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.

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.

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.

An Assessment of the Clinical Accuracy of Ultrasound in Diagnosing Cirrhosis in the Absence of Portal Hypertension.

Ultrasound is an invaluable tool for the diagnosis of hepatocellular carcinoma and portal hypertension. However, the accuracy of ultrasound in diagnosing cirrhosis in the absence of portal hypertension has not been well studied. Using the specific terms cirrhosis or nodular(ity), a retrospective evaluation was conducted on abdominal ultrasounds performed between 2008 and 2013. Patients with evidence of portal hypertension were excluded from the evaluation. Charts were reviewed for evidence of cirrhosis on liver biopsy performed within 1 year of the ultrasound. Of the 69 patients whose ultrasound findings reported cirrhosis without portal hypertension who underwent liver biopsy, 47 (68%) had histologic evidence of cirrhosis. When patients with advanced fibrosis (F3 or F4) on liver biopsy were included, the sensitivity of the ultrasound improved to 80%. One in 5 biopsies showed only mild to moderate or no fibrosis (F0-F2). Sonographic assessment by experts may falsely suggest or overestimate cirrhosis. In the absence of objective evidence of portal hypertension, caution should be taken in diagnosing cirrhosis based on sonographic interpretation alone.

Hepatic steatosis after pediatric liver transplant.

Hepatic steatosis develops after liver transplantation (LT) in 30% of adults, and nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in nontransplanted children. However, posttransplant steatosis has been minimally studied in pediatric LT recipients. We explored the prevalence, persistence, and association with chronic liver damage of hepatic steatosis in these children. In this single-center study of pediatric patients transplanted 1988-2015 (n = 318), 31% of those with any posttransplant biopsy (n = 271) had ≥ 1 biopsy with steatosis. Median time from transplant to first biopsy with steatosis was 0.8 months (interquartile range [IQR], 0.3-6.5 months) and to last biopsy with steatosis was 5.5 months (IQR, 1.0-24.5 months); 85% of patients with steatosis also had for-cause biopsies without steatosis. All available for-cause biopsies were re-evaluated (n = 104). Of 9 biopsies that could be interpreted as nonalcoholic steatohepatitis (NASH)/borderline NASH, with steatosis plus inflammation or ballooning, 8 also had features of cholestasis or rejection. Among 70 patients with surveillance biopsies 3.6-20.0 years after transplant, only 1 overweight adolescent had a biopsy with NAFLD (grade 1 steatosis, mild inflammation, no ballooning or fibrosis)-despite a 30% prevalence of overweight/obesity in the cohort and 27% with steatosis on previous for-cause biopsy. Steatosis on preceding for-cause biopsy was not associated with portal (P = 0.49) or perivenular fibrosis (P = 0.85) on surveillance biopsy. Hepatic steatosis commonly develops early after transplant in children and adolescents, but it rarely persists. Biopsies that did have steatosis with NASH characteristics were all for-cause, mostly in patients with NAFLD risk factors and/or confounding causes of liver damage. Prospective studies that follow children into adulthood will be needed to evaluate if and when hepatic steatosis presents a longterm risk for pediatric LT recipients. Liver Transplantation 23 957-967 2017 AASLD.

Sonography Predicts Liver Steatosis in Patients With Chronic Hepatitis B.

