognized tool for management of thyroid nodules in adults but has not been validated in pediatric patients. Purpose To assess the performance of the ACR TI-RADS criteria for guiding decisions on whether to biopsy thyroid nodules in pediatric patients in a single referral center. Materials and Methods In this retrospective study, a database of thyroid nodules in patients younger than 19 years who underwent fine-needle aspiration (FNA) biopsy between January 2004 and July 2017 was analyzed. ACR TI-RADS criteria were applied to each nodule, and an ACR TI-RADS score was created to determine how the nodule would be managed. The number of nodules that would be biopsied with FNA on the basis of ACR TI-RADS was compared with the total number of nodules biopsied with FNA in this clinic to determine if the use of ACR TI-RADS would have changed the rate of FNA (eg, decreased the number of procedures) and whether that change would have affected the timely diagnosis of cancer. Results A total of 314 patients (mean age, 14.9 years; age range, 2-18 years; 28 prepubertal patients; 286 postpubertal patients; 260 female patients) were evaluated. In these 314 patients, 404 thyroid nodules were scored, of which 19.1% (77 of 404) were malignant. Most cancers were papillary carcinoma (68 [88.3%] of 77). The use of ACR TI-RADS criteria for management of nodules in this pediatric study sample would have resulted in 17 (22.1%) of 77 cancers being missed at the patient's initial visit. Conclusion Use of the current American College of Radiology Thyroid Imaging Reporting and Data System criteria for management of pediatric thyroid nodules is inadequate because a high percentage of cancers would be missed at the initial encounter. © RSNA, 2019.

O-RADS US Risk Stratification and Management System: A Consensus Guideline from the ACR Ovarian-Adnexal Reporting and Data System Committee.

The Ovarian-Adnexal Reporting and Data System (O-RADS) US risk stratification and management system is designed to provide consistent interpretations, to decrease or eliminate ambiguity in US reports resulting in a higher probability of accuracy in assigning risk of malignancy to ovarian and other adnexal masses, and to provide a management recommendation for each risk category. It was developed by an international multidisciplinary committee sponsored by the American College of Radiology and applies the standardized reporting tool for US based on the 2018 published lexicon of the O-RADS US working group. For risk stratification, the O-RADS US system recommends six categories (O-RADS 0-5), incorporating the range of normal to high risk of malignancy. This unique system represents a collaboration between the pattern-based approach commonly used in North America and the widely used, European-based, algorithmic-style International Ovarian Tumor Analysis (IOTA) Assessment of Different Neoplasias in the Adnexa model system, a risk prediction model that has undergone successful prospective and external validation. The pattern approach relies on a subgroup of the most predictive descriptors in the lexicon based on a retrospective review of evidence prospectively obtained in the IOTA phase 1-3 prospective studies and other supporting studies that assist in differentiating management schemes in a variety of almost certainly benign lesions. With O-RADS US working group consensus, guidelines for management in the different risk categories are proposed. Both systems have been stratified to reach the same risk categories and management strategies regardless of which is initially used. At this time, O-RADS US is the only lexicon and classification system that encompasses all risk categories with their associated management schemes.

Thyroid Nodules in Pediatric Patients: Sonographic Characteristics and Likelihood of Cancer.

Purpose To determine the relationship between demographic and sonographic characteristics of thyroid nodules and malignancy in a pediatric population. Materials and Methods All thyroid nodules in patients younger than 19 years that underwent ultrasound (US)-guided fine-needle aspiration biopsy between January 2004 and July 2017 were retrospectively identified. Age, sex, and background appearance of the thyroid gland were recorded for each patient, and sonographic characteristics and pathologic diagnosis were recorded for each nodule. Demographic and sonographic characteristics were assessed to determine which were associated with malignancy. Categorical and continuous variables and interobserver variability were assessed. Results A total of 404 nodules in 314 patients (82.8% female) (age range, 2-18 years; mean age, 14.9 years) were analyzed. A total of 77 nodules (19.1%) were malignant, the majority of which were papillary thyroid carcinoma (n = 68 [88.3%]). The likelihood of malignancy did not differ between boys and girls (27.8% vs 22.7%, P = .64), nor did it differ between prepubertal and pubertal patients (18.8% vs 19.1%, P > .99). The cancer rate in patients with a solitary nodule was higher than that in patients with multiple nodules (29.4% vs 14.2%, P = .003). Sonographic characteristics associated with malignant nodules included larger size, solid parenchyma, taller-than-wide shape, presence of speckled calcifications, lack of a smooth margin, and presence of abnormal lymph nodes. Interobserver variability for assessment of sonographic characteristics ranged from moderate to very strong. Conclusion In children with thyroid nodules, solitary nodules, larger nodule size, solid parenchyma, taller-than-wide shape, speckled calcifications, irregular margins, and abnormal lymph nodes raise concern for malignancy.

