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.

Simple Adnexal Cysts: SRU Consensus Conference Update on Follow-up and Reporting.

This multidisciplinary consensus update aligns prior Society of Radiologists in Ultrasound (SRU) guidelines on simple adnexal cysts with recent large studies showing exceptionally low risk of cancer associated with simple adnexal cysts. Most small simple cysts do not require follow-up. For larger simple cysts or less well-characterized cysts, follow-up or second opinion US help to ensure that solid elements are not missed and are also useful for assessing growth of benign tumors. In postmenopausal women, reporting of simple cysts greater than 1 cm should be done to document their presence in the medical record, but such findings are common and follow-up is recommended only for simple cysts greater than 3-5 cm, with the higher 5-cm threshold reserved for simple cysts with excellent imaging characterization and documentation. For simple cysts in premenopausal women, these thresholds are 3 cm for reporting and greater than 5-7 cm for follow-up imaging. If a cyst is at least 10%-15% smaller at any time, then further follow-up is unnecessary. Stable simple cysts at initial follow-up may benefit from a follow-up at 2 years due to measurement variability that could mask growth. Simple cysts that grow are likely cystadenomas. If a previously suspected simple cyst demonstrates papillary projections or solid areas at follow-up, then the cyst should be described by using standardized terminology. These updated SRU consensus recommendations apply to asymptomatic patients and to those whose symptoms are not clearly attributable to the cyst. These recommendations can reassure physicians and patients regarding the benign nature of simple adnexal cysts after a diagnostic-quality US examination that allows for confident diagnosis of a simple cyst. Patients will benefit from less costly follow-up, less anxiety related to these simple cysts, and less surgery for benign lesions.

Ultrasound grayscale image quality comparison between a 2D intracavitary transducer and a 3D intracavitary transducer used in 2D mode: A phantom study.

PURPOSE: It is unclear if a 3D transducer with the special design of mechanical swing or 2D array could provide acceptable 2D grayscale image quality for the general diagnosis purpose. The aim of this study is to compare the 2D image quality of a 3D intracavitary transducer with a conventional 2D intracavitary transducer using clinically relevant phantom experiments. METHODS: All measurements were performed on a GE Logiq E9 scanner with both a 2D (IC5-9-D) and a 3D (RIC5-9-D) transducer used in 2D mode. Selection of phantom targets and acquisition parameters were determined from analysis of 33 clinical pelvic exams. Depth of penetration (DOP), contrast response, contrast of anechoic cylinders (diameter: 6.7 mm) at 1.5 and 4.5 cm depths in transverse planes, and in-plane resolution represented by full-width half-maximum of pin targets at multiple depths were measured with transmit frequencies of 7 and 8 MHz. Spherical signal-noise-ratio (SNR) (diameter: 4 and 2 mm) at multiple depths were measured at 8 MHz. RESULTS: RIC5-9-D demonstrated <8% decrease in DOP for both transmit frequencies (7 MHz: 69.7 ± 8.2 mm; 8 MHz: 64.3 ± 7.8 mm) compared with those from IC5-9-D (7 MHz: 73.9 ± 4.4 mm; 8 MHz: 69.4 ± 7.8 mm). A decreased anechoic contrast was observed with a 4.5 cm depth for RIC5-9-D (7 MHz: 23.2 ± 1.8 dB, P > 0.05; 8 MHz: 17.7 ± 0.9 dB, P < 0.01) compared with IC5-9-D (7 MHz: 25.9 ± 1.2 dB; 8 MHz: 21.5 ± 0.8 dB). The contrast response and spatial resolution performance were comparable between the two transducers. RIC5-9-D showed comparable SNR of anechoic spheres compared to IC5-9-D. CONCLUSIONS: 2D images from a 3D probe exhibited comparable overall image quality for routine clinical pelvic imaging.

Double cervix: clarifying a diagnostic dilemma.

