Pregnancy-related chronic type A aortic dissection highlights the importance of thorough prenatal maternal examination

BACKGROUND

Aortic dissection occurs rarely during pregnancy but carries a significantly high vital risk for both the mother and the fetus. Early diagnosis and treatment are critical for a successful outcome.

CASE PRESENTATION

A 32-year-old pregnant woman at 31 weeks of gestation began experiencing shortness of breath, chest pain, and palpitations, which were attributed to an anxiety disorder she had been previously diagnosed with. The symptoms continued to worsen following the delivery when a chest computed tomography investigation revealed signs of chronic type A aortic dissection and an 80 mm post-dissection aneurysm of the ascending aorta. Aortic repair via composite aortic root replacement surgery (Bentall procedure) and partial aortic arch replacement was performed. The patient's postoperative evolution was notable for a series of complications.

CONCLUSIONS

Our report highlights the importance of thorough maternal examination during pregnancy. The high mortality rates associated with aortic dissection occurring in pregnant women and the possibility of missed intervention due to atypical clinical presentation warrant the need for standardized international protocols aimed at the prevention and timely diagnosis of prenatal aortic disease.

Improving Image Quality and Decreasing SAR With High Dielectric Constant Pads in 3 T Fetal MRI

BACKGROUND

At high magnetic fields, degraded image quality due to dielectric artifacts and elevated specific absorption rate (SAR) are two technical challenges in fetal MRI.

PURPOSE

To assess the potential of high dielectric constant (HDC) pad in increasing image quality and decreasing SAR for 3 T fetal MRI.

STUDY TYPE

Prospective.

FIELD STRENGTH/SEQUENCE

3 T. Balanced steady-state free precession (bSSFP) and single-shot fast spin-echo (SSFSE).

POPULATION

One hundred twenty-eight participants (maternal-age 29.0 ± 3.6, range 20-40; gestational-age 30.3 ± 3.5 weeks, range 22-37 weeks) undertook bSSFP and 40 participants (maternal-age 29.5 ± 3.8, range 19-40; gestational-age 30.4 ± 3.5 weeks, range 23-37 weeks) undertook SSFSE.

ASSESSMENT

Patient clinical characteristics were recorded, such as gestational-age, amniotic-fluid-index, abdominal-circumference, body-mass-index, and fetal-presentation. Quantitative Image-quality analysis included signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). Qualitative analysis was performed by three radiologists with four-point scale to evaluate overall image quality, dielectric artifact, and diagnostic confidence. Whole-body total SAR was obtained from the vendor workstation.

STATISTICAL TESTING

Paired rank sum test was used to analyze the differences in SNR, CNR, overall image quality, dielectric artifact, diagnostic confidence, and SAR with and without HDC pad. Spearman correlation test was used to detect correlations between image quality variable changes and patient clinical characteristics. P values <0.05 were set as statistical significance.

RESULTS

With HDC pad, SNR and CNR was significantly higher (41.45% increase in SNR, 54.05% increase in CNR on bSSFP; 258.76% increase in SNR, 459.55% increase in CNR on SSFSE). Overall qualitative image quality, dielectric artifact and diagnostic confidence improved significantly. Adding HDC pad significantly reduced Whole-body total SAR (32.60% on bSSFP; 15.40% on SSFSE). There was no significant correlation between image quality variable changes and participant clinical characteristics (P-values ranging from 0.072 to 0.992).

DATA CONCLUSION

In the clinical setting, adding a HDC pad might increase image quality while reducing dielectric artifact and SAR.

PLAN LANGUAGE SUMMARY

Dielectric artifacts and elevated SAR are two technical problems in 3T fetal MRI. In a prospective analysis of 168 pregnant participants undertaking 3.0T fetal MRI scanning, high dielectric constant (HDC) pad increased SNR by 41.45%, CNR by 54.05% on bSSFP, and SNR by 258.76%, CNR by 459.55% on SSFSE. Overall image quality, dielectric artifact reduction, and diagnostic confidence assessed by three radiologists was improved. Whole-body total SAR decreased by 32.60% on bSSFP and by 15.40% on SSFSE. These findings suggested that the HDC pad can enhance fetal MRI safety and quality, making it a promising tool for clinical practice.

EVIDENCE LEVEL

2 TECHNICAL EFFICACY: Stage 5.

Longitudinal investigation of neurobiological changes across pregnancy

Pregnancy is a period of profound biological transformation. However, we know remarkably little about pregnancy-related brain changes. To address this gap, we chart longitudinal changes in brain structure during pregnancy and explore potential mechanisms driving these changes. Ten participants (Mean age = 28.97 years) are assessed 1-6 times (median = 3) during their pregnancy. Each visit includes anatomical and diffusion-weighted MRI, and assessments of waking salivary hormones, hair hormones, and inflammatory cytokines. Here we observe a reduction in gray matter volume and an increase in neurite density index (NDI), a proxy of axon density, in white matter tracts across pregnancy. Progesterone levels are associated with reductions in brain volumetric measurements, and both progesterone and estradiol levels are linked to increases in NDI in white matter tracts. This study highlights the profound neurobiological changes experienced by pregnant individuals and provides insights into neuroplasticity in adulthood.

Fetal Safety in MRI During Pregnancy: A Comprehensive Review

As medical imaging continues to expand, concerns about the potential risks of ionizing radiation to the developing fetus have led to a preference for non-radiation-based alternatives such as ultrasonography and fetal MRI. This review examines the current evidence on the safety of MRI during pregnancy, with a focus on 3 T MRI and contrast agents, aiming to provide a comprehensive synthesis that informs clinical decision-making, ensures fetal safety and supports the safe use of all available modalities that could impact management. We conducted a comprehensive review of studies from 2000 to 2024 on MRI safety during pregnancy, focusing on 3 T MRI and gadolinium use. The review included peer-reviewed articles and large database studies, summarizing key findings and identifying areas for further research. Fetal MRI, used alongside ultrasound, enhances diagnostic accuracy for fetal anomalies, particularly in the brain, thorax, gastrointestinal and genitourinary systems, with no conclusive evidence of adverse effects on fetal development. While theoretical risks such as tissue heating and acoustic damage exist, studies show no significant harm at 1.5 T or 3 T, though caution is still advised in the first trimester. Regarding gadolinium-based contrast agents, the evidence is conflicting: while some studies suggest risks such as stillbirth and rheumatological conditions, animal studies show minimal fetal retention and no significant toxicity, and later clinical research has not substantiated these risks. The existing literature on fetal MRI is encouraging, suggesting minimal risks; however, further investigation through larger, prospective and long-term follow-up studies is essential to comprehensively determine its safety and late effects.

