Biliary Duct Dilatation: AJR Expert Panel Narrative Review.

Biliary duct dilatation is a common incidental finding in practice, but it is unlikely to indicate biliary obstruction in the absence of clinical symptoms or elevated levels on liver function tests (LFTs). However, the clinical presentation may be nonspecific, and LFTs may either be unavailable or difficult to interpret. The goal of this AJR Expert Panel Narrative Review is to highlight a series of topics fundamental to the management of biliary duct dilatation, providing consensus recommendations in a question-and-answer format. We start by covering a basic approach to interpreting LFT results, the strengths and weaknesses of the biliary imaging modalities, and how and where to measure the extrahepatic bile duct. Next, we define the criteria for biliary duct dilatation, including patients with prior cholecystectomy and advanced age, and discuss when and whether biliary duct dilatation can be attributed to papillary stenosis or sphincter of Oddi dysfunction. Subsequently, we discuss two conditions in which the duct is pathologically dilated but not obstructed: congenital cystic dilatation (i.e., choledochal cyst) and intraductal papillary neoplasm of the bile duct. Finally, we provide guidance regarding when to recommend obtaining additional imaging or testing, such as endoscopic ultrasound or ERCP, and include a discussion of future directions in biliary imaging.

Conventional and Contrast-enhanced US of the Lung: From Performance to Diagnosis.

In recent years, lung US has evolved from a marginal tool to an integral component of diagnostic chest imaging. Contrast-enhanced US (CEUS) can improve routine gray-scale imaging of the lung and chest, particularly in diagnosis of peripheral lung diseases (PLDs). Although an underused tool in many centers, and despite inherent limitations in evaluation of central lung disease caused by high acoustic impedance between air and soft tissues, lung CEUS has emerged as a valuable tool in diagnosis of PLDs. Owing to the dual arterial supply to the lungs via pulmonary and bronchial (systemic) arteries, different enhancement patterns can be observed at lung CEUS, thereby enabling accurate differential diagnoses in various PLDs. Lung CEUS also assists in identifying patients who may benefit from complementary diagnostic tests, including image-guided percutaneous biopsy. Moreover, lung CEUS-guided percutaneous biopsy has shown feasibility in accessible subpleural lesions, enabling higher histopathologic performance without significantly increasing either imaging time or expenses compared with conventional US. The authors discuss the technique of and basic normal and pathologic findings at conventional lung US, followed by a more detailed discussion of lung CEUS applications, emphasizing specific aspects of pulmonary physiology, basic concepts in lung US enhancement, and the most commonly encountered enhancement patterns of different PLDs. Finally, they discuss the benefits of lung CEUS in planning and guidance of US-guided lung biopsy. ©RSNA, 2024 Supplemental material is available for this article.

Multimodality Imaging of Postmastectomy Breast Reconstruction Techniques, Complications, and Tumor Recurrence.

For women undergoing mastectomy, breast reconstruction can be performed by using implants or autologous tissue flaps. Mastectomy options include skin- and nipple-sparing techniques. Implant-based reconstruction can be performed with saline or silicone implants. Various autologous pedicled or free tissue flap reconstruction methods based on different tissue donor sites are available. The aesthetic outcomes of implant- and flap-based reconstructions can be improved with oncoplastic surgery, including autologous fat graft placement and nipple-areolar complex reconstruction. The authors provide an update on recent advances in implant reconstruction techniques and contemporary expanded options for autologous tissue flap reconstruction as it relates to imaging modalities. As breast cancer screening is not routinely performed in this clinical setting, tumor recurrence after mastectomy and reconstruction is often detected by palpation at physical examination. Most local recurrences occur within the skin and subcutaneous tissue. Diagnostic breast imaging continues to have a critical role in confirmation of disease recurrence. Knowledge of the spectrum of benign and abnormal imaging appearances in the reconstructed breast is important for postoperative evaluation of patients, including recognition of early and late postsurgical complications and breast cancer recurrence. The authors provide an overview of multimodality imaging of the postmastectomy reconstructed breast, as well as an update on screening guidelines and recommendations for this unique patient population. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Grading Abdominal Trauma: Changes in and Implications of the Revised 2018 AAST-OIS for the Spleen, Liver, and Kidney.