OBJECTIVE: Although double cervix is often considered to indicate uterus didelphys, it may be challenging to determine the true associated anomaly as double cervix occurs with other müllerian anomalies. Our purpose is to report the frequency of uterine müllerian anomalies that occur with a double cervix and identify imaging or clinical criteria to help classify the associated anomaly. STUDY DESIGN: After institutional review board approval, an electronic search was performed to identify patients with double cervix and pelvic magnetic resonance imaging (MRI) between 1976-2010 (using International Statistical Classification of Diseases and Related Health Problems, Edition 9 and Hospital International Classification of Diseases Adapted codes). MRIs were reviewed to classify the müllerian anomaly. Clinical characteristics including cervical canal thickness, intercervical distance and orientation were recorded. Kruskal-Wallis and χ(2) tests were used to test for differences in patient and imaging characteristics across müllerian anomalies. RESULTS: There were 64 patients who met inclusion criteria: 32 (50%) septate uterus, 27 (42%) uterus didelphys and 5 (8%) bicornuate uterus. Cervical canal divergence was present in 34% (11/32) with septate uterus, 26% (7/27) with uterus didelphys, and none with bicornuate uterus. Mean intercervical distance was significantly greater (P < .001) in uterus didelphys (12.05 mm) compared with septate (5.43 mm) or bicornuate uterus (5.40 mm). CONCLUSION: Septate uterus is as common as uterus didelphys, and considerably more common than bicornuate uterus, in women with a double cervix. Although a widened intercervical distance may support the MRI diagnosis of uterus didelphys, careful evaluation of the uterine fundus is required for correct diagnosis when encountering a double cervix.

Incidence of additional treatments in women treated with MR-guided focused US for symptomatic uterine fibroids: review of 138 patients with an average follow-up of 2.8 years.

PURPOSE: To assess long-term outcomes of magnetic resonance (MR)-guided focused ultrasound (US) treatments of uterine fibroids. MATERIALS AND METHODS: A retrospective follow-up of 138 patients treated at a single institution between March 2005 and November 2011 was conducted. The patients were not part of a clinical study and were followed through retrospective review of their medical records and telephone interviews to assess additional treatments for fibroid-related symptoms. Survival methods, including Cox proportional hazards models, were used to assess the association between incidence of additional treatments and patient data obtained during screening before treatment. RESULTS: The average length of follow-up was 2.8 years (range, 1-7.2 y). The cumulative incidence of additional treatments at 36 months and 48 months after MR-guided focused US was 19% and 23%, respectively. Women who did not need additional treatment were older than women who did (46.3 y ± 5.6 vs 43.0 y ± 5.8; P = .006; hazard ratio, 0.855; 95% confidence interval, 0.789-0.925). Additionally, women with heterogeneous or bright fibroids on T2-weighted MR imaging were more likely to require additional treatment compared with women with homogeneously dark fibroids (hazard ratio, 5.185 or 5.937, respectively; 95% confidence interval, 1.845-14.569 or 1.401-25.166, respectively). Physician predictions of treatment success, recorded during the screening process, had significant predictive value (P = .018). CONCLUSIONS: The long-term rates of additional interventions after MR-guided focused US of symptomatic uterine fibroids were found to be comparable with other uterine-sparing procedures, such as uterine artery embolization or myomectomy. Older patient age and homogeneously dark fibroids were associated with fewer additional treatments. Physician assessment of treatment success was found to be a valuable tool in patient screening.

Magnetic resonance-guided focused ultrasound of uterine leiomyomas: review of a 12-month outcome of 130 clinical patients.