Longitudinal Investigation of Neurobiological Changes Across Pregnancy

Pregnancy is a period of profound biological transformation. However, we know remarkably little about pregnancy-related brain changes. To address this gap, we chart longitudinal changes in brain structure during pregnancy and explore potential mechanisms driving these changes. Ten participants (Mean age = 28.97 years) are assessed 1-6 times (median = 3) during their pregnancy. Each visit includes anatomical and diffusion-weighted MRI, and assessments of waking salivary hormones, hair hormones, and inflammatory cytokines. Here we observe a reduction in gray matter volume gestational week, while neurite density index (NDI), a proxy of axon density, in white matter tracts increase across pregnancy. Progesterone levels are associated with reductions in brain volumetric measurements, and both progesterone and estradiol levels are linked to increases in NDI in white matter tracts. This study highlights the profound neurobiological changes experienced by pregnant individuals and provides insights into neuroplasticity in adulthood.

Prenatal imaging - role of fetal MRI

Congenital abnormalities occur in about 3 in 100 fetuses. Prenatal ultrasound is the standard technique to detect these fetal abnormalities. In Germany, three ultrasound examinations are provided in the first, second, and third trimesters, respectively. Fetal magnetic resonance imaging (MRI) can be used as an adjunct technique to provide further information in cases of congenital abnormalities.A literature search was performed on PubMed focusing on publications that used fetal MRI as a secondary approach after prenatal ultrasound.MRI is a safe imaging method that does not harm the fetus when used during pregnancy. Some publications with experts in radiology show a very clear diagnostic advantage with respect to performing MRI on fetuses with brain abnormalities, while other publications with experts in neurosonography do not find the advantage to be that evident. Both techniques are clearly user-dependent.Fetal MRI can supplement the information obtained by fetal ultrasound and can provide additional information or exclude others. Diagnosis made by an interdisciplinary cooperation based on all available ultrasound and MRI findings is the key to optimal imaging and advice for expectant parents. · Fetal MRI poses no risk for the fetus.. · MRI aids prenatal ultrasound in the evaluation of prenatal findings.. · Tavares de Sousa M, Schönnagel BP, Denecke J et al. Prenatal imaging - role of fetal MRI. Fortschr Röntgenstr 2024; DOI 10.1055/a-2357-6997.

Breastfeeding in metabolic and bariatric patients: a comprehensive guide for surgeons, patients, and the multidisciplinary team

Since nearly 40% of metabolic and bariatric surgery (MBS) patients are individuals with the ability to bear children, many may seek to become pregnant or may be currently lactating when seeking surgery. While many patients plan to breastfeed, MBS patients are at high risk for premature cessation of breastfeeding. Limited literature exists on the impact of MBS on lactation and there are no established guidelines to help clinicians support and educate MBS patients about breastfeeding. Herein, we aim to fill that gap by providing a comprehensive guide for bariatric surgeons, obstetricians, women's health providers, lactation consultants, registered dietitians, bariatric nurse coordinators, and advanced practice providers to support breastfeeding in patients with a history of MBS or who are considering MBS. We review physician-patient discussion points on how MBS impacts lactation, the micronutrient and caloric needs for this unique population, and data to support successful breastfeeding in post-MBS patients who are lactating regarding practical, anesthetic, and imaging considerations.

Prenatal assessment of brain malformations on neuroimaging: an expert panel review

Brain malformations represent a heterogeneous group of abnormalities of neural morphogenesis, often associated with aberrations of neuronal connectivity and brain volume. Prenatal detection of brain malformations requires a clear understanding of embryology and developmental morphology through the various stages of gestation. This expert panel review is written with the central aim of providing an easy-to-understand road map to improve prenatal detection and characterization of structural malformations based on the current understanding of normal and aberrant brain development. For every developmental stage, the utility of each available neuroimaging modality, including prenatal multiplanar neuro sonography, anatomical MRI and advanced MRI techniques, as well as further insights from post-mortem imaging, has been highlighted.

Fetal body composition reference charts and sexual dimorphism using magnetic resonance imaging

BACKGROUND

The American Academy of Pediatrics advises that the nutrition of preterm infants should target a body composition similar to that of a fetus in utero. Still, reference charts for intrauterine body composition are missing. Moreover, data on sexual differences in intrauterine body composition during pregnancy are limited.

OBJECTIVES

The objective of this study was to create reference charts for intrauterine body composition from 30 to 36+6 weeks postconception and to evaluate the differences between sexes.

METHODS

In this single-center retrospective study, data from 197 normal developing fetuses in late gestation was acquired at 3T magnetic resonance imaging (MRI) scans, including True Fast Imaging with Steady State Free Precession and T1-weighted 2-point Dixon sequences covering the entire fetus. Deep convolutional neural networks were utilized to automatically segment the fetal body and subcutaneous adipose tissue. The fetus's body mass (BM), fat signal fraction (FSF), fat mass (FM), FM percentage (FM%), fat-free mass (FFM), and FFM percentage (FFM%) were calculated. Using the Generalized Additive Models for Location, Scale, and Shape (GAMLSS) method, reference charts were created, and sexual dimorphism was examined using analysis of covariance (ANCOVA). A P value <0.05 was deemed significant.

RESULTS

Throughout late gestation, BM, FSF, FM, FM%, and FFM increased, while the FFM% decreased. Reference charts for gestational age and sex-specific percentiles are provided. Males exhibited significantly higher BM (7.2%; 95% confidence interval [95% CI]: 1.9, 12.4), FFM (8.8%; 95% CI: 5.8, 11.9), and FFM% (1.7%; 95% CI: 1, 2.4) and lower FSF (-3.6%; 95% CI: -5.6, -1.8) and FM% (-1.7%; 95% CI: -2.4, -1), (P < 0.001) compared with females, with no significant difference in FM between sexes (P = 0.876).

CONCLUSIONS

MRI-derived intrauterine body composition growth charts are valuable for tracking growth in preterm infants. This study demonstrated that sexual differences in body composition are already present in the intrauterine phase.

Neonatal Anthropometric Measurements: A Comparison of Neonates With 3-T Fetal MRI Exposure, With 1.5-T Fetal MRI Exposure, and Without In-Utero MRI Exposure

