Imaging of Antepartum and Postpartum Hemorrhage.

Severe obstetric hemorrhage is a leading cause of maternal mortality and morbidity worldwide. Major hemorrhage in the antepartum period presents potential risks for both the mother and the fetus. Similarly, postpartum hemorrhage (PPH) accounts for up to a quarter of maternal deaths worldwide. Potential causes of severe antepartum hemorrhage that radiologists should be familiar with include placental abruption, placenta previa, placenta accreta spectrum disorders, and vasa previa. Common causes of PPH that the authors discuss include uterine atony, puerperal genital hematomas, uterine rupture and dehiscence, retained products of conception, and vascular anomalies. Bleeding complications unique to or most frequently encountered after cesarean delivery are also enumerated, including entities such as bladder flap hematomas, rectus sheath and subfascial hemorrhage, and infectious complications of endometritis and uterine dehiscence. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material. See the invited commentary by Javitt and Madrazo in this issue.

Benign and Malignant Ovarian Teratomas: Multimodality Imaging Findings With Histopathologic Correlation.

ABSTRACT: The purpose of this article is to provide a comprehensive review of the imaging findings along with histopathologic correlation of mature (benign) teratomas and malignant ovarian teratomas, which include both immature teratomas and malignant degeneration of mature teratomas. The radiologist's ability to provide an accurate diagnosis plays an essential role in guiding the interdisciplinary care of patients with malignant teratomas and improving their outcomes.

Radiological and pathological assessment with EOB-MRI after Y90 radiation lobectomy prior to liver resection for hepatocellular carcinoma.

BACKGROUND: Radiation lobectomy (RL) utilizes Yttrium-90 (Y90) radioembolization for achieving tumor control and inducing contralateral lobe hypertrophy. Our objective was to evaluate the chronological changes occurring radiologically and histopathologically after Y90 RL. METHODS: We retrospectively reviewed 22 patients with chronic liver disease who underwent Y90 RL prior to planned liver resection for hepatocellular carcinoma. Gadolinium ethoxybenzyl diethylenetriamine penta-acetic acid (Gd-EOB-DTPA) enhanced magnetic resonance imaging (EOB-MRI) was performed every 3 months. RESULTS: Future liver remnant volume (FLRV) significantly increased up to 9 months after Y90 RL. Gd-EOB-DTPA uptake in the treated lobe experienced a 40% reduction in enhancement ratio (ER) during ensuing first 3 months, and never recovered. The reduced ER in the non-tumoral parenchyma was significantly correlated with increased FLRV and FLR (r = 0.41 and r = 0.35, respectively; both p < 0.01). Histopathological evaluation of non-tumor liver tissue found features of sinusoidal obstruction syndrome as an early change after Y90 RL (median 5.7 months) and parenchymal collapse as a late change (mean 11 months). DISCUSSION: The reduced uptake of Gd-EOB-DTPA at 3 months post Y90 RL correlates with a significant increase in FLRV prior to liver resection. EOB-MRI evaluation at 3 months can guide future plan of action after Y90 RL.

Consensus Definitions and Interpretation Templates for Magnetic Resonance Imaging of Defecatory Pelvic Floor Disorders: Proceedings of the Consensus Meeting of the Pelvic Floor Disorders Consortium of the American Society of Colon and Rectal Surgeons, the Society of Abdominal Radiology, the International Continence Society, the American Urogynecologic Society, the International Urogynecological Association, and the Society of Gynecologic Surgeons.

The Pelvic Floor Disorders Consortium (PFDC) is a multidisciplinary organization of colorectal surgeons, urogynecologists, urologists, gynecologists, gastroenterologists, radiologists, physiotherapists, and other advanced care practitioners. Specialists from these fields are all dedicated to the diagnosis and management of patients with pelvic floor conditions, but they approach, evaluate, and treat such patients with their own unique perspectives given the differences in their respective training. The PFDC was formed to bridge gaps and enable collaboration between these specialties. The goal of the PFDC is to develop and evaluate educational programs, create clinical guidelines and algorithms, and promote high quality of care in this unique patient population. The recommendations included in this article represent the work of the PFDC Working Group on Magnetic Resonance Imaging of Pelvic Floor Disorders (members listed alphabetically in Table 1). The objective was to generate inclusive, rather than prescriptive, guidance for all practitioners, irrespective of discipline, involved in the evaluation and treatment of patients with pelvic floor disorders.