PURPOSE: To assess 12-month outcomes and safety of clinical magnetic resonance (MR)-guided focused ultrasound (US) treatments of uterine leiomyomas. MATERIALS AND METHODS: Between March 2005 and December 2009, 150 women with symptomatic uterine leiomyomas were clinically treated with MR-guided focused US at a single institution; 130 patients completed treatment and agreed to have their data used for research purposes. Patients were followed through retrospective review of medical records and phone interviews conducted at 3-, 6-, and 12-month intervals after treatment to assess additional procedures and symptom relief. Outcome measures and treatment complications were analyzed for possible correlations with the appearance of the tumors on T2-weighted imaging. RESULTS: The cumulative incidence of additional tumor-related treatments 12 months after MR-guided focused US was 7.4% by the Kaplan-Meier method. At 3-, 6-, and 12-month follow-up, 86% (90 of 105), 93% (92 of 99), and 88% (78 of 89) of patients reported relief of symptoms, respectively. No statistically significant correlation between tumor appearance on T2-weighted imaging and 12-month outcome was found. Treatment-related complications were observed in 17 patients (13.1%): 16 patients had minor complications and one had a major complication (deep vein thrombosis). All complications were resolved within the 12-month follow-up period. CONCLUSIONS: MR-guided focused US is a noninvasive treatment option that can be used to effectively and safely treat uterine leiomyomas and delivers significant and lasting symptom relief for at least 12 months. The incidence of additional treatment during this time period is comparable with those in previous reports of uterine artery embolization.

Echogenic foci in the ovary: are they predictive of endometriosis?

OBJECTIVES: The purpose of this study was to determine whether sonographically depicted echogenic foci are more common in the ovaries of women with endometriosis when compared to the ovaries of women who do not have endometriosis. METHODS: Two radiologists blinded to the pathologic results reviewed the preoperative pelvic sonograms of consecutive women with a surgical diagnosis of endometriosis between June 2006 and October 2007. Results were compared with the preoperative sonograms of a control group of women without surgical evidence of endometriosis. The presence of echogenic foci in the ovaries and ovarian masses was recorded. RESULTS: Echogenic foci were present in the ovaries of 33 of 70 women (47%) with endometriosis and in the ovaries of 21 of 76 women (28%) without endometriosis (P = 0.015). When only patients with sonographically normal ovaries were evaluated by excluding endometriomas and other ovarian masses, echogenic foci were present in 8 of 23 women (35%) with endometriosis and in 10 of 42 women (24%) without endometriosis (P = .344). CONCLUSIONS: Echogenic foci are more commonly seen on sonography in the ovaries of women with endometriosis than in those without endometriosis, but this result seems largely due to ovarian endometriomas with echogenic foci in the walls. Echogenic foci are not predictive of endometriosis in women with otherwise sonographically normal ovaries.

Detection of distal ureteral stones in pregnancy using transvaginal ultrasound.

AIMS: To determine the performance of transvaginal ultrasound for the visualization of distal ureteral stones in pregnant patients with renal colic and to evaluate the diagnostic value of secondary findings suggestive of obstructing ureteral stone disease. METHODS: We retrospectively identified 129 pregnant patients with a total of 142 encounters with both abdominal and transvaginal ultrasound. Ultrasound images for each patient were reviewed recording the presence of stone with location, hydronephrosis, resistive indices (RI), and status of the ureteral jets. Patients were subcategorized into two groups based on the visualization of distal ureteral stone. RESULTS: The transvaginal technique identified 94% (N = 16/17) of sonographically detected stones in the distal ureter/urethra, while the transabdominal technique identified 29% (N = 5/17). The combined imaging for initial assessment of renal colic in pregnancy demonstrated a sensitivity of 89%, specificity 100%, and negative predictive value (NPV) of 98%. The frequency of hydronephrosis was statistically greater in the visualized stone group (94% vs 51%). Mean RI was identical in both groups however the delta RI was significantly elevated in those patients with distal ureteral stones with a mean delta RI value of 0.05. The rate of absence of ureteral jets was not statistically significant. CONCLUSION: The present data would suggest a utility of transvaginal ultrasound for the evaluation of the pregnant patient with 94% of distal stones being detected transvaginal versus 29% transabdominally. Additionally, there was significantly increased hydronephrosis and elevated RIs in patients with distal ureteral stones.

Adnexal masses: US characterization and reporting.