BACKGROUND. Fetal MRI is increasingly performed at 3 T. Nonetheless, safety concerns persist regarding potential increased risk of intrauterine growth restriction from in-utero 3-T MRI exposure. OBJECTIVE. The purpose of this study was to compare neonatal anthropometric measurements between neonates who underwent 3-T fetal MRI, neonates who underwent 1.5-T fetal MRI, and neonates without in-utero MRI exposure. METHODS. This single-center retrospective study included gravid patients who underwent fetal ultrasound and possible 1.5-T or 3-T fetal MRI within 10 days between January 2017 and January 2022. For each included patient who also underwent 3-T fetal MRI, one matched patient who also underwent 1.5-T MRI and two matched patients without in-utero MRI exposure were randomly selected. Matching was based on gestational age at the time of the fetal ultrasound. Neonatal anthropometric characteristics were compared among groups. RESULTS. The final sample included 416 patients (mean age, 32 ± 5 [SD] years), 104 in the 3-T MRI group, 104 in the 1.5-T MRI group, and 208 in the MRI-unexposed group. The mean gestational age at the time of fetal ultrasound used for matching was 27 weeks 2 days in the 3-T group, 25 weeks 2 days in the 1.5-T group, and 26 weeks 0 days in the MRI-unexposed group (p = .07). The distribution of indications for fetal MRI was not significantly different between the 3-T and 1.5-T groups (p = .56). The mean gestational age at delivery was 37 weeks 5 days in the 3-T group, 38 weeks 0 days in the 1.5-T group, and 38 weeks 2 days in the unexposed group (p = .51). No significant difference was observed among the groups in mean neonatal weight (3 T: 3120 ± 753 [SD] g; 1.5 T: 3104 ± 704 g; unexposed: 2967 ± 614 g; p = .09), mean neonatal weight percentile (3 T: 45 ± 27 [SD]; 1.5 T: 42 ± 26; unexposed: 41 ± 24; p = .56), mean neonatal head circumference (3 T: 34 ± 3 [SD] cm; 1.5 T: 34 ± 3 cm; unexposed: 34 ± 2 cm; p = .05), or mean neonatal head circumference percentile (3 T: 48 ± 29 [SD]; 1.5 T: 42 ± 23; unexposed: 43 ± 30; p = .32). CONCLUSION. There were no significant differences in neonatal anthropometric measurements among neonates who underwent in-utero 3-T MRI, neonates who underwent in-utero 1.5-T MRI, and neonates without in-utero MRI exposure. CLINICAL IMPACT. The results support the safety of 3-T MRI with respect to the growth of the developing fetus.

Relative Mediastinal Displacement Index (RMDI): A Prenatal MRI Indicator of Adverse Events in Fetuses With Isolated Left Congenital Diaphragmatic Hernia

BACKGROUND

Extracorporeal membrane oxygenation (ECMO), has partly improved congenital diaphragmatic hernia (CDH) outcomes, yet the overall morbidity and mortality remain high. Existing prenatal indicators for CDH fetuses are operator-dependent, time-consuming, or less accurate, a new simple and accurate indicator to indicate adverse events in CDH patients is needed.

PURPOSE

To propose and assess the association of a new MRI parameter, the relative mediastinal displacement index (RMDI), with adverse events including in-hospital deaths or the need for ECMO in fetuses with isolated left CDH (iLCDH).

STUDY TYPE

Retrospective analysis.

SUBJECTS

One hundred thirty-nine fetuses were included in the iLCDH group (24 with adverse events and 115 without) and 257 fetuses were included in the control group from two centers in Guangzhou.

FIELD STRENGTH/SEQUENCE

3.0 T, T2WI-TRUFI; 1.5 T, T2WI-FIESTA.

ASSESSMENT

Three operators independently measured the→ DL ,→ DR , and DH on the axial images. The calculation formula of the RMDI was (→ DL  + → DR )/DH.

STATISTICAL TESTS

The independent sample t test, Mann-Whitney U test, Chi-square test, Chi-square test continuity correction, Fisher's test, linear regression analysis, logistic regression analysis, intraclass correlation coefficient, receiver operating characteristic curve analysis, and Delong test. A P value <0.05 was considered statistically significant.

RESULTS

The RMDI did not change with gestational age in the iLCDH group (with [P = 0.189] and without [P = 0.567] adverse events) and the control group (P = 0.876). There were significant differences in RMDI between the iLCDH group (0.89 [0.65, 1.00]) and the control group (-0.23 [-0.34, -0.16]). In the iLCDH group, RMDI was the only indicator left for indicating adverse events, and the best cutoff value was 1.105. Moreover, there was a significant difference in diagnostic accuracy between the RMDI (AUC = 0.900) and MSA (AUC = 0.820), LHR (AUC = 0.753), o/e LHR (AUC = 0.709), and o/e TFLV (AUC = 0.728), respectively.

DATA CONCLUSION

The RMDI is expected to be a simple and accurate tool for indicating adverse events in fetuses with iLCDH.

EVIDENCE LEVEL

4 TECHNICAL EFFICACY: Stage 1.

Emergency lumbar disc herniation surgery with spinal anesthesia during pregnancy: Clinical features and long-term outcome

BACKGROUND

This study aimed to review the safety and prognosis of emergency lumbar microdiscectomy surgery during pregnancy.

METHODS

The study included a cohort of ten consecutive pregnant patients who underwent urgent lumbar microdiscectomy surgery between 2016 and 2022-perioperative and perinatal clinical data derived from medical records-a retrospective analysis. The patients were evaluated based on age, gestational age, gravidity, parity, neurological examination findings, and visual analog scale (VAS) pain scores with the early and late postoperative results of mother and newborns with follow-up.

RESULTS

Ten pregnant patients underwent emergency lumbar microdiscectomy surgery during pregnancy. Median maternal age was 29.8 ± 4.02 years (range, 21-34 years), and the mean gestational age was 18.2 ± 5.43 weeks (range, 9-26 weeks). Indications were lumbar disk prolapse (n = 10, including cauda equina, motor deficits with severe pain). All surgeries were performed with the patients in the prone position under spinal anesthesia. No miscarriages, stillbirths, or severe obstetric complications occurred until delivery. All patients improved neurologically after the surgery and, were mobile and could take care of their infants. All 10 infants who were healthy at birth had an unremarkable postnatal development, without any congenital defect.

CONCLUSIONS

Urgent lumbar microdiscectomy during pregnancy seems to be safe and maintenance of pregnancy is possible and feasible.

[Research Progress in Magnetic Resonance Imaging of Fetal Ventriculomegaly]

Fetal ventriculomegaly is a central nervous system disorder commonly seen in prenatal imaging, and the prognosis ranges from normal health to severe dysfunction. Currently, fetal predictive markers associated with postpartum individual neurodevelopmental function are still not available, which increases the difficulty of prenatal diagnosis and clinical management. Constant advancements in magnetic resonance imaging (MRI) technology have brought better accuracy and reliability of MRI applied in the diagnosis, prognosis assessment, and etiology investigation of ventriculomegaly. MRI plays a critical role in prognostic management and prenatal consultation. Nevertheless, due to the potential safety hazards and economic and technical constraints of MRI, it is not the first choice for prenatal imaging diagnosis. Moreover, there are different opinions regarding the measurement results and grading criteria of ultrasound and MRI. At present, it is accepted that three-dimensional volume may provide reliable information for prognosis. However, accurate segmentation and measurement of brain structure remain serious challenges, and no consensus on the MRI measurement of lateral ventricle volume has been reached. In this paper, based on the latest research reports from China and around the world, we reviewed the progress in applying MRI in the prenatal diagnosis and treatment of ventriculomegaly. This review offers a theoretical foundation for further exploration of the role of lateral ventricle volume measurement in disease diagnosis and management. We suggest that researchers combine two-dimensional width with three-dimensional volume in the future to identify the optimal cutoff value for prognostic prediction of fetal ventriculomegaly.

