Safety of Contrast Material Use During Pregnancy and Lactation

Approach to Altered Mental Status in Pregnancy and Postpartum

The evaluation and diagnosis of altered mental status in the pregnant or postpartum patient largely parallels the approach used for any other patient; however, there are several critical differences including that some neuroobstetric diagnoses require emergent delivery of the fetus. Being familiar with the physiological changes and medical complications of pregnancy and delivery is therefore essential. This review first addresses pregnancy-specific disorders that may result in altered mental status, such as the hypertensive disorders of pregnancy and pregnancy-related metabolic and endocrinopathies. The focus then shifts to the complex physiologic changes in pregnancy and how these changes contribute to the distinct epidemiology of pregnancy-related cerebrovascular complications like intracranial hemorrhage, ischemic stroke, and reversible cerebral vasoconstriction syndrome. Medical disorders that are not unique to pregnancy, such as infections and autoimmune conditions, may present de novo or worsen during pregnancy and the peripartum period and require a thoughtful approach to diagnosis and management. Finally, the unique nervous system complications of obstetric anesthesia are explored. In each section, there is a focus not only on diagnosis and syndrome recognition but also on the emergent treatment needed to reverse these complications, bearing in mind the unique physiology of the pregnant patient.

Use of gadolinium-based contrast agents in multiple sclerosis: a review by the ESMRMB-GREC and ESNR Multiple Sclerosis Working Group

Magnetic resonance imaging (MRI) is the most sensitive technique for detecting inflammatory demyelinating lesions in multiple sclerosis (MS) and plays a crucial role in diagnosis and monitoring treatment effectiveness, and for predicting the disease course. In clinical practice, detection of MS lesions is mainly based on T2-weighted and contrast-enhanced T1-weighted sequences. Contrast-enhancing lesions (CEL) on T1-weighted sequences are related to (sub)acute inflammation, while new or enlarging T2 lesions reflect the permanent footprint from a previous acute inflammatory demyelinating event. These two types of MRI features provide redundant information, at least in regular monitoring of the disease. Due to the concern of gadolinium deposition after repetitive injections of gadolinium-based contrast agents (GBCAs), scientific organizations and regulatory agencies in Europe and North America have proposed that these contrast agents should be administered only if clinically necessary. In this article, we provide data on the mode of action of GBCAs in MS, the indications of the use of these agents in clinical practice, their value in MS for diagnostic, prognostic, and monitoring purposes, and their use in specific populations (children, pregnant women, and breast-feeders). We discuss imaging strategies that achieve the highest sensitivity for detecting CELs in compliance with the safety regulations established by different regulatory agencies. Finally, we will briefly discuss some alternatives to the use of GBCA for detecting blood-brain barrier disruption in MS lesions. CLINICAL RELEVANCE STATEMENT: Although use of GBCA at diagnostic workup of suspected MS is highly valuable for diagnostic and prognostic purposes, their use in routine monitoring is not mandatory and must be reduced, as detection of disease activity can be based on the identification of new or enlarging lesions on T2-weighted images. KEY POINTS: • Both the EMA and the FDA state that the use of GBCA in medicine should be restricted to clinical scenarios in which the additional information offered by the contrast agent is required. • The use of GBCA is generally recommended in the diagnostic workup in subjects with suspected MS and is generally not necessary for routine monitoring in clinical practice. • Alternative MRI-based approaches for detecting acute focal inflammatory MS lesions are not yet ready to be used in clinical practice.

Using MRI appendicitis scale and DWI for the diagnosis of acute appendicitis in pregnant women

OBJECTIVES

To assess the performance of MRI scale for the diagnosis of acute appendicitis in pregnant women and to determine the added diagnostic value of diffusion-weighted imaging (DWI).

METHODS

From January 2018 to December 2020, 80 patients were included. All MRI were performed with a 1.5-Tesla scanner with anterior array body coil. This analysis included (1) T2-weighted imaging (T2WI), (2) fat-saturated T2WI, and (3) DWI. Two radiologists blinded to the diagnosis recorded their assessment of four findings: appendiceal diameter, appendiceal wall thickness, luminal mucus, and periappendiceal inflammation. The MRI scale of acute appendicitis which ranged from 0 to 4 was determined from these factors. An additional one point was added to the MRI appendicitis scale in those patients with evidence of appendiceal restricted diffusion on DWI. The diagnostic values and predictive factors were computed.

RESULTS

Multivariate analysis demonstrated that the calculated MRI appendicitis scale was a significant independent predictor of acute appendicitis with a sensitivity of 96.6%, specificity of 90.2%, and PPV of 84.8%. The odds ratio of appendicitis is increased by 22.3 times for every increase in one point on the MRI appendicitis scale. Therefore, the addition of one point for restricted diffusion in the appendix on DWI imaging can add substantial value, both positive and negative predictive value, towards making an accurate diagnosis of acute appendicitis.