According to the Centers for Disease Control and Prevention, trauma is the leading cause of fatal injuries for Americans aged 1-44 years old and the fourth leading overall cause of death. Accurate and early diagnosis, including grading of solid organ injuries after blunt abdominal trauma (BAT), is crucial to guide management and improve outcomes. The American Association for the Surgery of Trauma (AAST) Organ Injury Scale (OIS) is the most widely accepted BAT scoring system at CT both within the United States and internationally, and its uses include stratification of injury severity, thereby guiding management, and facilitation of clinical research, billing, and coding. Furthermore, this system also plays a role in the credentialing process for trauma centers in the United States. The newly revised 2018 OIS provides criteria for grading solid organ damage into three groups: imaging, operation, and pathology. The final grade is based on the highest of the three criteria. If multiple lower-grade (I or II) injuries are present in a single organ, one grade is advanced to grade III. The most substantial change in the revised 2018 AAST-OIS is incorporation of multidetector CT findings of vascular injury, including pseudoaneurysm and arteriovenous fistula. The authors outline the main revised aspects of grading organ injury using the AAST-OIS for the spleen, liver, and kidney after BAT, particularly the role of multidetector CT and alternative imaging in organ injury detection, the importance of vascular injuries in grade change, and the impact of these changes on patient management and in prediction of operative treatment success and in-hospital mortality. ©RSNA, 2023 Supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article. Quiz questions for this article are available through the Online Learning Center.

Paraneoplastic Syndromes from Head to Toe: Pathophysiology, Imaging Features, and Workup.

Patients often have symptoms due to the mass effect of a neoplasm on surrounding tissues or the development of distant metastases. However, some patients may present with clinical symptoms that are not attributable to direct tumor invasion. In particular, certain tumors may release substances such as hormones or cytokines or trigger an immune cross-reactivity between malignant and normal body cells, resulting in characteristic clinical features that are broadly referred to as paraneoplastic syndromes (PNSs). Recent advances in medicine have improved the understanding of the pathogenesis of PNSs and enhanced their diagnosis and treatment. It is estimated that 8% of patients with cancer develop a PNS. Diverse organ systems may be involved, most notably the neurologic, musculoskeletal, endocrinologic, dermatologic, gastrointestinal, and cardiovascular systems. Knowledge of various PNSs is necessary, as these syndromes may precede tumor development, complicate the patient's clinical presentation, indicate tumor prognosis, or be mistaken for metastatic spread. Radiologists should be familiar with the clinical presentations of common PNSs and the selection of appropriate imaging examinations. Many of these PNSs have imaging features that can assist with arriving at the correct diagnosis. Therefore, the key radiographic findings associated with these PNSs and the diagnostic pitfalls that can be encountered during imaging are important, as their detection can facilitate early identification of the underlying tumor, reveal early recurrence, and enable monitoring of the patient's response to therapy. © RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Diversity in Radiology: Current Status and Trends Over the Past Decade.

Background There have been growing efforts nationally and institutionally toward diversity in radiology. Purpose To analyze sex and racial and ethnic diversity over time (2010-2019) for the various levels of the U.S. academic radiology physician workforce in context of the available pipeline of medical students and trainees. Materials and Methods Data on sex and race and ethnicity were collected among medical school applicants, graduates, radiology residency applicants, residents, and different levels of academic radiology faculty. All trainee data were obtained from two time points, 2010-2011 and 2019-2020. Radiology faculty data were collected from 2010 to 2019. The sex and racial and ethnic composition at each academic level was compared between 2010 and 2019 using the χ2 test and a significance level of P < .05. Results In 2019, the percentage of female faculty among radiology instructors was 38% (251 of 655); assistant professors, 31% (1503 of 4801); associate professors, 28% (600 of 2161); professors, 22% (424 of 1901); and department chairs, 17% (37 of 220). The proportion of female faculty increased from 2010 to 2019, with the greatest relative increase in percentages among the more senior faculty positions. However, the proportion of female department chairs has only increased from 13% (27 of 203) in 2010 to 17% (37 of 220) in 2019. Across training levels, the most abrupt change in composition of female trainees occurred from medical school matriculates (52%, 11 160 of 21 614) to radiology residency applicants (29%, 656 of 2274), which largely stayed unchanged from 2010 to 2019. The proportion of Black or African American department chairs was 5% (10 of 220) in 2019, which was higher compared with that of assistant professor, associate professor, and professor levels for Black or African American faculty (3% [130 of 4949], 2% [41 of 2208], and 2% [35 of 1924], respectively), with proportions of Hispanic faculty at 5% (240 of 4949), 4% (96 of 2208), and 3% (60 of 1924), respectively. These proportions have not changed since 2010. Conclusion Identifying and addressing reasons for the low proportion of female radiology residency applicants despite a highly diverse pool of medical students would be key to increasing female representation in the field. The low representation of African American and Hispanic individuals in academic radiology is seen at all levels and has not changed much over time. Efforts to increase diversity may need to be focused toward the medical school and residency application levels. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Pandharipande and Shah in this issue.