Ectopic Intrathyroidal Thymic Tissue Mimicking Thyroid Nodules in Children.

Ectopic intrathyroidal thymic tissue is a benign lesion of nonthyroid origin occasionally found in the pediatric thyroid gland. Accurate diagnosis of such lesions is critical to avoid unnecessary biopsy or surgery. Twelve children referred to our center for the concern of thyroid nodules were found to have intrathyroidal thymic tissue. Most of the lesions had a classic sonographic appearance of a hypoechoic mass with sharp margins and multiple focal internal nonshadowing echogenicities identical to thymic tissue. Sonography and, in select cases, fine-needle aspiration can be used to diagnose benign thymic tissue within the thyroid and avoid unnecessary surgery.

Thyroid hormone inactivation in gastrointestinal stromal tumors.

Gastrointestinal stromal tumors (GISTs) are resistant to traditional chemotherapy but are responsive to the tyrosine kinase inhibitors imatinib and sunitinib. The use of these agents has improved the outcome for patients but is associated with adverse effects, including hypothyroidism. Multiple mechanisms of this effect have been proposed, including decreased iodine organification and glandular capillary regression. Here we report the finding of consumptive hypothyroidism caused by marked overexpression of the thyroid hormone-inactivating enzyme type 3 iodothyronine deiodinase (D3) within the tumor. Affected patients warrant increased monitoring and may require supernormal thyroid hormone supplementation.

Sonographic Appearance of the Gallbladder in the Allogeneic Hematopoietic Stem Cell Transplant Population.

OBJECTIVES: To determine whether gallbladder sonographic findings in hematopoietic stem cell (HSC) transplant patients can distinguish among hepatobiliary complications of HSC transplants (graft-versus-host disease [GVHD] and veno-occlusive disease) and biliary events (cholecystitis, cholangitis, and choledocholithiasis). METHODS: All HSC transplant patients who underwent gallbladder sonography from 2009 through 2012 were identified. Complications and sonographic findings were recorded. RESULTS: Of 124 patients, 66 (53.2%) had an event: 33 (50.0%) had GVHD; 22 (33.3%) had veno-occlusive disease; 6 (9.0%) had a biliary event; 4 (6.0%) had veno-occlusive disease and GVHD; and 1 (1.5%) had veno-occlusive disease and a biliary event. Of all patients, 115 (92.7%) had 1 or more sonographic findings in the gallbladder, with sludge being most common in all groups. In patients with veno-occlusive disease, the second and third most common findings were pericholecystic fluid and wall thickening. In patients with GVHD, distension was the second most common. Patients with biliary events all had distension, and half had pericholecystic fluid. Patients with veno-occlusive disease were significantly more likely to have wall thickening than those with GVHD or no event (77.2% versus 36.3%; P= .005; and 77.2% versus 37.9%; P= .002) and more likely to have pericholecystic fluid than patients with GVHD (95.5% versus 45.5%; P = .0001), a biliary event (95.5% versus 50%; P = .02), or no event (95.5% versus 29.3%; P = .0001). The positive predictive value of any finding was low for all groups because findings were common in patients with no event. CONCLUSIONS: Sonographic abnormalities of the gallbladder after HSC transplants are common in patients with and without HSC transplant complications and in those with biliary events. No sonographic finding is useful to distinguish among complications in HSC transplant patients.