Pelvic ultrasonography (US) remains the imaging modality most frequently used to detect and characterize adnexal masses. Although evaluation is often aimed at distinguishing benign from malignant masses, the majority of adnexal masses are benign. About 90% of adnexal masses can be adequately characterized with US alone. In this article, the important US features that should allow one to make a reasonably confident diagnosis in most cases will be discussed. The role of follow-up US and alternative imaging modalities, along with the importance of careful reporting of adnexal masses, will also be reviewed.

Management of asymptomatic ovarian and other adnexal cysts imaged at US: Society of Radiologists in Ultrasound Consensus Conference Statement.

The Society of Radiologists in Ultrasound convened a panel of specialists from gynecology, radiology, and pathology to arrive at a consensus regarding the management of ovarian and other adnexal cysts imaged sonographically in asymptomatic women. The panel met in Chicago, Ill, on October 27-28, 2009, and drafted this consensus statement. The recommendations in this statement are based on analysis of current literature and common practice strategies, and are thought to represent a reasonable approach to asymptomatic ovarian and other adnexal cysts imaged at ultrasonography.

Sonographic diagnosis of conjoined diamniotic monochorionic twins.

According to traditional theories for the pathogenesis of conjoined twins, diamniotic placentation should not occur. We present an unusual case with diamniotic/monochorionic conjoined twins and discuss possible etiologic hypotheses. The diagnosis of this improbable case was made in the first trimester using ultrasound, which assisted in making an early decision regarding further management.

Initial evaluation of acoustic reflectors for the preservation of sensitive abdominal skin areas during MRgFUS treatment.

During MR-guided focused ultrasound (MRgFUS) treatments of uterine fibroids using ExAblate(R)2000 (InSightec, Haifa, Israel), individual tissue ablations are performed extracorporeally through the patient's abdomen using an annular array FUS transducer embedded within the MR table. Ultrasound intensities in the near field are below therapeutic levels and, under normal conditions, heating of the patient skin is minimal. However, increased absorption of ultrasound energy within sensitive skin areas or areas with differing acoustic properties, such as scars, may lead to skin burns and therefore these areas must be kept outside the near field of the FUS beam. Depending on their location and size the sensitive areas may either obstruct parts of the fibroid from being treated or prevent the entire MRgFUS treatment altogether. The purpose of this work is to evaluate acoustic reflector materials that can be applied to protect skin and the underlying sensitive areas. Reflection coefficients of cork (0.88) and foam (0.91) based materials were evaluated with a hydrophone. An ExAblate 2000 MRgFUS system was used to simulate clinical treatment with discs of reflector materials placed in a near field underneath a gel phantom. MR thermometry was used to monitor temperature elevations as well as the integrity of the focal spot. The phantom measurements showed acoustic shadow zones behind the reflectors with zone depths changing between 7 and 27 mm, for reflector disc diameters increasing from 10 to 30 mm (40 mm diameter discs completely blocked the FUS beam at the depth evaluated). The effects on thermal lesions due to the presence of the reflectors in the FUS beam were found to diminish with decreasing disc diameter and increasing sonication depth. For a 20 mm diameter disc and beyond 50 mm sonication depth, thermal lesions were minimally affected by the presence of the disc. No heating was observed on the skin side of the foam reflectors, as confirmed by measurements performed with adhesive temperature labels. We present these data and discuss possible applications to clinical MRgFUS treatments.

The utility of pelvic coil SNR testing in the quality assurance of a clinical MRgFUS system.