MR Imaging Biomarkers for the Prediction of Outcome after Radiofrequency Ablation of Hepatocellular Carcinoma: Qualitative and Quantitative Assessments of the Liver Imaging Reporting and Data System and Radiomic Features.

PURPOSE: To assess the Liver Imaging Reporting and Data System (LI-RADS) and radiomic features in pretreatment magnetic resonance (MR) imaging for predicting progression-free survival (PFS) in patients with nodular hepatocellular carcinoma (HCC) treated with radiofrequency (RF) ablation. MATERIAL AND METHODS: Sixty-five therapy-naïve patients with 85 nodular HCC tumors <5 cm in size were included in this Health Insurance Portability and Accountability Act-compliant, institutional review board-approved, retrospective study. All patients underwent RF ablation as first-line treatment and demonstrated complete response on the first follow-up imaging. Gadolinium-enhanced MR imaging biomarkers were analyzed for LI-RADS features by 2 board-certified radiologists or by analysis of nodular and perinodular radiomic features from 3-dimensional segmentations. A radiomic signature was calculated with the most informative features of a least absolute shrinkage and selection operator Cox regression model using leave-one-out cross-validation. The association between both LI-RADS features and radiomic signatures with PFS was assessed via the Kaplan-Meier analysis and a weighted log-rank test. RESULTS: The median PFS was 19 months (95% confidence interval, 16.1-19.4) for a follow-up period of 24 months. Multifocality (P = .033); the appearance of capsular continuity, compared with an absent or discontinuous capsule (P = .012); and a higher radiomic signature based on nodular and perinodular features (P = .030) were associated with poorer PFS in early-stage HCC. The observation size, presence of arterial hyperenhancement, nonperipheral washout, and appearance of an enhancing "capsule" were not associated with PFS (P > .05). CONCLUSIONS: Although multifocal HCC clearly indicates a more aggressive phenotype even in early-stage disease, the continuity of an enhancing capsule and a higher radiomic signature may add value as MR imaging biomarkers for poor PFS in HCC treated with RF ablation.

Pathologic Conditions at Imaging of the Spermatic Cord.

A wide range of benign and malignant processes can affect the spermatic cord (SC). Familiarity with and recognition of the characteristic imaging features of these entities are imperative for accurate diagnosis and optimal clinical care. While some SC diseases are self-limiting, others can result in infertility and potentially life-threatening infection or bleeding if they are left untreated. Therefore, correct diagnosis is important for life-saving treatment and preservation of fertility. Disorders including anomalies of the vas deferens and the processus vaginalis, arterial and venous diseases (torsion of the SC and varicoceles), infection, trauma, and neoplasms are the most pertinent entities with which radiologists should be familiar when assessing the SC. Knowing what to expect in a patient who has undergone SC interventions is imperative. US has a fundamental role in the initial examination of patients who present with symptoms that indicate abnormalities of the SC, such as suspected posttraumatic testicular retraction or SC torsion. Other imaging techniques including abdominal and pelvic MRI and CT have their own importance. For correct interpretation of the findings and to establish an accurate diagnosis, it is crucial to have a thorough knowledge of the anatomy, the utility and limitations of various imaging modalities, optimal imaging and scanning techniques, and the imaging features of various benign and malignant pathologic conditions that can involve the SC. Online supplemental material is available for this article. ©RSNA, 2022.

Manifestations of Sickle Cell Disorder at Abdominal and Pelvic Imaging.