The variable phenotype and low-risk nature of RAS-positive thyroid nodules.

BACKGROUND: Oncogenic mutations are common in thyroid cancers. While the frequently detected RAS-oncogene mutations have been studied for diagnostic use in cytologically indeterminate thyroid nodules, no investigation has studied such mutations in an unselected population of thyroid nodules. No long-term study of RAS-positive thyroid nodules has been performed. METHODS: We performed a prospective, blinded cohort study in 362 consecutive patients presenting with clinically relevant (>1 cm) thyroid nodules. Fine needle aspiration cytology and mutational testing were obtained for all nodules. Post-operative histopathology was obtained for malignant or indeterminate nodules, and benign nodules were sonographically followed. Histopathological features were compared between RAS- and BRAF-positive malignancies. RAS-positive benign nodules were analyzed for growth or cellular change from prior aspirations. RESULTS: Overall, 17 of 362 nodules were RAS-positive. Nine separate nodules were BRAF-positive, of which eight underwent surgery and all proved malignant (100%). Out of the 17 RAS-positive nodules, ten underwent surgery, of which eight proved malignant (47%). All RAS-positive malignancies were low risk - all follicular variants of papillary carcinoma, without extrathyroidal extension, metastases, or lymphovascular invasion. RAS-positivity was associated with malignancy in younger patients (P = 0.028). Of the nine RAS-positive benign nodules, five had long-term prospective sonographic follow-up (mean 8.3 years) showing no growth or signs of malignancy. Four of these nodules also had previous aspirations (mean 5.8 years prior), all with similar benign results. CONCLUSIONS: While RAS-oncogene mutations increase malignancy risk, these data demonstrate a low-risk phenotype for most RAS-positive cancers. Furthermore, cytologically benign, yet RAS-positive nodules behave in an indolent fashion over years. RAS-positivity alone should therefore not dictate clinical decisions.

Sonographic Findings in Fetal Renal Vein Thrombosis.

We present the sonographic findings of fetal renal vein thrombosis in a series of 6 patients. The mean gestational age at diagnosis was 31.2 weeks. Four cases were unilateral, and 2 were bilateral. The most common findings were renal enlargement and intrarenal vascular calcifications, followed by increased renal parenchymal echogenicity. Inferior vena cava thrombosis was found in 4 patients and common iliac vein thrombosis in 2. Fetal renal vein thrombosis is an uncommon diagnosis with characteristic sonographic findings. The presence of these findings should prompt Doppler interrogation of the renal vein and inferior vena cava to confirm the diagnosis.

Sonographic appearance of thyroid cancer in patients with Hashimoto thyroiditis.

OBJECTIVES: To determine whether the sonographic appearance of thyroid cancer differs in patients with and without Hashimoto thyroiditis. METHODS: Patients with histologically proven thyroid cancer who had thyroid peroxidase (TPO) antibodies measured and sonography performed preoperatively were included. We evaluated each nodule for size, echogenicity, composition, margins, halo, and vascularity and evaluated the background heterogeneity of the gland. RESULTS: There were 162 thyroid cancers in 145 patients. Forty-two patients (29.0%) had Hashimoto thyroiditis with positive TPO antibodies, and 103 patients (71.0%) had negative TPO antibodies. The background echogenicity was more often heterogeneous in TPO antibody-positive patients compared to those who had negative TPO antibodies (57.1% versus 26.2%; P= .0005). Comparing cancers in TPO antibody-positive to TPO antibody-negative patients, there was no significant difference in the size, echogenicity, composition, margins, halo presence, calcification presence and type, or vascularity of the cancerous nodule (P > .05). Among TPO antibody-positive patients, comparing thyroid cancerous nodules in patients with heterogeneous glands to those with homogeneous glands, there was no significant difference in any sonographic characteristic except the margin of the nodule, which was more often irregular or poorly defined in heterogeneous glands and more often smooth in homogeneous glands (P< .05). CONCLUSIONS: Sonographic features of thyroid cancer are similar in patients with and without Hashimoto thyroiditis. Among patients with Hashimoto thyroiditis and thyroid cancer, the sonographic appearance of the cancerous nodule is similar, except that cancerous nodule margins are more likely to be irregular or poorly defined when the gland is heterogeneous.