Pearls and Pitfalls of Imaging Small Bowel Obstruction

Small bowel obstruction (SBO) is a common condition encountered by radiologists in the evaluation of patients with abdominal pain, and is an important diagnosis to be comfortable with given substantial associated morbidity and mortality. In this review, we summarize an imaging approach to evaluating patients with suspected SBO, discuss the role of certain imaging modalities such as radiography and small bowel follow through, CT, and MRI, as well as review some common and also less common causes of SBO such as internal hernia. We will also discuss tailoring the imaging approach to address specific clinical questions and special patient populations such as imaging the pregnant patient with suspected SBO, and the inflammatory bowel disease patient.

3 Tesla Fetal MR Imaging Quality and Safety Considerations

Medical imaging, particularly fetal MR imaging, has undergone a transformative shift with the introduction of 3 Tesla (3T) clinical MR imaging systems. The utilization of higher static magnetic fields in these systems has resulted in remarkable advancements, including superior soft tissue contrast, improved spatial and temporal resolution, and reduced image acquisition time. Despite these notable benefits, safety concerns have emerged, stemming from the elevated static magnetic field strength, amplified acoustic noise, and increased radiofrequency power deposition. This article provides an overview of fetal MR imaging at 3T, its benefits and drawbacks, and the potential safety issues.

How to Perform Fetal MR Imaging

This article provides the readers with practical guidance on how to perform fetal MR imaging, including technical considerations such as scanner field strength and use of appropriate radiofrequency receive coils, and summarizes the role, strengths, and limitations of the various MR imaging sequences. The authors review the various factors to consider in scan preparation, including study indication, timing, maternal preparation, and the creation of an institutional fetal imaging protocol. Additional factors that go into scan optimization during acquisition including prioritizing maternal comfort and ways to troubleshoot various artifacts that maybe encountered in fetal imaging are discussed.

Fetal Cardiac MRI Using Doppler US Gating: Emerging Technology and Clinical Implications

Fetal cardiac MRI using Doppler US gating is an emerging technique to support prenatal diagnosis of congenital heart disease and other cardiovascular abnormalities. Analogous to postnatal electrocardiographically gated cardiac MRI, this technique enables directly gated MRI of the fetal heart throughout the cardiac cycle, allowing for immediate data reconstruction and review of image quality. This review outlines the technical principles and challenges of cardiac MRI with Doppler US gating, such as loss of gating signal due to fetal movement. A practical workflow of patient preparation for the use of Doppler US-gated fetal cardiac MRI in clinical routine is provided. Currently applied MRI sequences (ie, cine or four-dimensional flow imaging), with special consideration of technical adaptations to the fetal heart, are summarized. The authors provide a literature review on the clinical benefits of Doppler US-gated fetal cardiac MRI for gaining additional diagnostic information on cardiovascular malformations and fetal hemodynamics. Finally, future perspectives of Doppler US-gated fetal cardiac MRI and further technical developments to reduce acquisition times and eliminate sources of artifacts are discussed. Keywords: MR Fetal, Ultrasound Doppler, Cardiac, Heart, Congenital, Obstetrics, Fetus Supplemental material is available for this article. © RSNA, 2024.

The Impact of Pregnancy in Patients with Thoracic Aortic Disease: Epidemiology, Risk Assessment, and Management Considerations

Thoracic aortic disease (TAD) poses substantial risks during pregnancy, particularly for women with genetic conditions such as Marfan syndrome, Loeys-Dietz syndrome, and vascular Ehlers-Danlos syndrome. This review examines the epidemiology, risk assessment, and management of TAD in pregnancy. Preconception counseling is vital considering the hereditary nature of TAD and potential pregnancy-related complications. Genetic testing and imaging surveillance aid in risk assessment. Medical management, including beta-blockade and strict blood pressure control, is essential throughout pregnancy. Surgical interventions may be necessary in certain cases. A multidisciplinary approach involving cardiologists, obstetricians, cardiac surgeons, anesthesiologists, and other specialists with expertise in cardio-obstetrics is essential for optimal outcomes. Patient education and shared decision-making play vital roles in navigating the complexities of TAD in pregnancy and improving maternal and neonatal outcomes.

Survey of maternal anxiety and perceptions towards foetal MRI and pre-scan education

INTRODUCTION

Foetal MRI scans can induce feelings of fear, concern and anxiety in pregnant patients. The aim of this research was to determine if providing patients with an information leaflet reduced maternal anxiety regarding foetal MRI.

METHODS

A prospective, three-arm comparative pilot study was performed in the MRI department of a quaternary public hospital in Brisbane, Australia. Three groups of 30 participants (total 90 participants) received differing levels of information about foetal MRI: Group A - no foetal-MRI specific information (current practice at the site); Group B - a basic information leaflet; Group C - a comprehensive information leaflet. All participants completed a survey that explored their pre-scan anxiety immediately after their MRI scan.

RESULTS

Over 50% of participants in each group felt anxious before the MRI. Participants expressed anxiety towards the general process of the MRI, the outcome or results of the scan, and the safety of the modality. The basic and comprehensive leaflets were both efficacious in reducing anxiety for the majority of participants.

CONCLUSIONS

Whilst not all patients express anxiety regarding MRI scans, emotional distress surrounding the entire process is prevalent. Providing patients with comprehensive information about what the MRI scan entails (including the scan environment and duration, positioning, breath-holding requirements, and foetal safety) reduces anxiety for most patients. These findings can be used to determine ways in which reduction of anxiety improves the patient experience.

Medical Imaging in Pregnancy: Safety, Appropriate Utilization, and Alternative Modalities for Imaging Pregnant Patients

This article reviews the existing literature on diagnostic and medical imaging of pregnant women, the risks and safety measures of different medical imaging modalities, and alternative modalities for imaging pregnant patients. Different medical imaging modalities such as MRI, CT scan, ultrasound, nuclear medicine, and X-ray imaging help to evaluate women with recognized or unrecognized pregnancies and identify any underlying complications among pregnant patients. Fetuses are more sensitive to radiation and the effects of medical imaging as compared to adults since they have a rapidly developing cell system. During cell proliferation, migration, and differentiation, fetuses suffer greatly from imaging radiation since they are developing under a dynamic system. To ensure safety, pregnant women should discuss the benefits and risks of medical imaging with their physicians. In addition, radiologists should not perform any medical imaging procedure without the patient's consent, unless the patient cannot make any sound decision. Fetal risks of medical imaging include slow growth and development of the fetus, abortion, malformations, impaired brain function, abnormal childhood growth, and neurological development. Diagnostic imaging procedures are necessary when a condition that needs medical evaluation arises during pregnancy such as appendicitis.

2022 ACC/AHA guideline for the diagnosis and management of aortic disease: A report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines

AIM

The "2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease" provides recommendations to guide clinicians in the diagnosis, genetic evaluation and family screening, medical therapy, endovascular and surgical treatment, and long-term surveillance of patients with aortic disease across its multiple clinical presentation subsets (ie, asymptomatic, stable symptomatic, and acute aortic syndromes).

METHODS

A comprehensive literature search was conducted from January 2021 to April 2021, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through June 2022 during the guideline writing process, were also considered by the writing committee, where appropriate.