CONCLUSIONS

MRI appendicitis scale is an objective and significant independent predictive factor for acute appendicitis in pregnant women. Incorporation of diffusion weighted imaging to MRI can improve diagnosis of acute appendicitis.

CLINICAL RELEVANCE STATEMENT

MRI appendicitis scale is an objective and significant independent predictor of acute appendicitis in pregnant women. Incorporation of DWI/ADC map to MRI examinations can improve diagnosis of acute appendicitis in pregnant women.

KEY POINTS

• MRI appendicitis scale is an objective and significant independent predictive factor for acute appendicitis in pregnant women. • The odds ratio of appendicitis can be increased by 22.3 times for every increase of one unit in MRI scale. • Incorporation of diffusion-weighted imaging to MRI examinations can add value to the scale (4.2 ± 0.7 vs. 0.7 ± 1.1; p < 0.001) among pregnant women with appendicitis versus pregnant women without appendicitis.

Fetal Dose Evaluation for Pregnant Patients on Leksell Gamma Knife Perfexion/Icon

INTRODUCTION

It is a normal procedure to avoid the application of ionizing radiation during pregnancy. In very rare occasions, treatment can be performed, but doses to the fetus must be evaluated and reported, and the patient must sign informed consent. There can occur two types of damage caused by ionizing radiation - deterministic and stochastic effects. Deterministic effects may occur after reaching a certain threshold (100 mGy for this study); meanwhile, stochastic effects have no limit and their probability rises with dose. This study focuses on deterministic effects.

CASE PRESENTATIONS

This study compares the dose measured on phantom for the area of the pelvis and the dose measured on 3 patients with dosimeters positioned on the pelvis irradiated on Leksell Gamma Knife Perfexion/Icon. The mean dose for measurement on phantom for the pelvis was 0.73 ± 0.76 mGy, and for the patients, it was 1.28 mGy, 0.493 mGy, and 0.549 mGy which is 80 times lower, 200 times lower, and 180 times lower than the threshold for deterministic effects, respectively.

CONCLUSION

The measurement carried on phantom served as the base for drafting informed consent and provided initial proof that treatment can be safely delivered. Measurements performed on patients only confirmed that irradiation of pregnant patients on Leksell Gamma Knife Perfexion/Icon is safe relative to the deterministic effects. Nevertheless, pregnant patients should be treated with ionizing radiation only in very extraordinary situations.

A review of contrast-enhanced ultrasound using SonoVue® and Sonazoid™ in non-hepatic organs

Contrast-enhanced ultrasound (CEUS) is a dependable modality for the diagnosis of various clinical conditions. A judicious selection of ultrasound contrast agent (UCA) is imperative for optimizing imaging and improving diagnosis. Approved UCAs for imaging the majority of organs include SonoVue, a pure blood agent, and Sonazoid, which exhibits an additional Kupffer phase. Despite the fact that the two UCAs are increasingly being employed, there is a lack of comparative reviews between the two agents in different organs diseases. This review represents the first attempt to compare the two UCAs in non-hepatic organs, primarily including breast, thyroid, pancreas, and spleen diseases. Through comparative analysis, this review provides a comprehensive and objective evaluation of the performance characteristics of SonoVue and Sonazoid, with the aim of offering valuable guidance for the clinical application of CEUS. Overall, further clinical evidences are required to compare and contrast the dissimilarities between the two UCAs in non-hepatic organs, enabling clinicians to make an appropriate selection based on actual clinical applications.

Acute headache in pregnant and post-partum patients: A clinical review

BACKGROUND

Headaches during pregnancy and the post-partum period may be due to either an exacerbation of a pre-existing neurological presentation, a new pregnancy-related process, or a non-pregnancy related condition. Key physiologic changes during pregnancy and the post-partum period contribute to the vulnerability of this patient population and the increased risk of complications.

OBJECTIVE OF THE REVIEW

Review causes of headaches in pregnant and post-partum patients as well as neuroimaging techniques performed.

DISCUSSION

Headaches are a common complaint for pregnant and post-partum patients. For pregnant patients, a range of serious causes must be considered including cerebral venous thrombosis, posterior reversible encephalopathy syndrome and stroke. Primary headaches are responsible for most post-partum headaches, however other causes also include pre-clampsia, cerebral venous thrombosis and post-dural headache. Determining the optimal imaging technique in this vulnerable population remains a challenge given the scarce guidelines.

