Anne Kennedy

Hydrops fetalis has many potential causes and a grave prognosis without treatment, and diagnosis requires a stepwise evaluation, starting with assessing fetal anemia to narrow the differential diagnosis and guide treatment options.

Use of an algorithmic approach to evaluate the posterior fossa and midline structures and assess for cortical developmental or destructive lesions allows radiologists to distinguish among the different causes of fetal hydrocephalus.

The Society of Radiologists in Ultrasound First-Trimester US Lexicon recommends well-defined, scientific, and specific terminology to communicate clearly across disciplines, minimize bias and harm, and respect patient preferences.

The rate of cesarean section (CS) for delivery has increased internationally, reaching 50% in some countries. Abnormal implantation of a new pregnancy at the site of the prior hysterotomy is an important complication because of the risks of hemorrhage, uterine rupture, and progression to placenta accreta spectrum (PAS), a condition with high morbidity with potential for catastrophic obstetric hemorrhage, maternal and fetal mortality, and loss of fertility. Cesarean scar ectopic pregnancy (CSEP) is the recommended term to describe these pregnancies, which are recognized on the basis of the sac implantation site, growth pattern, and associated abnormal perfusion. The true incidence of CSEP is unknown because the condition is likely underdiagnosed and underreported. The 2022 Society for Maternal-Fetal Medicine consult series notes that severe maternal morbidity and mortality are linked to difficulty in making the diagnosis of CSEP. The authors review the signs of CSEP at imaging, some pitfalls that may lead to delayed or missed diagnosis, and the consequences thereof. CSEPs must be differentiated from low implantation of a normal pregnancy, cervical ectopic pregnancy, and evolving pregnancy loss. Early recognition allows prompt and safe treatment that is usually surgical. Early treatment results in decreased health care costs, a shorter hospital stay, preservation of fertility, and prevention of iatrogenic preterm delivery, which is typical in cases that progress to PAS. Hysterectomy has serious negative psychologic consequences for patients of childbearing age; early diagnosis and prompt treatment of CSEP can prevent this often-ignored complication. ^©RSNA, 2024 Supplemental material is available for this article.

Fetal genitourinary anomalies can present a diagnostic challenge for the radiologist. The absence of a normally located kidney may represent agenesis or be secondary to a fusion or migration abnormality. A dilated renal pelvis should prompt evaluation for a specific cause, including ureteropelvic junction obstruction, reflux, or an obstructed duplicated system. Cystic parenchymal changes are characteristic of a multicystic dysplastic kidney but may also be seen in obstructive cystic dysplasia. There are numerous causes of megacystis including chromosomal (trisomy 18 syndrome), obstruction (posterior urethral valves, urethral atresia), or muscular dysfunction (prune belly syndrome, megacystis microcolon intestinal hypoperistalsis syndrome). Important mimics of a large bladder include hydrocolpos and urogenital sinus or cloacal malformation. Complications of genitourinary malformations are common and include oligohydramnios, urinary ascites, and urinoma. Making an accurate diagnosis often requires additional US views beyond those obtained in the standard fetal survey and occasionally performing fetal MRI. The appropriate use of orthogonal T2-weighted sequences, in conjunction with diffusion-weighted images for evaluation of the kidneys and gradient-recalled-echo sequences for evaluation of T1-hyperintense meconium in the colon, can play an integral role in diagnosis. Accurate diagnosis of fetal genitourinary malformations is vital to direct patient counseling and pregnancy management as outcomes are highly variable. Some conditions can be surgically corrected quite simply, some require multiple complex procedures, and some are lethal. The authors offer troubleshooting tips to narrow the differential diagnosis for four observations: unilateral absent kidney, dilated renal pelvis, cystic renal parenchyma, and megacystis and its mimics. ^©RSNA, 2023 Test Your Knowledge questions are available in the Online Learning Center.

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.

Methotrexate is administered for the management of disorders arising from trophoblastic tissue, specifically ectopic pregnancy and gestational trophoblastic disorders, and a knowledge of the expect... Methotrexate (MTX) is the primary pharmaceutical agent that is used for management of disorders arising from trophoblastic tissue. Its widespread international use is mostly attributable to its non...

Fetal growth abnormalities have significant neonatal and maternal consequences, and US identification and surveillance of abnormal fetal growth patterns, with careful attention to gestational datin... Fetal growth abnormalities have significant consequences for pregnancy management and maternal and fetal well-being. The accurate diagnosis of fetal growth abnormalities contributes to optimal ante...

In patients with pelvic pain, corpus luteum with associated ovarian edema (CLOE) may be mistaken for ovarian torsion on ultrasound or CECT.