STRUCTURE

Recommendations from previously published AHA/ACC guidelines on thoracic aortic disease, peripheral artery disease, and bicuspid aortic valve disease have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with aortic disease have been developed. There is added emphasis on the role of shared decision making, especially in the management of patients with aortic disease both before and during pregnancy. The is also an increased emphasis on the importance of institutional interventional volume and multidisciplinary aortic team expertise in the care of patients with aortic disease.

Safety of Magnetic Resonance Imaging in Pregnancy

Magnetic resonance imaging is being increasingly used to diagnose and follow up a variety of medical conditions in pregnancy, both for maternal and fetal indications. However, limited data regarding its safe use in pregnancy may be a source of anxiety and avoidance for both patients and their healthcare providers. In this review, we critically discuss the main safety concerns of Magnetic Resonance Imaging (MRI) in pregnancy including energy deposition, acoustic noise, and use of contrast agents, supported by data from animal and human studies. Use of maternal sedatives and concerns related to occupational exposure in pregnant personnel are also addressed. Exposure to gadolinium-based contrast agents and sedation for MRI during pregnancy should be avoided whenever feasible.

Effect of magnet strength on fetal brain biometry - a single-center retrospective MRI-based cohort study

PURPOSE

Abnormal fetal brain measurements might affect clinical management and parental counseling. The effect of between-field-strength differences was not evaluated in quantitative fetal brain imaging until now. Our study aimed to compare fetal brain biometry measurements in 3.0 T with 1.5 T scanners.

METHODS

A retrospective cohort of 1150 low-risk fetuses scanned between 2012 and 2021, with apparently normal brain anatomy, were retrospectively evaluated for biometric measurements. The cohort included 1.5 T (442 fetuses) and 3.0 T scans (708 fetuses) of populations with comparable characteristics in the same tertiary medical center. Manually measured biometry included bi-parietal, fronto-occipital and trans-cerebellar diameters, length of the corpus-callosum, vermis height, and width. Measurements were then converted to centiles based on previously reported biometric reference charts. The 1.5 T centiles were compared with the 3.0 T centiles.

RESULTS

No significant differences between centiles of bi-parietal diameter, trans-cerebellar diameter, or length of the corpus callosum between 1.5 T and 3.0 T scanners were found. Small absolute differences were found in the vermis height, with higher centiles in the 3.0 T, compared to the 1.5 T scanner (54.6th-centile, vs. 39.0th-centile, p < 0.001); less significant differences were found in vermis width centiles (46.9th-centile vs. 37.5th-centile, p = 0.03). Fronto-occipital diameter was higher in 1.5 T than in the 3.0 T scanner (66.0th-centile vs. 61.8th-centile, p = 0.02).

CONCLUSIONS

The increasing use of 3.0 T MRI for fetal imaging poses a potential bias when using 1.5 T-based charts. We elucidate those biometric measurements are comparable, with relatively small between-field-strength differences, when using manual biometric measurements. Small inter-magnet differences can be related to higher spatial resolution with 3 T scanners and may be substantial when evaluating small brain structures, such as the vermis.

Highlights and Perioperative Implications from the 2022 American College of Cardiology and American Heart Association Guidelines for Diagnosis and Management of Aortic Disease

As the understanding of aortic diseases and their complications grow, increasing importance of uniformity in diagnosis and management is crucial for optimal care of this patient population. The 2022 American College of Cardiology and American Heart Association Guidelines for Diagnosis and Management of Aortic Disease discusses these considerations in detail. The purpose of this review is to highlight essential recommendations that are of relevance to the perioperative physician who manages these patients. A few notable points include, shared decision-making with patients, creation of multidisciplinary aortic teams, lower diameter thresholds for surgery in certain situations, and increased testing for patients with heritable aortic diseases. In addition to briefly reviewing basics of aortic diseases, the authors discuss changes to guidelines that are especially relevant to perioperative care.

Patient safety in magnetic resonance imaging

Image acquisition involves the use of static magnetic fields, field gradients and radiofrequency waves. These elements make the MRI a different modality. More and more centers work with 3.0 T equipment that present higher risks for the patient, compared to those of 1.5 T. Therefore, there is a need for updating for radiology staff that allows them to understand the risks and reduce them, since serious and even fatal incidents can occur. The objective of this work is to present a review and update of the risks to which patients are subjected during the performance of a magnetic resonance imaging (MRI) study.

Fetal MRI: what's new? A short review

Fetal magnetic resonance imaging (fetal MRI) is usually performed as a second-level examination following routine ultrasound examination, generally exploiting morphological and diffusion MRI sequences. The objective of this review is to describe the novelties and new applications of fetal MRI, focusing on three main aspects: the new sequences with their applications, the transition from 1.5-T to 3-T magnetic field, and the new applications of artificial intelligence software. This review was carried out by consulting the MEDLINE references (PubMed) and including only peer-reviewed articles written in English. Among the most important novelties in fetal MRI, we find the intravoxel incoherent motion model which allow to discriminate the diffusion from the perfusion component in fetal and placenta tissues. The transition from 1.5-T to 3-T magnetic field allowed for higher quality images, thanks to the higher signal-to-noise ratio with a trade-off of more frequent artifacts. The application of motion-correction software makes it possible to overcome movement artifacts by obtaining higher quality images and to generate three-dimensional images useful in preoperative planning.Relevance statementThis review shows the latest developments offered by fetal MRI focusing on new sequences, transition from 1.5-T to 3-T magnetic field and the emerging role of AI software that are paving the way for new diagnostic strategies.Key points• Fetal magnetic resonance imaging (MRI) is a second-line imaging after ultrasound.• Diffusion-weighted imaging and intravoxel incoherent motion sequences provide quantitative biomarkers on fetal microstructure and perfusion.• 3-T MRI improves the detection of cerebral malformations.• 3-T MRI is useful for both body and nervous system indications.• Automatic MRI motion tracking overcomes fetal movement artifacts and improve fetal imaging.

The current state and potential innovation of fetal cardiac MRI

Fetal cardiac MRI is a rapidly evolving form of diagnostic testing with utility as a complementary imaging modality for the diagnosis of congenital heart disease and assessment of the fetal cardiovascular system. Previous technical limitations without cardiac gating for the fetal heart rate has been overcome with recent technology. There is potential utility of fetal electrocardiography for direct cardiac gating. In addition to anatomic assessment, innovative technology has allowed for assessment of blood flow, 3D datasets, and 4D flow, providing important insight into fetal cardiovascular physiology. Despite remaining technical barriers, with increased use of fCMR worldwide, it will become an important clinical tool to improve the prenatal care of fetuses with CHD.

Fetal lung MRI and features predicting post-natal outcome: a scoping review of the current literature

The outcome for infants with fetal lung pathologies not only depends on the nature of the pathology, but the impact it has on the developing lungs. The main prognostic factor is the degree of pulmonary hypoplasia, but this is not detectable pre-natally. Imaging techniques aim to simulate these features with a variety of surrogate measurements, including lung volume and MRI signal intensity. Despite the complexity of the various research studies and lack of consistent methodology, this scoping review aims to summarise current applications, and promising techniques requiring further investigation.