Sickle cell disorder (SCD) refers to a spectrum of hematologic disorders that cause a characteristic clinical syndrome affecting the entire body. It is the most prevalent monogenetic hemoglobinopathy worldwide, with a wide range of focal and systemic expressions. Hemoglobin gene mutation leads to the formation of abnormal sickle-shaped red blood cells, which cause vascular occlusion and result in tissue and organ ischemia and infarction. Recurrent episodes of acute illness lead to progressive multisystem organ damage and dysfunction. Vaso-occlusion, hemolysis, and infection as a result of functional asplenia are at the core of the disease manifestations. Imaging plays an essential role in the diagnosis and management of SCD-related complications in the abdomen and pelvis. A thorough understanding of the key imaging findings of SCD complications involving hepatobiliary, gastrointestinal, genitourinary, and musculoskeletal systems is crucial to timely recognition and accurate diagnosis. The authors aim to familiarize the radiologist with the SCD spectrum, focusing on the detection and evaluation of manifestations that may appear at imaging of the abdomen and pelvis. The topics the authors address include (a) the pathophysiology of the disease, (b) the placement of SCD among hemoglobinopathies, (c) the clinical presentation of SCD, (d) the role of imaging in the evaluation and diagnosis of patients with SCD who present with abdominal and pelvic manifestations in addition to extraperitoneal manifestations detectable at abdominal or pelvic imaging, (e) imaging features associated with common and uncommon sequelae of SCD in abdominal and pelvic imaging studies, and (f) a brief overview of management and treatment of patients with SCD. Online supplemental material is available for this article. ©RSNA, 2022.

Imaging Review of Obstetric Sequelae of Maternal Diabetes Mellitus.

Diabetes mellitus, whether preexisting or gestational, poses significant risk to both the mother and the developing fetus. A myriad of potential fetal complications in the setting of diabetic pregnancies include, among others, congenital anomalies, delayed fetal lung maturity, macrosomia, and increased perinatal morbidity and mortality. Congenital anomalies most commonly involve the nervous, cardiovascular, genitourinary, and musculoskeletal systems. Delayed fetal lung maturity, probably secondary to hyperglycemia suppressing surfactant secretion, is a major determinant of perinatal morbidity and mortality. Besides the potential complications encountered during cesarean delivery in macrosomic fetuses, vaginal delivery is also associated with increased risks of shoulder dystocia, clavicular and humeral fractures, and brachial plexus palsy. Maternal complications are related to the increased risk of hypertensive diseases of pregnancy and associated preeclampsia and hemolysis, elevated liver function, and low platelets (HELLP) syndrome, as well as complications encountered at the time of delivery secondary to fetal macrosomia and cesarean delivery. Additional conditions encountered in the setting of maternal diabetes include polyhydramnios, placental thickening, and two-vessel umbilical cord, each of which is associated with adverse fetal and maternal outcomes including fetal growth restriction, preterm labor, placental abruption, and premature rupture of membranes. Imaging plays a vital role in the evaluation of the mother and the fetus and can provide invaluable information that can be used by maternal fetal medicine to manage this patient population effectively. The authors review the pathophysiologic alterations induced by diabetes in pregnancy, discuss the imaging spectrum of diabetic embryopathy, and provide a detailed review of potential associated maternal complications. Online supplemental material is available for this article. ©RSNA, 2021.

Vascular Anomaly Syndromes in the ISSVA Classification System: Imaging Findings and Role of Interventional Radiology in Management.

Vascular anomalies encompass a spectrum of tumors and malformations that can cause significant morbidity and mortality in children and adults. Use of the International Society for the Study of Vascular Anomalies (ISSVA) classification system is strongly recommended for consistency. Vascular anomalies can occur in isolation or in association with clinical syndromes that involve complex multifocal lesions affecting different organ systems. Thus, it is critical to be familiar with the differences and similarities among vascular anomalies to guide selection of the appropriate imaging studies and possible interventions. Syndromes associated with simple vascular malformations include hereditary hemorrhagic telangiectasia, blue rubber bleb nevus syndrome, Gorham-Stout disease, and primary lymphedema. Syndromes categorized as vascular malformations associated with other anomalies include Klippel-Trenaunay-Weber syndrome, Parkes Weber syndrome, Servelle-Martorell syndrome, Maffucci syndrome, macrocephaly-capillary malformation, CLOVES (congenital lipomatous overgrowth, vascular malformations, epidermal nevi, and scoliosis, skeletal, and spinal anomalies) syndrome, Proteus syndrome, Bannayan-Riley-Ruvalcaba syndrome, and CLAPO (capillary malformations of the lower lip, lymphatic malformations of the face and neck, asymmetry of the face and limbs, and partial or generalized overgrowth) syndrome. With PHACES (posterior fossa malformations, hemangiomas, arterial anomalies, cardiac defects and/or coarctation of the aorta, eye abnormalities, and sternal clefting or supraumbilical raphe) syndrome, infantile hemangiomas associated with other lesions occur. Diagnostic and interventional radiologists have important roles in diagnosing these conditions and administering image-guided therapies-embolization and sclerotherapy, and different ablation procedures in particular. The key imaging features of vascular anomaly syndromes based on the 2018 ISSVA classification system and the role of interventional radiology in the management of these syndromes are reviewed. Online supplemental material is available for this article. ©RSNA, 2022.