Imaging Evaluation of Living Liver Donor Candidates: Techniques, Protocols, and Anatomy.

The need for liver transplants is increasing because the prevalence of liver diseases and the indications for transplants are growing. In response to the shortage of grafts from deceased donors, more transplants are being performed worldwide with grafts from living donors. Radiologic evaluation is an integral component in the assessment of donor candidates to ensure their eligibility and to choose the most appropriate surgical approach. MRI is the preferred modality for evaluation of the liver parenchyma and biliary tree. In most centers, a combination of MRI and CT is used to take advantage of the higher spatial resolution of CT for evaluation of arteries. However, MRI-only assessment is feasible. In addition to assessment of the liver parenchyma for abnormalities such as steatosis, a detailed evaluation of the hepatic vascular and biliary system for pertinent anatomic variants is crucial, because these variants can affect surgical techniques and outcomes in both recipients and donors. In this pictorial article, after a brief review of the most common surgical techniques and postsurgical liver anatomy, the biliary and vascular anatomy are discussed, with specific attention paid to the variants that are pertinent to this surgical procedure. The roles of liver segmentation and volumetric assessment and current imaging techniques and protocols are also discussed. Online supplemental material is available for this article. ©RSNA, 2021.

Society of Abdominal Radiology (SAR) and European Society of Urogenital Radiology (ESUR) joint consensus statement for MR imaging of placenta accreta spectrum disorders.

OBJECTIVES: This study was conducted in order to establish the joint Society of Abdominal Radiology (SAR) and European Society of Urogenital Radiology (ESUR) guidelines on placenta accreta spectrum (PAS) disorders and propose strategies to standardize image acquisition, interpretation, and reporting for this condition with MRI. METHODS: The published evidence-based data and the opinion of experts were combined using the RAND-UCLA Appropriateness Method and formed the basis for these consensus guidelines. The responses of the experts to questions regarding the details of patient preparation, MRI protocol, image interpretation, and reporting were collected, analyzed, and classified as "recommended" versus "not recommended" (if at least 80% consensus among experts) or uncertain (if less than 80% consensus among experts). RESULTS: Consensus regarding image acquisition, interpretation, and reporting was determined using the RAND-UCLA Appropriateness Method. The use of a tailored MRI protocol and standardized report was recommended. CONCLUSIONS: A standardized imaging protocol and reporting system ensures recognition of the salient features of PAS disorders. These consensus recommendations should be used as a guide for the evaluation of PAS disorders with MRI. KEY POINTS: • MRI is a powerful adjunct to ultrasound and provides valuable information on the topography and depth of placental invasion. • Consensus statement proposed a common lexicon to allow for uniformity in MRI acquisition, interpretation, and reporting of PAS disorders. • Seven MRI features, namely intraplacental dark T2 bands, uterine/placental bulge, loss of low T2 retroplacental line, myometrial thinning/disruption, bladder wall interruption, focal exophytic placental mass, and abnormal vasculature of the placental bed, reached consensus and are categorized as "recommended" for diagnosing PAS disorders.

Hypo-vascular hepatocellular carcinoma and liver transplantation: Morphological characteristics and implications on outcomes.

BACKGROUND: The clinical importance of hypovascular liver lesions in cirrhotic patients awaiting liver transplantation (LT) has not been fully investigated. The objective of this study was to characterize the clinicopathologic features and management of these tumors and to assess their impact on post-LT outcomes. METHODS: We performed a retrospective review of cirrhotic patients with lesions suspicious for hypovascular hepatocellular carcinoma (HCC) who underwent LT at a single institution from 2011- 2017. RESULTS: We identified 22 pre-LT patients with radiologic diagnosis of a lesion(s) suspicious for hypovascular HCC. There were 28 hypovascular lesions within the 22 patient cohort; 9 lesions (32%) converted to hypervascular HCC before LT and 19 lesions remained hypovascular at LT. 88% of hypovascular lesions were HCC on explant pathology. Compared to patients with hyper-vascular HCC lesions, hypovascular HCC lesions underwent less preoperative tumor ablation (58% vs 89%; P < .01). Hypovascular HCC were more likely to be well-differentiated (67% vs 11%; P < .01), but there were no differences in the microvascular invasion, tumor recurrence, or survival post-LT. CONCLUSIONS: Hypovascular HCC has similar clinical outcomes and needs for transplantation as hypervascular HCC. The high prevalence of HCC within suspicious hypovascular lesions supports a similar monitoring and locoregional therapy strategy as for hypervascular HCC.