No Meta-analytic Evidence for Risks due to Prenatal Magnetic Resonance Imaging in Animal Models

BACKGROUND

Magnetic resonance imaging (MRI) is a powerful, noninvasive tool for both clinical practice and research. Though the safety of MRI has been endorsed by many professional societies and government bodies, some concerns have remained about potential risk from prenatal MRI. Case-control animal studies of MRI scanning during gestation and effects on offspring are the most direct test available for potential risks. We performed a meta-analysis of extant animal studies of prenatal MRI examining reproductive and offspring outcomes.

METHODS

Relevant articles were identified through PubMed search and citation searching of known articles and review papers. Eighteen relevant studies were identified with case-control designs of prenatal scanning conducted in vivo with mammalian species using MRI-relevant field strength. Standardized mean difference effect sizes were analyzed across k = 81 outcomes assessed across 649 unexposed dams, 622 exposed dams, 3024 unexposed offspring, and 3328 exposed offspring using a multilevel meta-analytic approach that clustered effect sizes within publications.

RESULTS

The meta-analysis indicated no significant evidence for a deleterious effects of prenatal MRI (standardized mean difference = 0.17, 95% CI [-0.19, 0.54], t80 = 0.94, p = .35) across outcomes. Similarly, no effects were observed when separately examining the 4 most commonly assessed outcomes: birth weight, litter size, fetal viability, and physical malformations (p > .05).

CONCLUSIONS

Case-control mammalian animal studies indicate no significant known risks of prenatal MRI to reproductive outcomes or offspring development. This finding is largely mirrored in human research, though the lack of randomized case-control designs limits direct comparison. The current findings provide additional support to the prevailing consensus that prenatal MRI poses no known risk to offspring.

Medicolegal considerations associated with cancer during pregnancy

The management of pregnant patients with cancer is complex and requires a multidisciplinary team to effectively diagnose, stage, and manage the cancer while also being cognizant of the potential harm that diagnosis and treatment may have on the maternal and fetal well-being. Beyond the complex clinical management of these patients is additional medicolegal consideration. Radiologists play a crucial role in the management of these patients as their knowledge of diagnostic and interventional radiology techniques allows for appropriate and safe imaging for both the mother and fetus. In addition, radiologist are able to educate patient on the different imaging modalities and techniques, thus allowing patients to make informed decisions and maintain autonomy over there care. This article will review safety considerations associated with different imaging modalities, contrast agents, interventional radiology procedures and moderate sedation related to the imaging of pregnant patient with cancer with specific attention paid to the medicolegal aspects.

Septic shock in obstetrics: guidelines of the All-Russian public organization “Federation of Anesthesiologists and Reanimatologists”

The article reflects the main provisions of the clinical guidelines on septic shock in obstetrics, approved by the All-Russian public organization “Federation of Anesthesiologists-Resuscitators” in 2022. The relevance of the problem is associated with high mortality and morbidity rates from sepsis and septic shock in obstetrics. The main issues of etiology, pathogenesis, clinical picture, methods of laboratory and instrumental diagnostics, features of using the qSOFA, SOFA, MOEWS, SOS, MEWC, IMEWS scales for sepsis verification are consistently presented. The article presents the starting intensive therapy (the first 6–12 hours) of the treatment of septic shock in obstetrics, taking into account the characteristics of the pregnant woman's body. The strategy of prescribing vasopressors (norepinephrine, phenylephrine, epinephrine), inotropic drugs (dobutamine) is described, antibiotics and optimal antibiotic therapy regimens, features of infusion and adjuvant therapy are presented. The issues of surgical treatment of the focus of infection and indications for hysterectomy, as well as the organization of medical care and rehabilitation of patients with sepsis and septic shock were discussed. The basic principles of prevention of sepsis and septic shock in obstetrics are described. The criteria for the quality of medical care for patients with septic shock and the algorithms of doctor's actions in the diagnosis and intensive care of patients with septic shock in obstetrics are presented.

Fetal MRI at 3 T: Principles to Optimize Success

Fetal MRI has emerged as a cornerstone of prenatal imaging, helping to establish the correct diagnosis in pregnancies affected by congenital anomalies. In the past decade, 3 T imaging was introduced as an alternative to increase the signal-to-noise ratio (SNR) of the pulse sequences and improve anatomic detail. However, imaging at a higher field strength is not without challenges. Many artifacts that are barely appreciable at 1.5 T are amplified at 3 T. A systematic approach to imaging at 3 T that incorporates appropriate patient positioning, a thoughtful protocol design, and sequence optimization minimizes the impact of these artifacts and allows radiologists to reap the benefits of the increased SNR. The sequences used are the same at both field strengths and include single-shot T2-weighted, balanced steady-state free-precession, three-dimensional T1-weighted spoiled gradient-echo, and echo-planar imaging. Synergistic use of these acquisitions to sample various tissue contrasts and in various planes provides valuable information about fetal anatomy and pathologic conditions. In the authors' experience, fetal imaging at 3 T outperforms imaging at 1.5 T for most indications when performed under optimal circumstances. The authors condense the cumulative experience of fetal imaging specialists and MRI technologists who practice at a large referral center into a guideline covering all major aspects of fetal MRI at 3 T, from patient preparation to image interpretation. © RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Effects of 1.5-T versus 3-T magnetic resonance imaging in fetuses: is there a difference in postnatal neurodevelopmental outcome? Evaluation in a fetal population with left-sided congenital diaphragmatic hernia

BACKGROUND

The utilization of 3-T magnetic field strength in obstetric imaging is increasingly common. It is important to ensure that magnetic resonance (MR) imaging with higher magnetic field strength is safe for the fetus. Comparison of neurodevelopmental outcome in neonates undergoing prenatal MR imaging with 1.5-T versus 3-T is of interest but has not yet been examined.

OBJECTIVE

We hypothesized no clinically meaningful difference in neurodevelopmental outcome between fetuses undergoing 1.5-T versus 3-T fetal MR imaging. As imaging a normal fetus for research purposes is illegal in Pennsylvania, this study was conducted in a population of fetuses with left congenital diaphragmatic hernia (left-CDH).

MATERIALS AND METHODS

A retrospective review of neurodevelopmental outcome of fetuses with left-CDH scanned at 1.5-T (n=75) versus 3-T (n=25) magnetic field strength between July of 2012 and December of 2019 was performed. Neurodevelopmental outcomes were assessed using the Bayley Scales of Infant Development, 3rd Edition (BSID-III).