During MRI-guided focused ultrasound (MRgFUS) treatments of uterine fibroids using ExAblate 2000, tissue ablations are delivered by a FUS transducer while MR imaging is performed with a pelvic receiver coil. The consistency of the pelvic coil performance is crucial for reliable MR temperature measurements as well as detailed anatomic imaging in patients. Test sonications in a gel phantom combined with MR thermometry are used to test the performance of the FUS transducer prior to each treatment. As we show, however, these tests do not adequately evaluate receiver coil performance prior to clinical use. This could become a problem since the posterior part of the coil is frequently moved and can malfunction. The aim of this work is to demonstrate the utility of the signal-to-noise ratio (SNR) as a reliable indicator of pelvic coil performance. Slight modification of the vendor-provided coil support was accomplished to assure reproducible coil positioning. The SNR was measured in a gel phantom using axial acquisitions from the 3D-localizer scan. MR temperature and SNR measurements were obtained using a degraded receiver coil (with posterior element removed) and a known faulty coil, and compared to those obtained with a fully functioning coil. While the MR temperature-based tests were insensitive to change in pelvic coil performance, (degraded, p = 0.24; faulty, p = 0.28), the SNR tests were highly sensitive to coil performance, (degraded, p < 0.001; faulty, p < 0.001). Additional clinical data illustrate the utility of SNR testing of the receiver coil. These tests require minimal (or possibly no) additional scan time and have proven to be effective in our clinical practice.

Ovarian stromal hyperthecosis: sonographic features and histologic associations.

OBJECTIVE: Ovarian stromal hyperthecosis (SH) has variable clinical importance but can cause hyperandrogenism, particularly in premenopausal women. Sonography is often used to evaluate the ovaries of women with hyperandrogenism, but there is little published regarding the sonographic appearance of SH. The primary purpose of this study was to describe the sonographic features of SH. METHODS: A computerized search of our institution's pathology and imaging databases from 1996 through 2007 was performed to identify patients with histologically proven SH who had pelvic sonography before surgery. Sonograms and histologic findings were reviewed in each case. RESULTS: Twenty ovaries with SH were identified, occurring in 14 patients with a mean age of 59.8 years (range, 36-83 years). The SH was bilateral in 6 patients, unilateral in 6, and of uncertain laterality in 2 with a unilateral oophorectomy. Sonographic findings were as follows: 5 normal, 1 with a hemorrhagic cyst (later resolved) and otherwise normal, 3 enlarged but otherwise normal, 1 with a solid mass due to the nodular form of SH, 1 with a solid mass due to a fibroma, 2 with polycystic ovaries, and 7 not seen. Six of the 14 patients (43%) also had an ovarian fibrothecoma. CONCLUSIONS: Ovarian SH has variable sonographic features. Most commonly, the affected ovaries are either normal or slightly enlarged. A solid mass may infrequently be visible, and polycystic ovary syndrome changes may coexist with SH. A possible association of SH with fibrothecoma was also noted, which to our knowledge has not been previously reported.

Neonatal thyroid function after administration of IV iodinated contrast agent to 21 pregnant patients.

OBJECTIVE: The objective of our study was to document neonatal thyroid function after in utero exposure to nonionic iodinated contrast material to determine the potential risk of subsequent neonatal hypothyroidism. MATERIALS AND METHODS: We identified pregnant patients ("maternal patient") who underwent CT with iodinated IV contrast material between February 2000 and October 2006. The specifics of the CT examinations were reviewed including patient age, gestational age of conceptus at time of exposure, type of CT, and type and dose of contrast agent. The neonatal serum thyroid-stimulating hormone (TSH) level obtained from the exposed infant ("neonatal patient") was retrieved from the Minnesota Department of Health. RESULTS: Twenty-one patients gave us consent to review the requested data concerning their 23 children (two mothers had twins). Mean maternal age at the time of CT was 29 years (range, 19-41 years). Mean gestational age (based on last menstrual period) at the time of CT was 23 weeks (range, 8-37 weeks). Neonatal patients were born at a mean of 38 weeks of gestation (range, 24-41 weeks of gestation). Serum TSH was collected at a mean of 43 hours after delivery (range, 24-70 hours). For all neonatal patients, serum TSH levels were normal. Mean serum TSH was 9.7 muIU/mL (range, 2.2-28.8 muIU/mL). No maternal patient reported thyroid trouble in her child. CONCLUSION: Based on neonatal TSH measurements in a small number of patients, we found no ill effect of iodinated contrast agents on neonatal thyroid function after in utero exposure.