Bosniak IIF and III Renal Cysts: Can Apparent Diffusion Coefficient-Derived Texture Features Discriminate Between Malignant and Benign IIF and III Cysts?

OBJECTIVE: The aim of this study was to determine which apparent diffusion coefficient-derived texture features are associated with malignancy in Bosniak IIF and III renal cystic lesions. METHODS: Twenty benign and 7 malignant Bosniak IIF (22) or III (5) renal cysts, as evaluated with magnetic resonance imaging, were assessed for progression to pathology-confirmed malignancy. Whole-cyst volumes of interest were manually segmented from apparent diffusion coefficient maps. Texture features were extracted from each volume of interest, including first-order histogram-based features and higher-order features, and data were analyzed with the Mann-Whitney U test to predict malignant progression. RESULTS: Eleven of 17 first-order features were significantly greater in benign compared with malignant cysts. Eight higher-order gray-level co-occurrence matrix (GLCM) texture features were significantly different between groups, 5 of which were greater in the benign population. CONCLUSIONS: Apparent diffusion coefficient-derived texture measures may help differentiate between benign and malignant Bosniak IIF and III cysts.

Prenatal sonography of multicentric infantile myofibromatosis: Case report and review of the literature.

Scant literature exists on prenatally diagnosed infantile myofibromatosis (IM). We report a case of multicentric IM, which was first recognized as a soft-tissue paraspinal mass on prenatal sonography and subsequently characterized by MRI with pathological confirmation.

Diffusion-weighted imaging of the liver in patients with chronic liver disease: comparison of monopolar and bipolar diffusion gradients for image quality and lesion detection.

OBJECTIVE: The objective of our study was to compare diffusion-weighted imaging (DWI) sequences using a bipolar versus a monopolar single-shot echo-planar imaging (EPI) gradient design for image quality and for lesion detection and characterization in patients with liver disease. MATERIALS AND METHODS: In this retrospective study, 77 patients with chronic liver disease who underwent MRI including bipolar and monopolar DWI at 1.5 T were assessed. Two independent observers reviewed the DWI studies for image quality and the detection and characterization of liver lesions. The reference standard for diagnosis was established by consensus review of two different observers using imaging characteristics on conventional MRI sequences, lesion stability over time, pathologic correlation, or a combination of these findings. The estimated signal-to-noise ratio (SNR) of liver parenchyma and apparent diffusion coefficients (ADCs) of the liver and lesions were calculated for both sequences. ROC analysis was conducted to evaluate the performance of ADC for the diagnosis of hepatocellular carcinoma (HCC). RESULTS: Eighty-five lesions, 50 HCCs and 35 benign lesions, were detected with the reference standard in 38 patients. There was equivalent image quality for the bipolar and monopolar sequences (p = 0.24-0.42). The HCC detection rate for observers 1 and 2 was slightly better with bipolar DWI (50.0% and 52.0%, respectively) compared with monopolar DWI (44.0% and 46.0%); however, this difference did not reach statistical significance. The estimated SNR was higher with the monopolar sequence than with the bipolar sequence (p ≤ 0.001). The AUC for the ROC curve was 0.691 for bipolar DWI and 0.649 for monopolar DWI when ADC was used for the characterization of HCC, which is not a statistically significant difference (p = 0.59). CONCLUSION: The higher estimated SNR yielded by the monopolar DWI sequence did not translate into better HCC detection compared with the bipolar DWI sequence. ADC has a limited role for HCC characterization in patients with liver disease.

Epstein-Barr virus-associated smooth muscle tumors in children following solid organ transplantation: a review.

EBV-SMT are a rare entity following organ transplantation. Given the rarity of the tumor, there is no standard approach to diagnosis and treatment. A literature search identified 28 reported cases of EBV-SMT in addition to our own experience with one case. The aim of this review is to summarize the existing data regarding pathogenesis, diagnosis, and treatment.