RESULTS

There were no statistical differences in median age of assessment (1.5-T: 18 [12, 25] versus 3-T: 21 [11, 26], P=0.79), in mean BSID-III cognitive (1.5-T: 91 ± 14 versus 3-T: 90 ± 16, P=0.82), language (1.5-T: 92 ± 20 versus 3-T: 91 ± 20, P=0.91), and motor composite (1.5-T: 89 ± 15 versus 3-T: 87 ± 18, P=0.59) scores, subscales scores (for all, P>0.50), or in risk of abnormal neuromuscular exam (P=0.29) between neonates with left-CDH undergoing a 1.5-T versus 3-T MR imaging during fetal life. Additionally, the distribution of patients with average, mildly delayed, and severely delayed BSID-III scores was similar between the two groups (for all, P>0.50). The overall distribution of the composite scores in this CDH population was similar to the general population independent of exposure to 1.5-T or 3-T fetal MR imaging. Two 3-T patients (8%) and five 1.5-T patients (7%) scored within the significant delayed range for all BSID-III domains. Subjects with lower observed-to-expected fetal lung volume (O/E FLV) and postnatal need for ECMO had lower cognitive, language, motor, and subscales scores (for all, P<0.03) regardless of being imaged at 1.5-T versus 3-T.

CONCLUSION

This preliminary study suggests that, compared to 1.5-T MR imaging, fetal exposure to 3-T MR imaging does not increase the risk of neurodevelopmental impairment in fetuses with left-CDH. Additional MR imaging studies in larger CDH cohorts and other fetal populations are needed to replicate and extend the present findings.

Imaging of benign gallbladder and biliary pathologies in pregnancy

The rising incidence combined with pregnancy-related physiological changes make gallbladder and biliary pathology high on the differential for pregnant patients presenting with right upper abdominal pain. Imaging plays a crucial role in determining surgical versus non-surgical management in pregnant patients with biliary or gallbladder pathology. Ultrasound (first-line) and magnetic resonance with magnetic resonance cholangiopancreatography (second-line) are the imaging techniques of choice in pregnant patients with suspected biliary pathology due to their lack of ionizing radiation. MRI/MRCP offers an excellent non-invasive imaging option, providing detailed anatomical detail without known harmful fetal side effects. This article reviews physiological changes in pregnancy that lead to gallstone and biliary pathology, key imaging findings on US and MRI/MRCP, and management pathways.

Safety Considerations in MRI and CT

OBJECTIVE

MRI and CT are indispensable imaging modalities for the evaluation of patients with neurologic disease, and each is particularly well suited to address specific clinical questions. Although both of these imaging modalities have excellent safety profiles in clinical use as a result of concerted and dedicated efforts, each has potential physical and procedural risks that the practitioner should be aware of, which are described in this article.

LATEST DEVELOPMENTS

Recent advancements have been made in understanding and reducing safety risks with MR and CT. The magnetic fields in MRI create risks for dangerous projectile accidents, radiofrequency burns, and deleterious interactions with implanted devices, and serious patient injuries and deaths have occurred. Ionizing radiation in CT may be associated with shorter-term deterministic effects on biological tissues at extremely high doses and longer-term stochastic effects related to mutagenesis and carcinogenesis at low doses. The cancer risk of radiation exposure in diagnostic CT is considered extremely low, and the benefit of an appropriately indicated CT examination far outweighs the potential risk. Continuing major efforts are centered on improving image quality and the diagnostic power of CT while concurrently keeping radiation doses as low as reasonably achievable.

ESSENTIAL POINTS

An understanding of these MRI and CT safety issues that are central to contemporary radiology practice is essential for the safe and effective treatment of patients with neurologic disease.

European recommendations on practices in pediatric neuroradiology: consensus document from the European Society of Neuroradiology (ESNR), European Society of Paediatric Radiology (ESPR) and European Union of Medical Specialists Division of Neuroradiology (UEMS)

Pediatric neuroradiology is a subspecialty within radiology, with possible pathways to train within the discipline from neuroradiology or pediatric radiology. Formalized pediatric neuroradiology training programs are not available in most European countries. We aimed to construct a European consensus document providing recommendations for the safe practice of pediatric neuroradiology. We particularly emphasize imaging techniques that should be available, optimal site conditions and facilities, recommended team requirements and specific indications and protocol modifications for each imaging modality employed for pediatric neuroradiology studies. The present document serves as guidance to the optimal setup and organization for carrying out pediatric neuroradiology diagnostic and interventional procedures. Clinical activities should always be carried out in full agreement with national provisions and regulations. Continued education of all parties involved is a requisite for preserving pediatric neuroradiology practice at a high level.

2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease: A Report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines

AIM

The "2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease" provides recommendations to guide clinicians in the diagnosis, genetic evaluation and family screening, medical therapy, endovascular and surgical treatment, and long-term surveillance of patients with aortic disease across its multiple clinical presentation subsets (ie, asymptomatic, stable symptomatic, and acute aortic syndromes).

METHODS

A comprehensive literature search was conducted from January 2021 to April 2021, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through June 2022 during the guideline writing process, were also considered by the writing committee, where appropriate. Structure: Recommendations from previously published AHA/ACC guidelines on thoracic aortic disease, peripheral artery disease, and bicuspid aortic valve disease have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with aortic disease have been developed. There is added emphasis on the role of shared decision making, especially in the management of patients with aortic disease both before and during pregnancy. The is also an increased emphasis on the importance of institutional interventional volume and multidisciplinary aortic team expertise in the care of patients with aortic disease.

2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease: A Report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines

AIM

The "2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease" provides recommendations to guide clinicians in the diagnosis, genetic evaluation and family screening, medical therapy, endovascular and surgical treatment, and long-term surveillance of patients with aortic disease across its multiple clinical presentation subsets (ie, asymptomatic, stable symptomatic, and acute aortic syndromes).

METHODS

A comprehensive literature search was conducted from January 2021 to April 2021, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through June 2022 during the guideline writing process, were also considered by the writing committee, where appropriate.

STRUCTURE

Recommendations from previously published AHA/ACC guidelines on thoracic aortic disease, peripheral artery disease, and bicuspid aortic valve disease have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with aortic disease have been developed. There is added emphasis on the role of shared decision making, especially in the management of patients with aortic disease both before and during pregnancy. The is also an increased emphasis on the importance of institutional interventional volume and multidisciplinary aortic team expertise in the care of patients with aortic disease.

Imaging fetal anatomy

Due to advancements in ultrasound techniques, the focus of antenatal ultrasound screening is moving towards the first trimester of pregnancy. The early first trimester however remains in part, a 'black box', due to the size of the developing embryo and the limitations of contemporary scanning techniques. Therefore there is a need for images of early anatomical developmental to improve our understanding of this area. By using new imaging techniques, we can not only obtain better images to further our knowledge of early embryonic development, but clear images of embryonic and fetal development can also be used in training for e.g. sonographers and fetal surgeons, or to educate parents expecting a child with a fetal anomaly. The aim of this review is to provide an overview of the past, present and future techniques used to capture images of the developing human embryo and fetus and provide the reader newest insights in upcoming and promising imaging techniques. The reader is taken from the earliest drawings of da Vinci, along the advancements in the fields of in utero ultrasound and MR imaging techniques towards high-resolution ex utero imaging using Micro-CT and ultra-high field MRI. Finally, a future perspective is given about the use of artificial intelligence in ultrasound and new potential imaging techniques such as synchrotron radiation-based CT to increase our knowledge regarding human development.