CONCLUSION

The greatest difficulty while evaluating pregnant and post-partum patients presenting with an acute headache in an emergency setting is to determine whether the headache is due to a primary disorder such as migraines or is secondary to an underlying, sometimes serious pathology. The following review explores evidenced-based diagnosis of headache in this particular setting.

Imaging of Acute Abdominopelvic Pain in Pregnancy and Puerperium-Part I: Obstetric (Non-Fetal) Complications

Acute abdominopelvic pain in pregnant and postpartum patients presents clinical and therapeutic challenges, often requiring quick and accurate imaging diagnosis. Ultrasound remains the primary imaging investigation. Magnetic resonance imaging (MRI) has been shown to be a powerful diagnostic tool in the setting of acute abdominal pain during pregnancy and puerperium. MRI overcomes some drawbacks of US, avoiding the ionizing radiation exposure of a computed tomography (CT) scan. Although CT is not usually appropriate in pregnant patients, it is crucial in the emergency evaluation of postpartum complications. The aim of this article is to provide radiologists with a thorough familiarity with the common and uncommon pregnancy and puerperium abdominal emergencies by illustrating their imaging appearances. The present first section will review and discuss the imaging findings for acute abdominopelvic pain of obstetric (non-fetal) etiology.

A State-of-the-Science Review on Metal Biomarkers

PURPOSE OF REVIEW

Biomarkers are commonly used in epidemiological studies to assess metals and metalloid exposure and estimate internal dose, as they integrate multiple sources and routes of exposure. Researchers are increasingly using multi-metal panels and innovative statistical methods to understand how exposure to real-world metal mixtures affects human health. Metals have both common and unique sources and routes of exposure, as well as biotransformation and elimination pathways. The development of multi-element analytical technology allows researchers to examine a broad spectrum of metals in their studies; however, their interpretation is complex as they can reflect different windows of exposure and several biomarkers have critical limitations. This review elaborates on more than 500 scientific publications to discuss major sources of exposure, biotransformation and elimination, and biomarkers of exposure and internal dose for 12 metals/metalloids, including 8 non-essential elements (arsenic, barium, cadmium, lead, mercury, nickel, tin, uranium) and 4 essential elements (manganese, molybdenum, selenium, and zinc) commonly used in multi-element analyses.

RECENT FINDINGS

We conclude that not all metal biomarkers are adequate measures of exposure and that understanding the metabolic biotransformation and elimination of metals is key to metal biomarker interpretation. For example, whole blood is a good biomarker of exposure to arsenic, cadmium, lead, mercury, and tin, but it is not a good indicator for barium, nickel, and uranium. For some essential metals, the interpretation of whole blood biomarkers is unclear. Urine is the most commonly used biomarker of exposure across metals but it should not be used to assess lead exposure. Essential metals such as zinc and manganese are tightly regulated by homeostatic processes; thus, elevated levels in urine may reflect body loss and metabolic processes rather than excess exposure. Total urinary arsenic may reflect exposure to both organic and inorganic arsenic, thus, arsenic speciation and adjustment for arsebonetaine are needed in populations with dietary seafood consumption. Hair and nails primarily reflect exposure to organic mercury, except in populations exposed to high levels of inorganic mercury such as in occupational and environmental settings. When selecting biomarkers, it is also critical to consider the exposure window of interest. Most populations are chronically exposed to metals in the low-to-moderate range, yet many biomarkers reflect recent exposures. Toenails are emerging biomarkers in this regard. They are reliable biomarkers of long-term exposure for arsenic, mercury, manganese, and selenium. However, more research is needed to understand the role of nails as a biomarker of exposure to other metals. Similarly, teeth are increasingly used to assess lifelong exposures to several essential and non-essential metals such as lead, including during the prenatal window. As metals epidemiology moves towards embracing a multi-metal/mixtures approach and expanding metal panels to include less commonly studied metals, it is important for researchers to have a strong knowledge base about the metal biomarkers included in their research. This review aims to aid metals researchers in their analysis planning, facilitate sound analytical decision-making, as well as appropriate understanding and interpretation of results.

Obstetric and Gynecologic Disorders and the Nervous System

OBJECTIVE

This article discusses obstetric and gynecologic associations with common neurologic disorders.

LATEST DEVELOPMENTS

Neurologic complications of obstetric and gynecologic disorders can arise throughout the lifespan. Caution should be exercised when prescribing fingolimod and natalizumab to patients with multiple sclerosis who are of childbearing potential because of the risk of disease rebound when they are discontinued. OnabotulinumtoxinA is considered safe in pregnancy and lactation based on long-term observational data. Hypertensive disorders of pregnancy are associated with higher subsequent cerebrovascular risk, likely via multiple mechanisms.