How are childhood thyroid nodules discovered: opportunities for improving early detection.

In a retrospective analysis of childhood thyroid nodules, 18% were radiographic incidentalomas and 41% were discovered by a clinician's palpation; 40% were discovered by patients' families. The latter group had the largest nodules and highest rates of thyroid cancer metastasis, suggesting opportunities for earlier detection through annual well-child visits.

Adnexal sonographic findings in ectopic pregnancy and their correlation with tubal rupture and human chorionic gonadotropin levels.

OBJECTIVES: To determine whether the distribution of transvaginal sonographic findings of ectopic pregnancy has changed since the studies done 20 years ago and to explore the correlation of tubal rupture with transvaginal sonographic findings and human chorionic gonadotropin (hCG) levels. METHODS: Patients with ectopic pregnancy who underwent transvaginal sonography before treatment were included. Sonograms and medical records were retrospectively reviewed. The presence of a tubal ring, the presence of a yolk sac, embryonic cardiac activity, the degree of vascularity on color Doppler imaging, hCG levels, and results of surgery were recorded. RESULTS: Our study included 231 ectopic pregnancies. A positive sonographic adnexal finding was present in 219 cases (94.8%): adnexal mass in 218 (94.4%) and a moderate-to-large amount of free fluid in 84 (36.4%). The adnexal masses were graded as follows: 1, nonspecific mass (125 cases [54.1% of total]); 2, tubal ring without a yolk sac or embryo (57 [24.7%]); 3, yolk sac but no embryonic heartbeat (19 [8.3%]); and 4, embryo with cardiac activity (17 [7.4%]). The mean hCG level increased as the grade ascended from 1 to 4. Thirty-six patients had tubal rupture at surgery within 24 hours of the sonogram. A moderate-to-large amount of free fluid was significantly associated with tubal rupture (P < .05) but had low sensitivity, specificity, and positive predictive value for rupture. Other sonographic findings and hCG levels were not significantly related to tubal rupture. CONCLUSIONS: Transvaginal sonography showed an adnexal abnormality in nearly 95% of our patients with ectopic pregnancy, most commonly a nonspecific adnexal mass. Embryonic cardiac activity was seen in fewer than 10%. Neither sonographic findings nor hCG levels were useful predictors of tubal rupture.

Technical Success and Serious Adverse Events for Fetal Aortic Valvuloplasty in a Large 20-Year Cohort.

Background: FAV is offered to fetuses with severe aortic valve stenosis and evolving hypoplastic left heart syndrome. An inferential analysis of TS and SAE in a large series has not been reported. Objectives: The purpose of this study was to determine factors associated with fetal aortic valvuloplasty (FAV) technical success (TS) and serious adverse events (SAEs). Methods: Retrospective, single-center, cohort analysis of attempted FAV from March 1, 2000, to December 31, 2020. The primary outcome was the TS of FAV, and the secondary outcome was the presence of an SAE. Results: A total of 165 FAVs were attempted in 163 patients with a median gestational age of 24.6 weeks (IQR: 22.9-27.1 weeks). FAV TS was 85% (141/165) and was higher in the 2010 to 2020 era (94% [85/90] vs 75% [56/75]; P < 0.001). Pre-FAV echocardiographic left ventricle (LV) long axis dimension z-score >-0.10 (P < 0.001) and higher LV ejection fraction (P = 0.037) were independently associated with a higher odds of TS. There were 117 SAEs in 67 attempted FAVs (41%), 13 of which were fetal deaths (7.9%). By classification and regression tree analysis, gestational age <21 weeks or in older fetuses, a procedure time of ≥39.6 minutes was associated with higher SAE rate. In the multivariable logistic regression model correcting for gestational age, fetuses with an LV end-diastolic volume <4.09 mL had an age-adjusted OR of 4.71 (95% CI: 1.67-13.29; P = 0.004) for experiencing an SAE. Conclusions: TS of FAV has improved over time, and failure is associated with smaller fetal left heart sizes. SAEs are common and are associated with smaller left hearts and longer procedure times.