Imaging Cancer in Pregnancy.

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

Nonaccidental Injury in the Elderly: What Radiologists Need to Know.

Elder abuse may result in serious physical injuries and long-term psychological consequences and can be life threatening. Over the past decade, attention to elder abuse has increased owing to its high prevalence, with one in six people aged 60 years and older experiencing some form of abuse worldwide. Despite this, the detection and reporting rates remain relatively low. While diagnostic imaging is considered critical in detection of child abuse, it is relatively underused in elder abuse. The authors discuss barriers to use of imaging for investigation and diagnosis of elder abuse, including lack of training, comorbidities present in this vulnerable population, and lack of communication among the intra- and interdisciplinary care providers. Moreover, imaging features that should raise clinical concern for elder abuse are reviewed, including certain types of fractures (eg, posterior rib), characteristic soft-tissue and organ injuries (eg, shoulder dislocation), and cases in which the reported mechanism of injury is inconsistent with the imaging findings. As most findings suggesting elder abuse are initially discovered at radiography and CT, the authors focus mainly on use of those modalities. This review also compares and contrasts elder abuse with child abuse. Empowered with knowledge of elderly victims' risk factors, classic perpetrator characteristics, and correlative imaging findings, radiologists should be able to identify potential abuse in elderly patients presenting for medical attention. Future recommendations for research studies and clinical workflow to increase radiologists' awareness of and participation in elder abuse detection are also presented. An invited commentary by Jubanyik and Gettel is available online. Online supplemental material is available for this article. ©RSNA, 2022.

Sequelae of Eating Disorders at Imaging.

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

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.

Use of Methotrexate in Gynecologic and Obstetric Practice: What the Radiologist Needs to Know.

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 noninvasive, safe, and effective characteristics as a treatment option for ectopic pregnancy (EP) and gestational trophoblastic disease (GTD), with the large added benefit of fertility preservation. Although the effects of MTX usage are well documented in the gynecologic and obstetric literature, there is a scarcity of radiologic literature on the subject. Depending on the type of EP, the route of MTX administration and dosage may vary. US plays an essential role in the diagnosis and differentiation of various types of EPs, pregnancy-related complications, and complications related to MTX therapy, as well as the assessment of eligibility criteria for MTX usage. A knowledge of expected imaging findings following MTX treatment, including variability in echogenicity and shape of the EP, size fluctuations, changes in vascularity and gestational sac content, and the extent of hemoperitoneum, is essential for appropriate patient management and avoidance of unnecessary invasive procedures. A recognition of sonographic findings associated with pregnancy progression and complications such as tubal or uterine rupture, severe hemorrhage, septic abortion, and development of arteriovenous communications ensures prompt patient surgical management. The authors discuss the use of MTX in the treatment of disorders arising from trophoblastic tissue (namely EP and GTD), its mechanism of action, its route of administration, and various treatment regimens. The authors also provide a focused discussion of the role of US in the detection and diagnosis of EP and GTD, the assessment of the eligibility criteria for MTX use, and the identification of the sonographic findings seen following MTX treatment, with specific emphasis on imaging findings associated with MTX treatment success and failure. Online supplemental material is available for this article. ©RSNA, 2021.

Multimodality Imaging Evaluation of Fetal Spine Anomalies with Postnatal Correlation.