ESSENTIAL POINTS

Neurologic disorders may present in a variety of obstetric and gynecologic contexts, with meaningful implications for recognition and treatment. These interactions must be considered when treating women with neurologic conditions.

Acute Ischemic Stroke in Pregnancy : A Practical Focus on Neuroimaging and Reperfusion Therapy

INTRODUCTION

Pregnancy increases the risk of acute ischemic stroke (AIS) among young women and is responsible for about 5% of maternal deaths and significant disability. Concerns of potential adverse events of imaging and reperfusion therapies in this group of patients can lead to a substantial delay or omission of treatment that can significantly worsen outcomes.

OBJECTIVE

The objective of this study is to discuss main concerns of diagnosis and therapy of pregnant patients with AIS regarding neuroimaging and reperfusion treatment.

RESULTS

The cumulative radiation dose of computed tomography (CT)-based entire diagnostic procedure (noncontrast CT, CT-angiography and CT-perfusion) is estimated to be below threshold for serious fetal radiation exposure adverse events. Similarly, magnetic resonance imaging(MRI)-based imaging is thought to be safe as long as gadolinium contrast media are avoided. The added risk of intravenous thrombolysis (IVT) and mechanical thrombectomy during pregnancy is thought to be very low. Nevertheless, some additional safety measures should be utilized to reduce the risk of radiation, contrast media and hypotension exposure during diagnostic procedures or reperfusion treatment.

CONCLUSION

Fetal safety concerns should not preclude routine diagnostic work-up (except for gadolinium contrast media administration) in childbearing AIS women, including procedures applied in unknown onset and late onset individuals. Due to rather low added risk of serious treatment complications, pregnancy should not be a sole contraindication for neither IVT, nor endovascular treatment.

Role of MRI and CT in the Evaluation of Headache in Pregnancy and the Postpartum Period

Approximately 35% of acute headaches in pregnant women are secondary to an underlying condition. Headaches are also common in the postpartum period where they occur in 30% to 40% of patients. The majority of secondary headaches are due to hypertensive disorders: preeclampsia-eclampsia, posterior reversible encephalopathy syndrome, and acute arterial hypertension. Other causes include reversible cerebral vasoconstriction syndrome and pituitary apoplexy, as well as life-threatening conditions such as cerebral venous thrombosis. In this article, we review general recommendations for imaging the pregnant patients and discuss the imaging findings of common causes of headaches in pregnancy and the postpartum period.

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.

How Could Nanomedicine Improve the Safety of Contrast Agents for MRI during Pregnancy?

Pregnancy is a delicate state, during which timely investigation of possible physiological anomalies is essential to reduce the risk of maternal and fetal complications. Medical imaging encompasses different technologies to image the human body for the diagnosis, course of treatment management, and follow-up of diseases. Ultrasound (US) is currently the imaging system of choice for pregnant patients. However, sonographic evaluations can be non-effective or give ambiguous results. Therefore, magnetic resonance imaging (MRI), due to its excellent tissue penetration, the possibility of acquisition of three-dimensional anatomical information, and its high spatial resolution, is considered a valid diagnostical alternative. Nevertheless, currently employed contrast agents to improve the MRI image quality are harmful to the fetus. Because of their ability to cross the placenta, their use on pregnant patients is avoided. This review will firstly recapitulate the most common non-obstetrical, obstetrical, and fetal indications for magnetic resonance imaging on pregnant women. Fetal safety risks, due to the use of strong magnetic fields and exogenous contrast agents, will be presented. Then, possible advantages of nanostructured contrast agents compared to current molecular ones are explored. Nanosystems’ characteristics affecting contrast efficiency, and their potential for improving contrast-enhanced MRI’s safety in pregnant women, are discussed. Lastly, promising examples of nanoparticles as safer alternatives to current MRI contrast agents in pregnancy are discussed.

Maternal Stroke Associated With Pregnancy

PURPOSE OF REVIEW

This article summarizes current knowledge of the epidemiology, pathophysiology, prevention, and treatment of cerebrovascular disease in pregnant and postpartum women.

RECENT FINDINGS

Stroke is a leading cause of maternal morbidity and mortality, and most fatal strokes are preventable. Adaptive physiologic changes of pregnancy, including hemodynamic changes, venous stasis, hypercoagulability, and immunomodulation, contribute to increased maternal stroke risk. The highest-risk time period for maternal stroke is the immediate postpartum period. Migraine and hypertensive disorders of pregnancy, including gestational hypertension and preeclampsia, are major risk factors for maternal stroke. Adverse pregnancy outcomes, including gestational hypertension, preeclampsia, preterm delivery, and fetal growth restriction, are important risk factors for cerebrovascular disease later in life.