The Neuroanatomy of Pregnancy and Postpartum

Pregnancy and giving birth are exceptional states in a woman's life for many reasons. While the effects of pregnancy and childbirth on the female body are obvious, less is known about their impact on the female brain, especially in humans. The scientific literature is still sparse but we have identified 12 longitudinal neuroimaging studies conducted in women whose brains were scanned before pregnancy, during pregnancy, and/or after giving birth. This review summarizes and discusses the reported neuroanatomical changes during pregnancy, postpartum, and beyond. Some studies suggest that pregnancy is mainly associated with tissue decreases, and a few studies suggest that this tissue loss is mostly permanent. In contrast, the majority of studies seems to indicate that the postpartum period is accompanied by substantial tissue increases throughout the entire brain. Future research is clearly warranted to replicate and extend the current findings, while addressing various limitations and shortcomings of existing studies.

Fetal MRI Neuroradiology: Indications

Fetal MRI is a safe, noninvasive examination of the fetus and placenta, a complement to ultrasonography. MRI provides detailed CNS evaluation, including depicting parenchymal architecture and posterior fossa morphology, and is key in prenatal assessment of spinal dysraphism, neck masses, and ventriculomegaly. Fetal MRI is typically performed after 22 weeks gestation, and ultrafast T1 and T2-weighted MRI sequences are the core of the exam, with advanced sequences such as diffusion weighted imaging used for specific questions. The fetal brain grows and develops rapidly, and familiarity with gestational age specific norms is essential to MRI interpretation.

Fetal Cardiovascular MRI - A Systemic Review of the Literature: Challenges, New Technical Developments, and Perspectives

BACKGROUND

Fetal magnetic resonance imaging (MRI) has become a valuable adjunct to ultrasound in the prenatal diagnosis of congenital pathologies of the central nervous system, thorax, and abdomen. Fetal cardiovascular magnetic resonance (CMR) was limited, mainly by the lack of cardiac gating, and has only recently evolved due to technical developments.

METHOD

A literature search was performed on PubMed, focusing on technical advancements to perform fetal CMR. In total, 20 publications on cardiac gating techniques in the human fetus were analyzed.

RESULTS

Fetal MRI is a safe imaging method with no developmental impairments found to be associated with in utero exposure to MRI. Fetal CMR is challenging due to general drawbacks (e. g., fetal motion) and specific limitations such as the difficulty to generate a cardiac gating signal to achieve high spatiotemporal resolution. Promising technical advancements include new methods for fetal cardiac gating, based on novel post-processing approaches and an external hardware device, as well as motion compensation and acceleration techniques.

CONCLUSION

Newly developed direct and indirect gating approaches were successfully applied to achieve high-quality morphologic and functional imaging as well as quantitative assessment of fetal hemodynamics in research settings. In cases when prenatal echocardiography is limited, e. g., by an unfavorable fetal position in utero, or when its results are inconclusive, fetal CMR could potentially serve as a valuable adjunct in the prenatal assessment of congenital cardiovascular malformations. However, sufficient data on the diagnostic performance and clinical benefit of new fetal CMR techniques is still lacking.

KEY POINTS

· New fetal cardiac gating methods allow high-quality fetal CMR.. · Motion compensation and acceleration techniques allow for improvement of image quality.. · Fetal CMR could potentially serve as an adjunct to fetal echocardiography in the future..

CITATION FORMAT

· Knapp J, Tavares de Sousa M, Schönnagel BP. Fetal Cardiovascular MRI - A Systemic Review of the Literature: Challenges, New Technical Developments, and Perspectives. Fortschr Röntgenstr 2022; 194: 841 - 851.

Fetal Brain Anatomy

"Fetal brain development has been well studied, allowing for an ample knowledge of the normal changes that occur during gestation. Imaging modalities used to evaluate the fetal central nervous system (CNS) include ultrasound and MRI. MRI is the most accurate imaging modality for parenchymal evaluation and depiction of developmental CNS anomalies. The depiction of CNS abnormalities in a fetus can only be accurately made when there is an understanding of its normal development. This article reviews the expected normal fetal brain anatomy and development during gestation. Additional anatomic structures seen on brain imaging sequences are also reviewed."

Imaging the acute abdomen in pregnancy: a radiological decision-making tool and the role of MRI

Acute abdominal pain in pregnancy poses a significant diagnostic challenge. The differential diagnosis is wide, clinical assessment is difficult, and the use of conventional imaging methods is restricted due to risks to the fetus. This can lead to delay in diagnosis, which increases the risk of maternal and fetal harm. Imaging techniques not involving ionising radiation are preferred. Sonography remains first line, but anatomical visualisation can be limited due to displacement of adjacent structures by the gravid uterus. MRI provides excellent cross-sectional soft-tissue assessment of the abdomen and pelvis, and no study to date has demonstrated significant deleterious effects to the fetus at any gestation; however, there remains a theoretical risk of tissue heating by radiofrequency pulses, and there must be consideration of benefit versus potential risk for any use of magnetic resonance imaging (MRI) in pregnancy. With a limited protocol of sequences, a broad spectrum of pathologies can be evaluated. Computed tomography carries the highest exposure of ionising radiation to the fetus, but may be necessary, particularly in cases of trauma. The patient must be kept informed and any potential risks to the patient and fetus should be clearly explained. We present a radiological decision-making tool to guide choice of imaging and best establish the underlying diagnosis in the acute pregnant abdomen. In addition, using illustrative examples from our practice at a large tertiary centre, we review the advantages and disadvantages of each imaging method, with particular focus on the utility of MRI.

A computerized diagnostic model for automatically evaluating placenta accrete spectrum disorders based on the combined MR radiomics-clinical signatures

We aimed to establish a computerized diagnostic model to predict placenta accrete spectrum (PAS) disorders based on T2-weighted MR imaging. We recruited pregnant women with clinically suspected PAS disorders between January 2015 and December 2018 in our institution. All preoperative T2-weighted imaging (T2WI) MR images were manually outlined on the picture archive communication system terminal server. A nnU-Net network for automatic segmentation and the corresponding radiomics features extracted from the segmented region were applied to build a radiomics-clinical model for PAS disorders identification. Taking the surgical or pathological findings as the reference standard, we compared this computerized model’s diagnostic performance in detecting PAS disorders. In the training cohort, our model combining both radiomics and clinical characteristics yielded an accuracy of 0.771, a sensitivity of 0.854, and a specificity of 0.750 in identifying PAS disorders. In the testing cohort, this model achieved a segmentation mean Dice coefficient of 0.890 and yielded an accuracy of 0.825, a sensitivity of 0.830 and a specificity of 0.822. In the external validation cohort, this computer-aided diagnostic model yielded an accuracy of 0.690, a sensitivity of 0.929 and a specificity of 0.467 in identifying placenta increta. In the present study, a machine learning model based on preoperative T2WI-based imaging had high accuracy in identifying PAS disorders in respect of surgical and histological findings.