OBJECTIVES: Liver inflammation and fibrosis may impair the ability of sonography to identify steatosis. We determined the accuracy of sonography in grading steatosis in patients with chronic hepatitis B compared to liver biopsy. METHODS: We conducted was a single-center retrospective study of all nontransplanted patients with chronic hepatitis B undergoing sonography and liver biopsy between 2004 and 2014 (n = 109). Steatosis was graded by sonography as none, mild, moderate, or severe. Liver histologic analysis graded steatosis (0, <5%; 1, <33%; 2, <66%; or 3, ≥66%) and staged fibrosis (F0-F4). Severe steatosis was defined as grade 2 or 3. Clinical variables within 6 months of liver biopsy were collected, and the association with steatosis was analyzed by univariate logistic regression. RESULTS: Patients were predominantly Asian (83%), male (62%), and hepatitis B e antigen negative (62%). Twenty-nine percent of patients were obese; 9% had diabetes mellitus; 23% had hypertension; and 31% had dyslipidemia. Forty-four percent of patients had steatosis on liver biopsy; 8% had severe steatosis. The presence of any steatosis on sonography correctly identified any steatosis on liver biopsy in 29 of 48 patients (60%). The absence of steatosis on sonography ruled out severe steatosis on biopsy (specificity, 100%). Severe steatosis on sonography correctly predicted the presence of severe steatosis on liver biopsy (89%; P < .001); however, it was not accurate at distinguishing between steatosis grades. Predictors of biopsy-proven steatosis on univariate analysis included diabetes (P < .001), hypertension (P = .03), hypercholesterolemia (P = .02), and body mass index (P < .001). CONCLUSIONS: Sonography had excellent accuracy in identifying patients with steatosis on biopsy. Abdominal sonography can be used to predict clinically important steatosis in patients with chronic hepatitis B.

Radiologic assessment of fetal tracheal balloon occlusion.

Fetal endoscopic tracheal occlusion (FETO) is a novel technique to treat cases of isolated severe congenital diaphragmatic hernia (CDH). Although there are benefits of MRI over ultrasound in assessing lung volumes, it is unknown whether there are benefits of MRI for localizing the tracheal balloon. This is a retrospective study reviewing the imaging characteristics of FETO in patients who underwent both MRI and ultrasound exams done to localize tracheal balloons.

US Findings in Patients at Risk for Pancreas Transplant Failure.

Purpose To determine if ultrasonographic (US) findings, including Doppler US findings, are associated with subsequent pancreas transplant failure. Materials and Methods A cohort of adult patients who underwent pancreas transplantation at a tertiary institution over the course of 10 years (from 2003 to 2012) was retrospectively evaluated for failure, which was defined as return to insulin therapy or surgical graft removal. The institutional review board provided a waiver of informed consent. All US images obtained within the 1st postoperative year were reviewed for three findings: arterial flow (presence or absence of intraparenchymal forward diastole flow), splenic vein thrombus, and edema. These findings were correlated with pancreas graft failure within 1-year after surgery by using Cox proportional hazards models and hazard ratios. Results A total of 228 transplants were included (mean patient age, 41.6 years; range, 19-57 years; 122 men, 106 women). Absent or reversed arterial diastolic flow was identified in nine of 20 failed transplants (sensitivity, 45%; 95% confidence interval [CI]: 23, 68) and in 15 of 208 transplants that survived (specificity, 93% [193 of 208]; 95% CI: 89, 96). The Cox proportional hazard ratio was 6.2 (95% CI: 3.1, 12.4). Splenic vein thrombus was identified in 10 of 20 failed transplants (sensitivity, 50%; 95% CI: 27, 73) and in 25 of 208 transplants that survived (specificity, 88% [183 of 208]; 95% CI: 83, 92). The Cox proportional hazard ratio was 4.2 (95% CI: 2.4, 7.4). Edema had the lowest specificity (Cox proportional hazard ratio, 2.0; 95% CI: 1.3, 2.9). In the multivariate analysis, only absent or reversed arterial diastolic flow remained significantly associated with transplant failure (adjusted hazard ratio, 3.6; 95% CI: 1.0, 12.8; P = .045). Conclusion Absent or reversed diastolic arterial Doppler flow has a stronger association with transplant failure than does splenic vein thrombus or edema. (©) RSNA, 2016.

Outcomes of fetal intervention for primary hydrothorax.