SUMMARY

Many catastrophic maternal strokes could be avoided with targeted prevention efforts, early recognition of warning signs, and rapid evaluation of neurologic symptoms. Neurologists play a central role in the care of pregnant patients with cerebrovascular disease, whether acute or chronic, and should be familiar with the unique and complex physiology of pregnancy and its complications, particularly hypertensive disorders of pregnancy.

Sonografisch assistierte venöse Thrombektomie im ersten Trimenon – ein Fallbericht

Es wird der Fall einer Patientin in der 12. Schwangerschaftswoche (SSW) mit einer deszendierenden 4-Etagen-Thrombose, welche unter konservativen stationären Maßnahmen einen Progress des Befundes erlitten hat, vorgestellt und diskutiert. Die Patientin und ihr Ehemann hatten sich trotz erhöhten Risikos für den Fötus für eine operative Rekanalisation entschieden. Die venöse Thrombektomie wurde sonografisch assistiert, ohne Anlage einer AV-Fistel, durchgeführt. Die bei Schwangeren eingeschränkten diagnostischen Möglichkeiten und Einflussfaktoren für eine Risikoevaluation für Mutter und Kind werden dargestellt.

Safety issues related to intravenous contrast agent use in magnetic resonance imaging

Gadolinium-based contrast agents (GBCAs) have been used to improve image quality of MRI examinations for decades and have an excellent overall safety record. However, there are well-documented risks associated with GBCAs and our understanding and management of these risks continue to evolve. The purpose of this review is to discuss the safety of GBCAs used in MRI in adult and pediatric populations. We focus particular attention on acute adverse reactions, nephrogenic systemic fibrosis and gadolinium deposition. We also discuss the non-GBCA MRI contrast agent ferumoxytol, which is increasing in use and has its own risk profile. Finally, we identify special populations at higher risk of harm from GBCA administration.

Intravoxel incoherent motion MR imaging analysis for diagnosis of placenta accrete spectrum disorders: A pilot feasibility study

BACKGROUND

Placenta accreta spectrum (PAS) disorders occur when the placenta adheres abnormally to the uterine myometrium and can have devastating effects on maternal health due to risks of massive postpartum hemorrhage and possible need for emergency hysterectomy. PAS can be difficult to diagnose using routine clinical imaging with ultrasound and structural MRI.

OBJECTIVE

To determine feasibility of using intravoxel incoherent motion (IVIM) magnetic resonance imaging (MRI) analysis in the diagnosis of the placenta accreta spectrum disorders in pregnant women.

METHODS

A total of 49 pregnant women were recruited including 14 with pathologically confirmed cases of PAS and 35 health controls without prior cesarean delivery and no suspected PAS by ultrasound. All women underwent diffusion-weighted imaging with an 8 b-value scanning sequence. A semi-automated method for image processing was used, creating a 3D object map, which was then fit to a biexponential signal decay curve for IVIM modeling to determine slow diffusion (D_s), fast diffusion (D_f), and perfusion fraction (P_f).

RESULTS

Our results demonstrated a high degree of model fitting (R² ≥ 0.98), with P_f significantly higher in those with PAS compared to healthy controls (0.451 ± 0.019 versus 0.341 ± 0.022, p = 0.002). By contrast, no statistical difference in the D_f (1.70 × 10^-2 ± 0.38 × 10^-2 versus 1.48 × 10^-2 ± 0.08 × 10^-2 mm²/s, p = 0.211) or D_s (1.34 × 10^-3 ± 0.10 × 10^-3 versus 1.45 × 10^-3 ± 0.007 × 10^-3 mm²/s, p = 0.215) was found between subjects with PAS and healthy controls.

CONCLUSIONS

The use of MRI, and IVIM modeling in particular, may have potential in aiding in the diagnosis of PAS when other imaging modalities are equivocal. However, the widespread use of these techniques will require generation of large normative data sets, consistent sequencing protocols, and streamlined analysis techniques.

MRI in pregnant patients with suspected abdominal and pelvic cancer: a practical guide for radiologists

The incidence of abdominal and pelvic cancer in pregnancy is low, but it is rising as the population of pregnant women gets older. Depending on disease stage, gestational age and patient's preference, active surveillance as well as surgery and chemotherapy are feasible options during pregnancy. Correct diagnosis and staging of the tumor is crucial for choosing the best therapeutic approach. Moreover, a reproducible modality to assess the treatment response is requested. Magnetic resonance imaging (MRI) is commonly used with good results for the local staging and treatment response evaluation of most abdominal and pelvic cancers in nonpregnant patients, and it is considered relatively safe during pregnancy. The purpose of this article is to analyze the most relevant topics regarding the use of MRI in pregnant women with abdominal and pelvic cancer. We discuss MRI safety during pregnancy, including the use of gadolinium-based contrast agents (GBCAs), how to prepare the patient for the exam and MRI technique. This will be followed by a brief review on the most common malignancies diagnosed during pregnancy and their MRI appearance.