Intrauterine fluid with ectopic pregnancy: a reappraisal.

OBJECTIVES: To determine the incidence of intrauterine fluid in patients with ectopic pregnancy and to define the characteristics that distinguish this fluid from an early intrauterine gestational sac. METHODS: We identified all patients scanned transvaginally at our institution from July 2008 through August 2011 for suspected ectopic pregnancy, who proved to have ectopic pregnancy based on pathologic, surgical, or adnexal sonographic findings. We reviewed the sonograms to characterize any fluid in the uterus as to shape, contents, and location. Fluid was classified as type A if it was pointy edged, contained echoes, and/or was clearly located within the uterine cavity or type B if it was smooth walled and anechoic and location was in the decidua or uncertain. The appearance of type A fluid is inconsistent with a gestational sac, while the appearance of type B overlaps that of a gestational sac. RESULTS: Our study population included 229 women with ectopic pregnancy. In 38 (16.6%), sonography showed fluid in the uterus, which was classified as type A in 31 and type B in 7. Only 2 patients (0.9%) had type B fluid with no adnexal findings suggestive of ectopic pregnancy. Based on these results and the published incidence of ectopic pregnancy (2% of all pregnancies), we calculated that a patient with a positive pregnancy test, an intrauterine smooth-walled anechoic cystic structure, and no adnexal mass has a 0.02% probability of ectopic pregnancy, while the probability of intrauterine pregnancy in such a patient is 99.98%. CONCLUSIONS: Fluid can be seen in the uterus in 16.6% of patients with ectopic pregnancy. On transvaginal sonography, it can be distinguished from an early intrauterine gestational sac based on shape, contents, and/or location in most cases. In the remaining cases, the fluid appears indistinguishable from, and is highly likely to represent, an early intrauterine gestation.

Subacute granulomatous (de Quervain) thyroiditis: grayscale and color Doppler sonographic characteristics.

OBJECTIVES: To describe the sonographic characteristics of subacute granulomatous (De Quervain) thyroiditis. METHODS: We retrospectively identified all patients at our institution during the last 11 years who had thyroid sonography with findings suggestive of subacute granulomatous thyroiditis. We then reviewed clinical data and laboratory results to establish the clinical diagnosis. A final diagnosis of subacute granulomatous thyroiditis was made on the basis of clinical symptoms, suppressed thyrotropin, an elevated erythrocyte sedimentation rate, and/or reduced or absent radionuclide uptake while hyperthyroid. RESULTS: Our study population consisted of 35 patients. Twenty-seven patients (79.4%) met clinical criteria for subacute thyroiditis. Symptoms included neck pain in 26 of 27 patients with subacute thyroiditis. The erythrocyte sedimentation rate ranged from 22 to 101 mm/h. In 21 cases (77.8%), sonography revealed focal, poorly defined, nonovoid areas of decreased echogenicity. Findings were bilateral in 16 patients and unilateral in 5. In the remaining 6, the gland or an entire lobe was diffusely heterogeneous. Color Doppler interrogation was performed in 20 patients. Flow was decreased to the sonographically abnormal areas in 19 (95%) and slightly increased in 1 patient. In all 9 patients who underwent radionuclide scanning, focal defects or large areas of decreased or absent uptake were found during the time of suppressed thyrotropin. Enlarged lymph nodes were noted in 16 patients (59.3%). CONCLUSIONS: The positive predictive value of sonography for diagnosing subacute granulomatous thyroiditis is 79.4%. The most common sonographic appearance is poorly defined regions of decreased echogenicity with decreased vascularity in the affected areas.

Use of high-frequency ultrasound guidance for intraoperative zygomatic arch fracture reduction.