OBJECTIVE: Primary hydrothorax is a rare congenital anomaly with outcomes ranging from spontaneous resolution to fetal demise. We reviewed our experience with fetuses diagnosed with primary hydrothorax to evaluate prenatal management strategies. METHODS: We reviewed the records of patients evaluated for fetal pleural effusions at our Fetal Treatment Center between 1996 and 2013. To define fetuses with primary hydrothorax, we excluded those with structural or genetic anomalies, diffuse lymphangiectasia, immune hydrops, and monochorionic diamniotic twin gestations. RESULTS: We identified 31 fetuses with primary hydrothorax, of whom 24 had hydrops. Hydropic fetuses were more likely to present with bilateral effusions. Of all fetuses with primary hydrothorax, 21 had fetal interventions. Survival without hydrops was 7/7 (100%), whereas survival with hydrops depended on whether or not the patient had fetal intervention: 12/19 (63%) with intervention and 1/5 (20%) without intervention. Premature delivery was common (44%) among those who had fetal intervention. CONCLUSIONS: Fetal intervention for primary hydrothorax may lead to resolution of hydrops, but preterm birth and neonatal demise still occur. Understanding the pathophysiology of hydrops may provide insights into further prenatal management strategies, including targeted therapies to prevent preterm labor.

Risk of thyroid cancer based on thyroid ultrasound imaging characteristics: results of a population-based study.

IMPORTANCE: There is wide variation in the management of thyroid nodules identified on ultrasound imaging. OBJECTIVE: To quantify the risk of thyroid cancer associated with thyroid nodules based on ultrasound imaging characteristics. METHODS: Retrospective case-control study of patients who underwent thyroid ultrasound imaging from January 1, 2000, through March 30, 2005. Thyroid cancers were identified through linkage with the California Cancer Registry. RESULTS: A total of 8806 patients underwent 11,618 thyroid ultrasound examinations during the study period, including 105 subsequently diagnosed as having thyroid cancer. Thyroid nodules were common in patients diagnosed as having cancer (96.9%) and patients not diagnosed as having thyroid cancer (56.4%). Three ultrasound nodule characteristics--microcalcifications (odds ratio [OR], 8.1; 95% CI, 3.8-17.3), size greater than 2 cm (OR, 3.6; 95% CI, 1.7-7.6), and an entirely solid composition (OR, 4.0; 95% CI, 1.7-9.2)--were the only findings associated with the risk of thyroid cancer. If 1 characteristic is used as an indication for biopsy, most cases of thyroid cancer would be detected (sensitivity, 0.88; 95% CI, 0.80-0.94), with a high false-positive rate (0.44; 95% CI, 0.43-0.45) and a low positive likelihood ratio (2.0; 95% CI, 1.8-2.2), and 56 biopsies will be performed per cancer diagnosed. If 2 characteristics were required for biopsy, the sensitivity and false-positive rates would be lower (sensitivity, 0.52; 95% CI, 0.42-0.62; false-positive rate, 0.07; 95% CI, 0.07-0.08), the positive likelihood ratio would be higher (7.1; 95% CI, 6.2-8.2), and only 16 biopsies will be performed per cancer diagnosed. Compared with performing biopsy of all thyroid nodules larger than 5 mm, adoption of this more stringent rule requiring 2 abnormal nodule characteristics to prompt biopsy would reduce unnecessary biopsies by 90% while maintaining a low risk of cancer (5 per 1000 patients for whom biopsy is deferred). CONCLUSIONS AND RELEVANCE: Thyroid ultrasound imaging could be used to identify patients who have a low risk of cancer for whom biopsy could be deferred. On the basis of these results, these findings should be validated in a large prospective cohort.

Tumor metrics and morphology predict poor prognosis in prenatally diagnosed sacrococcygeal teratoma: a 25-year experience at a single institution.