A clinical review of focused ultrasound ablation with magnetic resonance guidance: an option for treating uterine fibroids.

Uterine fibroids are common smooth muscle tumors, which can result in substantial symptoms affecting the quality of life of women. Whereas patients have several options available for treatment, focused ultrasound ablation is one of the least invasive treatment options outside medical therapy. Magnetic resonance-guided focused ultrasound (MRgFUS) ablation combines therapy delivered by an ultrasound transducer with imaging, guidance for therapy, and thermal feedback provided by magnetic resonance imaging. In 2004, the MRgFUS system ExAblate 2000 (InSightec, Haifa, Israel) was approved by the United States Food and Drug Administration for clinical treatments of uterine fibroids. Since its approval, our institution has performed more than 140 treatments. This paper provides an overview of our site's clinical experience with MRgFUS, including a brief description of the treatment system, pertinent features to review on screening magnetic resonance imaging, how the procedure is performed, and risks and benefits of the treatment. Some potential clinical applications of the technology are also briefly reviewed.

ACR Appropriateness Criteria® First Trimester Vaginal Bleeding.

Vaginal bleeding is not uncommon in the first trimester of pregnancy. The majority of such patients will have a normal intrauterine pregnancy (IUP), a nonviable IUP, or an ectopic pregnancy. Ultrasound (US) is the primary imaging modality in evaluation of these patients. US, along with clinical observations and serum human chorionic gonadotropin levels, can usually distinguish these causes. Although it is important to diagnose ectopic pregnancies and nonviable IUPs, one should also guard against injury to normal pregnancies due to inappropriate treatment with methotrexate or surgical intervention. Less common causes of first trimester vaginal bleeding include gestational trophoblastic disease and arteriovenous malformations. Pulsed methods of Doppler US should generally be avoided in the first trimester when there is a normal, or a potentially normal, IUP. Once a normal IUP has been excluded, Doppler US may be useful when other diagnoses such as retained products of conception or arteriovenous malformations are suspected. MRI may occasionally be helpful as a problem-solving tool. 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 include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Ovarian-Adnexal Reporting Lexicon for Ultrasound: A White Paper of the ACR Ovarian-Adnexal Reporting and Data System Committee.

Ultrasound is the most commonly used imaging technique for the evaluation of ovarian and other adnexal lesions. The interpretation of sonographic findings is variable because of inconsistency in descriptor terminology used among reporting clinicians. The use of vague terms that are inconsistently applied can lead to significant differences in interpretation and subsequent management strategies. A committee was formed under the direction of the ACR initially to create a standardized lexicon for ovarian lesions with the goal of improving the quality and communication of imaging reports between ultrasound examiners and referring clinicians. The ultimate objective will be to apply the lexicon to a risk stratification classification for consistent follow-up and management in clinical practice. This white paper describes the consensus process in the creation of a standardized lexicon for ovarian and adnexal lesions and the resultant lexicon.

Radiation exposure and pregnancy: when should we be concerned?

The potential biological effects of in utero radiation exposure of a developing fetus include prenatal death, intrauterine growth restriction, small head size, mental retardation, organ malformation, and childhood cancer. The risk of each effect depends on the gestational age at the time of exposure, fetal cellular repair mechanisms, and the absorbed radiation dose level. A comparison between the dose levels associated with each of these risks and the estimated fetal doses from typical radiologic examinations lends support to the conclusion that fetal risks are minimal and, therefore, that radiologic and nuclear medicine examinations that may provide significant diagnostic information should not be withheld from pregnant women. The latter position is advocated by the International Commission on Radiological Protection, National Council on Radiation Protection, American College of Radiology, and American College of Obstetrics and Gynecology. However, although the risks are small, it is important to ensure that radiation doses are kept as low as reasonably achievable.