Implementation of Medical Students as Radiology Reading Room Coordinators.

OBJECTIVE: Effort has been made to minimize the burden of non-interpretive tasks (NITs), in particular by hiring and training non-radiologist support staff as reading room coordinators (RRCs). Our medical center recruited and trained senior medical students from our affiliated school of medicine to work alongside on-call radiology residents as RRCs. METHODS: A 12-month Malpractice Carrier monetary grant was acquired to fund medical students at with the aim to reduce malpractice risk. After the first year, residents were surveyed regarding the impact of the RRCs on perceived on-call efficiency and morale. Furthermore, report turnaround times (TAT) on call shifts that were and were not accompanied by a RRC were compared. RESULTS: 89 % of residents strongly agreed that the RRC improved workflow efficiency, decreased distractions, and felt less stressed during the call shift when the RRC was on duty. 78 % strongly agreed to be more likely to contact a referring clinician when the RRC was able to help coordinate. The mean TAT in the presence of a RRC was 36.8 min, and the mean TAT in the absence of a RRC was 36.9 min DISCUSSION: After hiring medical students to assist on-call radiology residents with noninterpretive tasks, residents reported subjective indicators of program success, but average report turnaround time was unaffected. Nevertheless, we predict that this type of program will continue to grow among academic radiology departments, though additional research is required to evaluate national trends and impacts on radiologist productivity and well-being.

The Impact of an Artificial Intelligence Certificate Program on Radiology Resident Education.

RATIONALE AND OBJECTIVES: The objective of this study was to evaluate the effectiveness of a pilot artificial intelligence (AI) certificate program in aiding radiology trainees to develop an understanding of the evolving role and application of artificial intelligence in radiology. A secondary objective was set to determine the background of residents that would most benefit from such training. MATERIALS AND METHODS: This was a prospective pilot study involving 42 radiology residents at two separate residency programs who participated in the Radiological Society of North America Imaging AI Foundational Certificate course over a four-month period. The course consisted of 6 online modules that contained didactic lectures followed by end-of-module quizzes to assess knowledge gained from these lectures. Pre- and post-course assessments were conducted to evaluate the residents' knowledge and skills in AI. Additionally, a post-course survey was performed to assess participants' overall satisfaction with the course. RESULTS: All participating residents completed the certificate program. The mean pre-course assessment score was 37 %, which increased to 73 % after completing the modules (p < 0.001). 74 % (31/42) endorsed the belief the course improved familiarity with artificial intelligence in radiology. Residency program, residency year, and reported prior familiarity with AI were not found to influence pre-course score, post-course score, nor score improvement. 57 % (24/42) endorsed interest in pursuing further certification in AI. CONCLUSION: Our pilot study suggests that a certificate course can effectively enhance the knowledge and skills of radiology residents in the application of AI in radiology. The benefits of such a course can be found regardless of program, resident year, and self-reported prior resident understanding of radiology in AI.

Cancer in pregnancy: treatment effects.

PURPOSE: Pregnant patients present a unique challenge to cancer therapy. Due to the potential catastrophic implications related to teratogenic effects or pregnancy loss, oncologic management of this vulnerable patient group must be strategic and personalized. METHODS: This article will discuss the unique treatment approach to the pregnant cancer patient. This includes discussion of the role of imaging during staging, treatment, and follow-up with an emphasis on avoiding ionizing radiation when possible. RESULTS AND CONCLUSION: Specific considerations and modifications to standard cancer treatments, including surgery and systemic therapies such as chemotherapy, immunotherapy, targeted and hormone therapies are crucial components of providing oncologic care to minimize negative effects to the mother and developing fetus. Radiation and proton therapy are also options that may be employed in specific circumstances. Finally, this article will address the long-term treatment effects of these therapies on future fertility.

Prognosis, counseling, and indications for termination of pregnancy.