PURPOSE: Some fetuses with sacrococcygeal teratoma (SCT) develop hydrops, but there is no consensus on an appropriate prognostic marker for poor prognosis. The purpose of this study is to establish predictors of poor prognosis in fetuses with SCT. METHODS: A retrospective review of patients with prenatally diagnosed SCT from 1986 to 2011 was performed. Patients with outcome data and ultrasound exams before 32 weeks gestational age (GA) were included (n=37). Tumor volume-to-fetal weight ratio (TFR) and tumor morphology were assessed as sonographic predictors of poor prognosis. RESULTS: Twelve patients (32%) had good prognosis, and twenty-five patients (68%) had poor prognosis. All patients with poor prognosis had a morphology score ≥ 3, which is a significant predictor of poor prognosis (p <0.0001). TFR was assessed, and a receiver operating characteristic (ROC) analysis identified a cutoff value of 0.12 before 24 weeks GA and 0.11 before 32 weeks GA as predictors for poor prognosis. TFR is a significant predictor of poor prognosis (p<0.0001). CONCLUSIONS: Patients with cystic SCT all had good prognosis. TFR >0.12 was validated as a sonographic predictor of poor prognosis. TFR and tumor morphology can be used to counsel expectant families with prenatally diagnosed SCT regarding prognosis.

The diagnosis and management of intradiaphragmatic extralobar pulmonary sequestrations: a report of 4 cases.

BACKGROUND/PURPOSE: Intradiaphragmatic extralobar pulmonary sequestrations (IDEPSs) are a rare subset of bronchopulmonary sequestrations (BPS). We report the largest series of patients with IDEPS and describe the diagnostic and operative challenges associated with this condition. METHODS: We retrospectively reviewed our experience with fetal and pediatric BPS from 1995 to 2010 to identify patients with IDEPS. RESULTS: We identified 27 patients with BPS and 4 patients in whom the masses were within the diaphragm. In 1 patient, the prenatal ultrasound correctly identified the mass as being within the diaphragm itself, whereas the remaining cases were thought to be intraabdominal or had discordant preoperative imaging findings. The diagnosis of an IDEPS proved challenging to make prospectively using prenatal ultrasound, computed tomography, or magnetic resonance imaging. All patients underwent attempted resection. Two cases required a combined laparoscopic and thoracoscopic approach to accurately localize the mass. The postoperative recovery of these patients was uneventful. CONCLUSIONS: We present the largest reported experience of IDEPS. Because preoperative imaging studies cannot always determine whether a sequestration is intraabdominal, intrathoracic, or intradiaphragmatic, operative planning may pose a challenge. However, the use of minimally invasive approaches can allow exploration of both the thoracic and abdominal cavities with low morbidity.

Microcystic congenital pulmonary airway malformation with hydrops fetalis: steroids vs open fetal resection.

BACKGROUND/PURPOSE: Congenital pulmonary airway malformations (CPAM) are rare lesions often diagnosed during routine prenatal ultrasound. The presence of hydrops fetalis is an indicator of poor prognosis. Here we present a retrospective review of fetuses undergoing either open fetal surgery or steroids for predominantly microcystic CPAM with hydrops fetalis. METHOD: A retrospective review of patients undergoing open fetal surgery or steroids for CPAM at our institution was performed. The primary outcome was survival. RESULTS: A retrospective review of all patients referred to our institution with the diagnosis of CPAM was performed. Fetuses with predominantly microcystic CPAM and the presence of hydrops fetalis treated with steroid or surgery were included. Thirteen patients were treated with steroids, and 11 patients underwent open fetal surgery. In the steroid group 12 (92%) of 13 fetuses survived to delivery versus 9 (82%) of 11 in the open fetal surgery group. Only 5 (56%) of 9 of the patients in the open fetal surgery group survived to neonatal discharge compared to 10 (83%) of 12 in the steroid group. CONCLUSIONS: In the present retrospective study, improved survival was seen in fetuses with hydrops fetalis and predominantly microcystic CPAM treated with steroids when compared with open fetal surgery. Steroids should be considered for first-line therapy in these cases.