Kidney Imaging and Biopsy in Pregnancy

Physiologic glomerular, tubular, and structural changes related to pregnancy may complicate the detection of underlying kidney disease in pregnant patients. Imaging studies may provide important clinical information to assist in the diagnosis and treatment of kidney disease during pregnancy. Furthermore, in select patients who develop new or worsening kidney disease in pregnancy, kidney biopsy may be essential to ensure the accuracy of diagnosis and guide treatment choices. This review article will discuss the risks and benefits of various modalities used to image the kidneys and urinary tract during pregnancy to aid in the judicious selection of appropriate imaging studies that are likely to maximize clinical benefit while minimizing fetal risk. It will also highlight the potential benefits and harms associated with antepartum kidney biopsy and will offer strategies for identifying patients who are most likely to benefit from kidney biopsy during pregnancy.

Magnetic Resonance Safety: Pregnancy and Lactation

MRI is a powerful diagnostic tool with excellent soft tissue contrast that uses nonionizing radiation. These advantages make MRI an appealing modality for imaging the pregnant patient; however, specific risks inherent to the magnetic resonance environment must be considered. MRI may be performed without and/or with intravenous contrast, which adds further fetal considerations. The risks of MRI with and without intravenous contrast are reviewed as they pertain to the pregnant or lactating patient and to the fetus and nursing infant. Relevant issues for gadolinium-based contrast agents and ultrasmall paramagnetic iron oxide particles are reviewed.

Thrombolysis and Mechanical Thrombectomy for Acute Ischemic Stroke in Pregnancy: A Case Report

Objective

Intravenous (IV) recombinant tissue plasminogen activator (rt-PA) and mechanical thrombectomy (MT) are effective treatments for acute ischemic stroke (AIS). However, the treatment for AIS in pregnancy is not established because no clinical trials have included pregnant patients. We present a case of middle cerebral artery (MCA) M2 segment occlusion in pregnancy treated with IV thrombolysis and endovascular therapy.

Case Presentation

A 36-year-old woman being 6 weeks pregnant presented with right-sided hemiparesis and aphasia. MRI showed a high-intensity area on diffusion-weighted imaging of the left parietal lobe, and MRA showed left MCA M2 segment occlusion. She underwent IV rt-PA and MT and achieved thrombolysis in cerebral infarction 2b revascularization without complications. The protein S concentration was lower than that in the physiological changes during pregnancy. She was diagnosed with embolic stroke related to coagulopathy in pregnancy, and she underwent anticoagulation. At the 3-month follow-up, the modified Rankin Scale was 0. She miscarried at 4 months, and the fetal death was presumed to be obstetric cause.

Conclusion

IV rt-PA and MT may be effective and safe treatments for pregnant patients. Estimated fetal radiation exposure during MT is low and is presumed not to affect fetal development. We should mitigate the radiation dose and reduce the dose of iodinated contrast agents, particularly in pregnant patients.

Approach to Pulmonary Arteriovenous Malformations: A Comprehensive Update

Pulmonary arteriovenous malformations (PAVMs) are abnormal direct vascular communications between pulmonary arteries and veins which create high-flow right-to-left shunts. They are most frequently congenital, usually in the setting of hereditary hemorrhagic telangiectasia (HHT). PAVMs may be asymptomatic or present with a wide variety of clinical manifestations such as dyspnea, hypoxemia, or chest pain. Even when asymptomatic, presence of PAVMs increases patients' risk of serious, potentially preventable complications including stroke or brain abscess. Transcatheter embolotherapy is considered the gold standard for treatment of PAVMs. Though previous guidelines have been published regarding the management of PAVMs, several aspects of PAVM screening and management remain debated among the experts, suggesting the need for thorough reexamination of the current literature. The authors of this review present an updated approach to the diagnostic workup and management of PAVMs, with an emphasis on areas of controversy, based on the latest literature and our institutional experience.

High-risk third trimester pregnancy with decompensated cirrhosis safely delivered following emergent preoperative interventional radiology for mitigation of variceal bleeding

Coagulopathy coupled with severe portal hypertension in the setting of cirrhosis increases the risk of mortality from variceal bleeding in pregnant women. Studies suggest transjugular intrahepatic portosystemic shunt (TIPS) creation to be a safe procedure during pregnancy in preventing variceal bleeding complications; however, it is not typically employed in severely decompensated cirrhosis. This case report of a pregnant woman presenting at 34.7 weeks' gestation demonstrates successful variceal mapping, emergent TIPS creation and variceal embolization to allow safe cesarean delivery despite severe hypofibrinogenemia and decompensated alcoholic cirrhosis. With careful medical optimization, angiographic imaging and vascular interventional radiology may be employed outside of usual indications to achieve safe pregnancy delivery and postpartum recovery.