Zygomatic arch fractures are common facial fractures; the management depends on the extent of the injury, the displacement of the bone, and coronoid impingement. For fractures without a need for fixation, an intraoral approach, known as Keen, or a temporal hairline approach, known as Gillies, can be used. However, without direct visualization of the fracture line, there is a risk for inadequate reduction. We have therefore begun to use ultrasound assistance to confirm proper reduction. We believe that intraoperative ultrasound guidance can be used to guide the surgeon toward the most precise fracture reduction and present 3 examples from our practice. We recommend the use of ultrasound in the reduction of zygomatic arch fractures.

Interreader Agreement and Intermodality Concordance of O-RADS US and MRI for Assessing Large, Complex Ovarian-Adnexal Cysts.

Purpose To assess interreader agreement of the Ovarian-Adnexal Reporting and Data System (O-RADS) and intermodality concordance between US and MRI for characterizing complex adnexal cysts measuring 5 cm or larger. Materials and Methods This retrospective study included 58 "complex cysts" measuring at least 5 cm in size observed at both US and MRI in 54 women (median age, 37 years ± 12 [SD]; seven postmenopausal women) between July 2017 and June 2020, identified from an electronic US database. A separate set of two blinded radiologists independently reviewed the US or MR images to assign the O-RADS category, and an adjudicator resolved discrepancies (a total of six readers). Lesion outcome (49 benign, eight malignant, one lost to follow-up) was recorded. Interreader agreement of O-RADS US and O-RADS MRI and concordance between US and MRI were analyzed. Results Interreader agreement was fair for US (κ = 0.31), moderate for MRI (κ = 0.43), and moderate between US and MRI (κ = 0.58). A significant positive correlation was found between O-RADS US and MRI (τ = 0.72, P < .001). The O-RADS 4 threshold yielded the highest accuracy for both US and MRI (area under the receiver operating characteristic curve = 0.92 and 0.995, respectively). Considering O-RADS US 4 or 5 as potentially malignant and 1-3 as benign, eight lesions that were assessed as potentially malignant at US were correctly downgraded to benign by using findings at MRI. Using findings at MRI, one malignant lesion that was assessed as benign at US was upgraded to potentially malignant. Conclusion O-RADS US and MRI had excellent performance and positive correlation, but significant interobserver variability remains. Keywords: Ovary, MR Imaging, Ultrasonography © RSNA, 2022 See also the commentary by Baumgarten in this issue.

Thyroid Nodule Shape Independently Predicts Risk of Malignancy.

CONTEXT: Predictive models of thyroid nodule cancer risk are presently based upon nodule composition, echogenicity, margins, and the presence of microcalcifications. Nodule shape has shown promise to be an additive factor helping determine the need for nodule biopsy. OBJECTIVE: We sought to determine if calculation of a nodule's spherical shape independently associates with cancer risk. METHODS: This prospective cohort study, conducted at a single large academic healthcare system in the United States, included patients with 1 or 2 clinically relevant thyroid nodules (predominantly solid and over 1 cm) presenting for diagnostic evaluation. Thyroid ultrasound, cytological evaluation with fine-needle biopsy, and/or histopathological examination on occasion of thyroid surgery were performed. We calculated the nodule's long to short ratio (spherical shape), and its association with tissue proven benign or malignant endpoints. RESULTS: The long to short nodule ratio was significantly lower in malignant compared to benign nodules indicating greater risk of malignancy in more spherical nodules (1.63 ±â€…0.38 for malignant nodules vs 1.74 ±â€…0.47 for benign, P < 0.0001). The risk of malignancy continually increased as the long to short ratio approached a purely spherical ratio of 1.0 (ratio > 2.00, 14.6% cancer; ratio 1.51-2.00, 19.7%; ratio 1.00-1.50, 25.5%, P < 0.0001). In multiple regression analysis, younger age, male sex, and nodule's spherical shape were each independently associated with cancer risk. CONCLUSION: The more a thyroid nodule is spherically shaped, as indicated by a long to short ratio approaching 1.0, the greater its risk of malignancy. This was independent of age, sex, and nodule size. Incorporating a nodule's sphericity in the risk stratification systems may improve individualized clinical decision making.