Prenatal steroids for microcystic congenital cystic adenomatoid malformations.

OBJECTIVE: The purpose of this study is to evaluate the effect of prenatal steroid treatment in fetuses with sonographically diagnosed congenital cystic adenomatoid malformations (CCAMs). METHODS: This was an institutional review board-approved retrospective review of 372 patients referred to the University of California, San Francisco (UCSF), for fetal CCAM. Inclusion criteria were (1) a predominately microcystic CCAM lesion sonographically diagnosed at our institution, (2) maternal administration of a single course of prenatal corticosteroids (betamethasone), and (3) no fetal surgery. CCAM volume-to-head ratio (CVR), presence of hydrops, mediastinal shift, and diaphragm eversion were assessed before and after administration of betamethasone. The primary end points were survival to birth and neonatal discharge. RESULTS: Sixteen patients with predominantly microcystic CCAMs were treated with prenatal steroids. Three were excluded because of lack of follow-up information. All remaining fetuses (13/13) survived to delivery and 11/13 (84.6%) survived to neonatal discharge. At the time of steroid administration, all patients had CVR greater than 1.6, and 9 (69.2%) also had nonimmune hydrops fetalis. After a course of steroids, CVR decreased in 8 (61.5%) of the 13 patients, and hydrops resolved in 7 (77.8%) of the 9 patients with hydrops. The 2 patients whose hydrops did not resolve with steroid treatment did not survive to discharge. CONCLUSION: In high-risk fetal patients with predominantly microcystic CCAM lesions, betamethasone is an effective treatment. This series is a pilot study for a prospective randomized trial comparing treatment of CCAM with betamethasone to placebo.

The use of ultrasound in fetal surgery.

Obstetric ultrasound (US) is an integral part of fetal surgery for open and minimally invasive techniques. With advances in US imaging, the ability to refine diagnosis, predict prognosis, and contribute to fetal treatment continues to grow. Current research in fetal diagnosis and treatment includes identifying the most reliable sonographic features for determining prognosis before and after surgery.

Computerized prenatal genetic testing decision-assisting tool: a randomized controlled trial.

OBJECTIVE: Guidelines for fetal aneuploidy testing recommend that screening and diagnostic testing be made available to pregnant women of all ages and that providers explain the differences between these tests to help their patients make informed testing decisions. We sought to estimate the effect of a computerized, interactive prenatal testing decision tool on prenatal testing decision making. METHODS: Four hundred ninety-six English- or Spanish-speaking women at 20 or fewer weeks of gestation were randomly assigned to view the interactive prenatal testing decision tool or the California Department of Health Services' educational booklet. Primary outcomes were knowledge, risk awareness, intervention satisfaction, decisional conflict, and among women aged at least 35 years, use of invasive diagnostic testing. RESULTS: Women assigned to the interactive prenatal testing decision tool had higher knowledge scores (79.5% compared with 64.9%, P<.001), were more likely to correctly estimate their risk of procedure-related miscarriage (64.9% compared with 48.1%, P=.002) and carrying a Down syndrome-affected fetus (63.5% compared with 15.1%, P<.001), were more satisfied with the intervention (P<.001), and had less decision uncertainty (P<.001) than controls after viewing the intervention. Most of these differences persisted over time. Among women aged at least 35 years, the interactive prenatal testing decision tool viewers who were originally less inclined to undergo invasive testing were ultimately more likely than similarly inclined controls to have amniocentesis or chorionic villus sampling (44.8% compared with 29.2%), whereas those who were originally more inclined to undergo an invasive procedure ultimately were less likely than similarly inclined controls to have a diagnostic procedure (84.6% compared with 94.9%; P=.015 for interaction). CONCLUSION: Using an interactive prenatal testing decision tool results in more informed prenatal genetic testing decisions than viewing standard educational booklets. CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov, www.clinicaltrials.gov, NCT00686062 LEVEL OF EVIDENCE: I.