Infección por SARS-CoV-2 en la paciente obstétrica: una perspectiva desde el cuidado crítico

La nueva infección por coronavirus (COVID-19) se constituye en el principal problema de salud pública en el mundo. Entre el 5 y el 30% de los pacientes afectados por esta enfermedad requieren manejo en una unidad de cuidado intensivo. Se han generado diferentes publicaciones con recomendaciones para la población general. Sin embargo, en la población obstétrica la evidencia científica es reducida, aún más cuando se trata de infección por COVID-19 en escenarios de cuidado intensivo obstétrico. Por esta razón, se realizó una revisión narrativa no sistemática de la literatura utilizando como fuente de información MEDLINE, sociedades científicas y los repositorios de la Organización Mundial de la Salud y el Ministerio de Salud y Protección Social de Colombia, con el objetivo de describir algunas sugerencias para el manejo de una paciente embarazada con COVID-19 en una unidad de cuidado intensivo. Se resalta que la atención debe ser realizada por un equipo interdisciplinario, bajo monitorización materna y fetal cuando corresponda, vigilando los niveles de saturación de oxígeno y la hemodinamia materna para minimizar la hipoxemia fetal. Se describen recomendaciones sobre algunos tópicos relevantes en el escenario crítico, como la intubación oportuna, la utilización adecuada de los equipos de protección personal (EPP), el manejo de la falla circulatoria, las estrategias restrictivas de fluidos y/o vasopresores, entre otros.

Ischemic stroke and cerebral venous sinus thrombosis in pregnancy

Maternal ischemic stroke and cerebral venous sinus thrombosis (CVST) are dreaded complications of pregnancy and major contributors to maternal disability and mortality. This chapter summarizes the incidence and risk factors for maternal arterial ischemic stroke (AIS) and CVST and discusses the pathophysiology of maternal AIS and CVST. The diagnosis, treatment, and secondary preventive strategies for maternal stroke are also reviewed. Special populations at high risk of maternal stroke, including women with moyamoya disease, sickle cell disease, HIV, thrombophilia, and genetic cerebrovascular disorders, are highlighted.

Pregnancy and Family Planning in Multiple Sclerosis

PURPOSE OF REVIEW

This article provides practical guidance on successful management of women with multiple sclerosis (MS) through pregnancy and the postpartum period.

RECENT FINDINGS

Recent studies indicate that most women diagnosed with MS today can have children, breast-feed, and resume beta interferons or glatiramer acetate per their preferences without incurring an increased risk of relapses during the postpartum period. More than 40% of women with mild MS do not require any treatment before conception or in the postpartum period. Women with highly active MS can now become well-controlled before, throughout, and after pregnancy via highly effective treatments. Unfortunately, pregnancy does not protect against relapses following the cessation of fingolimod or natalizumab, and some women experience severe rebound relapses during pregnancy. Accidental first-trimester exposure to teriflunomide or fingolimod increases the risk of fetal harm.

SUMMARY

Most women with MS can have normal pregnancies and breast-feed without incurring harm. Clinicians should avoid prescribing medications with known teratogenic potential (teriflunomide, fingolimod), known risk of severe rebound relapses (fingolimod, natalizumab), or unclear but plausible risks (dimethyl fumarate, alemtuzumab) to women of childbearing age who desire pregnancy or are not on reliable birth control. If a treatment needs to be resumed during breast-feeding, clinicians should opt for glatiramer acetate, interferon beta, natalizumab, or rituximab/ocrelizumab, as biologically plausible risks to the infant are exceedingly low.

Acute cardiac disease in the postpartum: What to think

A rare case of a spontaneous coronary artery dissection (SCAD) in the postpartum of a 32-year-old woman is presented. Pregnancy-related SCAD is a potentially life-threatening condition. SCAD is triggered by nonatherosclerotic disease, typically affects young-aged women and is still often underdiagnosed. Cardiac magnetic resonance is crucial to demonstrate the ischemic origin of the disease. A conservative management is generally preferred in stable SCAD as most dissected segments will heal spontaneously over a few months. Additionally, the percutaneous coronary intervention is associated with high rate of complications and procedural failure. The aim of this case was to improve awareness of SCAD and to advise clinicians seeking aid with patient management.