Congenital anomalies of the spine are associated with substantial morbidity in the perinatal period and may affect the rest of the patient's life. Accurate early diagnosis of spinal abnormalities during fetal imaging allows prenatal, perinatal, and postnatal treatment planning, which can substantially affect functional outcomes. The most common and clinically relevant congenital anomalies of the spine fall into three broad categories: spinal dysraphism, segmentation and fusion anomalies of the vertebral column, and sacrococcygeal teratomas. Spinal dysraphism is further categorized into one of two subtypes: open spinal dysraphism and closed spinal dysraphism. The latter category is further subdivided into those with and without subcutaneous masses. Open spinal dysraphism is an emergency and must be closed at birth because of the risk of infection. In utero closure is also offered at some fetal centers. Sacrococcygeal teratomas are the most common fetal pelvic masses and the prognosis is variable. Finally, vertebral body anomalies are categorized into formation (butterfly and hemivertebrae) and segmentation (block vertebrae) anomalies. Although appropriate evaluation of the fetal spine begins with US, which is the initial screening modality of choice, MRI is increasingly important as a problem-solving tool, especially given the recent advances in fetal MRI, its availability, and the complexity of fetal interventions. Online supplemental material is available for this article. ©RSNA, 2021.

An Algorithmic Approach to Complex Fetal Abdominal Wall Defects.

OBJECTIVE. The purpose of this article is to describe the imaging findings associated with complex fetal abdominal wall defects and provide an algorithmic method for arriving at a final diagnosis. CONCLUSION. Fetal ventral abdominal wall defects are a complex group of conditions with a broad spectrum of associated multisystem anomalies and manifestations. Correct characterization and classification of these defects require not only familiarity with imaging findings but also a systematic approach to avoid diagnostic confusion.

Imaging Evaluation of Fallopian Tubes and Related Disease: A Primer for Radiologists.

A wide range of benign and malignant processes can affect one or both fallopian tubes. Familiarity with and recognition of the characteristic imaging features of these diseases and conditions are imperative for accurate diagnosis and prompt patient management. Disorders including pelvic inflammatory disease (hydrosalpinx and pyosalpinx in particular), isolated tubal torsion and ovarian torsion with fallopian tube involvement, endometriosis manifesting as hematosalpinx and adhesions, ectopic pregnancy, and malignancies are the most important entities that radiologists should be familiar with when assessing the fallopian tubes. Some fallopian tube diseases are self-limiting, while others can result in infertility or even potentially life-threatening infection or bleeding if left untreated. Therefore, correct diagnosis is important for appropriate life-saving treatment and preserving fertility. Understanding the physiologic features of the fallopian tube and the role of this organ in the pathogenesis of pelvic neoplasms is equally important. Knowledge of what to expect in a patient who has undergone uterine and fallopian tube interventions, such as uterine ablation and fallopian tube ligation, and of the potential associated complications (eg, postablation sterilization syndrome) also is pertinent. The imaging modalities used for the evaluation of fallopian tube disease and patency range from commonly used examinations such as US, CT, and MRI to other modalities such as hysterosalpingography and hysterosonography performed by using US contrast material. The ability to differentiate fallopian tube conditions from other adnexal and pelvic pathologic entities by using a variety of imaging modalities allows the radiologist to make a timely diagnosis and ensure proper clinical management. Online supplemental material is available for this article. ©RSNA, 2020.

Imaging Evaluation of Abdominopelvic Gunshot Trauma.

Firearm-related injuries, or gunshot wounds (GSWs), are among the most important worldwide public health problems, resulting in considerable annual morbidity, disability, and mortality. GSWs to the abdomen and pelvis are associated with substantial injuries to multiple organs and tissues. Imaging plays an important role in identifying these injuries, dictating nonoperative management, and determining imaging and clinical follow-up, as well as helping manage potential long-term complications. CT is the primary imaging modality used to evaluate these injuries and their complications, including use of reconstructed multiplanar volume-rendered images. The authors discuss the ballistics and mechanisms of firearm injury, CT findings, trajectory analysis, and applications of different imaging modalities above and beyond CT in evaluation of GSWs. Imaging findings and classifications of the severity of injuries to solid and hollow organs and vascular, musculoskeletal, and neurologic systems are reviewed. Key complications associated with gunshot injuries to the abdomen and pelvis are presented. The challenges of imaging in the acute trauma setting and potential pitfall mimics at imaging, particularly at CT, are also described. A step-by-step guide for thorough and comprehensive evaluation of GSWs to the abdomen and pelvis is introduced, with tips for optimizing effective communication with the clinical team. Online supplemental material is available for this article. ©RSNA, 2020.