Colonic atresia and choledochal cyst: a rare combination.

Colonic atresia and choledochal cyst are rare congenital abnormalities and there are few cases of their coexistence reported in the literature. We report a case of choledochal cyst and colonic atresia in a term neonate. Our prenatal ultrasonographic and intraoperative findings support the idea that these two entities may be related.

Hook needle-guided excision of recurrent differentiated thyroid cancer in previously operated neck compartments: a safe technique for small, nonpalpable recurrent disease.

CONTEXT: As a result of more sensitive techniques to detect recurrent thyroid cancer, the number of patients presenting with small, nonpalpable recurrent thyroid cancer in cervical lymph nodes is increasing. Surgical excision of nonpalpable recurrent thyroid cancer can be difficult, particularly in a previously operated area. OBJECTIVE: The objective of this study was to investigate whether preoperative insertion of a hook needle under ultrasound guidance is useful in neck reoperations for recurrent thyroid cancer. PATIENTS: Ten consecutive patients presenting over a 4-month period with nonpalpable, ultrasound-visible, fine needle biopsy-proven recurrent thyroid cancer in previously operated neck compartment(s) were studied. MAIN OUTCOME MEASURES: We measured whether it was technically possible to insert a hook needle preoperatively, rate of negative neck exploration, and complication rate. RESULTS: The hook needle was inserted in seven patients. In three patients, the hook needle was not inserted; one patient had palpable disease 4 months after the preoperative clinic visit, one patient had a tumor too close to the carotid artery, and one patient had multiple bilateral foci of recurrent disease in the central neck. One patient had bleeding after insertion of the needle due to a penetration of an anterior jugular vein that was easily managed at neck reexploration. No other complication occurred during the hook needle insertion, and the only surgical complication was a transient recurrent nerve palsy. All pathology reports showed malignant disease. CONCLUSION: Hook needle-guided excision of recurrent thyroid cancer is feasible and appears to be a promising tool for safe and successful reoperation of patients with small recurrent thyroid cancer in cervical lymph nodes.

The likelihood ratio of sonographic findings for the diagnosis of hemorrhagic ovarian cysts.

OBJECTIVE: The purpose of this study was to quantify the likelihood ratio (LR) of specific sonographic features and experienced sonologist assessment in diagnosing a hemorrhagic ovarian cyst and to better understand the diagnostic power of sonography in making this diagnosis. METHODS: Two sonologists, blinded to the patient's clinical history, independently reviewed the sonograms of 252 adnexal masses. For each mass, each sonologist recorded features using a standardized checklist, which included observations regarding the presence of fibrin strands, a retracting clot, septations, and wall irregularity. Each reviewer independently chose 1 specific conclusion from a list of possibilities that included the diagnosis of a hemorrhagic ovarian cyst. Sonographic observations and sonologist predictions were compared with pathologic findings (n = 214) or follow-up sonography (n = 38). RESULTS: Of the 252 masses, there were 30 hemorrhagic cysts. One sonologist correctly identified 25 hemorrhagic cysts, with 1 false-positive, 2 false-negative, and 3 indeterminate calls (LR 185). The other sonologist correctly identified 24 hemorrhagic cysts, with 1 false-positive, 0 false-negative, and 6 indeterminate calls (LR 178). The 2 cases incorrectly diagnosed as hemorrhagic cysts were endometriomas at pathologic diagnosis. Specific sonographic observations and combinations of observations performed as follows: retracting clot (LR >67); fibrin strands (LR 40); fibrin strands and no septations (LR 100); and fibrin strands, no septations, and smooth wall (LR 200). CONCLUSIONS: Fibrin strands and a retracting clot are paramount observations in allowing high confidence in the diagnosis of hemorrhagic ovarian cysts. Approximately 90% of hemorrhagic ovarian cysts will exhibit at least 1 of these 2 features.