As the coincidence of pregnancy and cancer rise, clinicians must be prepared to counsel their patients on the complex relationship between maternal and fetal health. In most types of cancer, maternal prognosis mirrors that of non-pregnant women. However, challenges associated with the timing of diagnosis and treatment can present additional risks. Consequently, pregnant cancer patients must be counseled early and effectively with regard to how their pregnancy status affects treatment options and the range of expected outcomes for both mother and fetus. Some patients choose to terminate pregnancy after such counseling, though the specific course of action depends on the cancer in question, the stage at diagnosis, and the personal priorities and values of the patient.

Imaging and clinical assessment of functional defecatory disorders with emphasis on defecography.

Functional defecation disorders (FDD) encompass causes of constipation associated with anorectal dysfunction, which include dyssynergia or inadequate defecatory propulsion. FDD are frequently encountered in clinical practice and may affect up to 33-50% of patients with chronic constipation. The etiology of FDD is unclear, however, it has been defined as an acquired, but subliminal behavioral disorder. Pathophysiologic mechanisms may include discoordination of rectoanal muscles, paradoxical contraction or insufficient relaxation of puborectalis and/or anal sphincter during defecation, and sluggish colonic transit. A combination of comprehensive clinical assessment, digital rectal examination and a battery of physiologic tests are needed to make an accurate diagnosis of FDD. Defecography may play a crucial role in the evaluation of FDD, especially when a balloon expulsion test (BET) and/or anorectal manometry (ARM) are equivocal or demonstrate contradictory results. In this review, we provide a thorough overview of the epidemiology, pathophysiology, diagnostic criteria, clinical and imaging evaluation, and treatment options for FDD, with an emphasis on available diagnostic imaging tools such as defecography and conventional fluoroscopic methods.

Peripheral arterial occlusion due to COVID-19: CT angiography findings of nine patients.

BACKGROUND: Reports have indicated an association of large vessel peripheral arterial occlusion in the setting of Coronavirus Disease 2019 (COVID-19). While prior investigations have mostly focused on venous or cerebral arterial occlusions, we examined patients presenting exclusively with peripheral arterial extremity occlusions to investigate for any predisposing factors in this subset of COVID-19 patients. MATERIALS AND METHODS: This is a retrospective study of COVID-19 patients with peripheral arterial occlusions presenting to a multi-hospital health care system in New York City between February 1st, 2020 and April 30th, 2020. Patient data and computed tomography angiography (CTA) exams in this subset were then collected and analyzed. RESULTS: For the months of February, March, and April 2020, we identified 9 patients (ages 37-93 yrs) at our health care system who underwent extremity CTA for large vessel upper or lower extremity arterial occlusion and were diagnosed with COVID-19. Patient medical histories and clinical parameters were evaluated to identify common risk factors including obesity, hypertension, hyperlipidemia, and diabetes. Patients presented with increased inflammatory markers including ferritin, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) as well as increased D-dimer. CONCLUSION: Our findings suggest patients with COVID-19 and comorbidities presenting with elevated inflammatory markers and D-dimer may be at increased risk of large vessel peripheral arterial occlusion.

Assessing locoregional treatment response to Hepatocellular Carcinoma: comparison of hepatobiliary contrast agents to extracellular contrast agents.

Cross-sectional imaging with contrast-enhanced magnetic resonance imaging (MRI) is routinely performed in patients with hepatocellular carcinoma (HCC) to assess tumor response to locoregional therapy (LRT). Current response assessment algorithms, such as the Liver Imaging Reporting and Data System (LI-RADS) treatment response algorithm (TRA), allow assessment using conventional gadolinium-based extracellular contrast agents (ECA) for accurate tumor response assessment following LRT. MRI with hepatobiliary agents (HBA) allows an acquisition of hepatobiliary phase (HBP), which is proven to increase sensitivity for detection of observations in at-risk patients, particularly for findings < 2 cm. The use of HBA is not yet incorporated into the TRA; however, it is increasingly used in clinical practice. Few published studies have evaluated the performance of LI-RADS TRA by applying ancillary features related to HBP that has resulted in category adjustment, enabling more sensitive and unequivocal diagnosis. This may help timely management of viable cases, without a significant loss of specificity in comparison with the ECA-based LI-RADS TRA assessment. In this review, we will describe and compare the imaging appearance of treated HCC on MRI using extracellular and hepatobiliary contrast agents and discuss emerging evidence and pitfalls in the assessment of tumor response following LRT with HBA.