MRI in pregnancy: Indications and practical considerations

There is a constantly evolving knowledgebase regarding the safety of MRI in pregnant patients, as well as the safety of gadolinium administration, given potential fetal risks. This review provides an overview of national and international recommendations for patient screening and safety by trimester, evaluates the most recent literature regarding administration of gadolinium in pregnant patients, and discusses technical requirements when imaging pregnant patients. A protocol for imaging pregnant patients is provided, and multiple common indications for MRI in pregnancy are discussed. Level of Evidence 5. Technical Efficacy Stage 5. J. Magn. Reson. Imaging 2019;49:621-631.

Accuracy of Diffusion-weighted Magnetic Resonance Imaging in Detecting Mucosal Healing and Treatment Response, and in Predicting Surgery, in Crohn's Disease

BACKGROUND AND AIMS

The Nancy score is a luminal Crohn's disease [CD] activity index applied in diffusion-weighted magnetic resonance imaging [DW-MRI]. We assessed the accuracy of the Nancy score in detecting mucosal healing and treatment response, and in predicting surgery.

METHODS

This was a retrospective, single-centre study of all patients with active CD and serial DW-MRI before and after treatment initiation with a biologic drug, between January 2010 and September 2016. The gold standard was endoscopy. The association between the Nancy score and the cumulative probability of intestinal resection during follow-up was tested combining Kaplan-Meier curves and log-rank testing.

RESULTS

A total of 96 patients were included; 20 had concomitantly undergone endoscopy. The Nancy score correlated well with the Crohn's Disease Endoscopic Index of Severity [r = 0.60 for the total score and r = 0.63 for the segmental score]. A total Nancy score <6 and a segmental Nancy score <2 detected mucosal healing with an area under the receiver operating characteristic curve [AUROC] of 0.82 (95% confidence interval [CI] 0.69-0.94, p <0.0001) and 0.80 [95% CI 0.73-0.87, p <0.0001], respectively. The Nancy score was highly sensitive to changes [Guyatt's responsiveness indices: 1.18 for the total score and 0.85 for the segmental score]. Mucosal healing on DW-MRI after treatment initiation was associated with a lower cumulative probability of intestinal surgery (p = 0.0251, median [interquartile range: IQR] follow-up 2.2 [1.6-3.7] years).

CONCLUSIONS

In CD, the Nancy score accurately detects mucosal healing and treatment response, the latter associated with a lower likelihood of intestinal resection.

Use of pre-operative imaging for symptomatic uterine myomas during pregnancy: a case report and a systematic literature review

PURPOSE

Uterine fibroids (UFs) occur in 10% of pregnancies and may lead to severe maternal-fetal complications, mainly depending on UFs characteristics and the distance to the uterine cavity (UC). When symptomatic, UFs are managed medically. Nevertheless, in about 2% of cases, surgery becomes necessary. Entry into the UC should be avoided during myomectomy. Consequentially, pre-operative assessment of this risk could be beneficial. Ultrasonography (US) represents the gold standard for UFs assessment; however, scarce evidence has been produced to assess the role of magnetic resonance imaging (MRI). The aim of the present study was to summarize current evidence about the pre-operative use of imaging techniques for UFs during pregnancy.

METHODS

A systematic research of the literature was conducted in Scopus, PubMed/MEDLINE, ScienceDirect and the Cochrane Library, including case reports and case series. A case report was also discussed. We collected data regarding patients, imaging assessment, UFs characteristics, surgical information, timing and modality of delivery.

RESULTS

According to our search strategy, 66 articles were selected and 210 patients were included. US assessment was reported in 36 (17%) cases. MRI was reported in 10 (4.7%) cases. Only in one case, MRI was used to measure the distance between UFs and UC.

CONCLUSION

US allows an adequate pre-operative evaluation of anterior, submucosal or pedunculated symptomatic UFs in pregnancy. However, compared to US, MRI may provide a more accurate evaluation of multiple, large, intramural or posterior UFs and could measure the distance between UFs and UC more accurately.

Imaging neurological emergencies in pregnancy and puerperium

The altered physiologic state of female patients during and just after pregnancy places them at an increased risk for several potentially life-threatening neurologic disorders. Swift diagnosis of such pathology and related complications is critical in order to reduce risk of morbidity and mortality to both the mother and the fetus. Neuroimaging plays an important role in the emergent diagnosis of pathology associated with pregnancy and puerperium, and it is critical for the radiologist to be cognizant of correlative imaging findings. Furthermore, given concerns regarding risks of neuroimaging to the fetus, it is important for the radiologist to act as an informed consultant regarding balancing fetal risks and the mother's health. The purpose of this review is to elucidate the underlying pathophysiology and neuroimaging findings associated with diagnoses that are unique to or highly associated with pregnancy and puerperium, as well as to understand the role that CT and MR play in diagnosis during and just after pregnancy, and their respective risks to the fetus.