Canadian Association of Radiologists Recommendations for the Safe Use of MRI During Pregnancy

Routine MR Imaging Protocol and Standardization in Central Nervous System Demyelinating Diseases

Standardized MR imaging protocols are important for the diagnosis and monitoring of patients with multiple sclerosis (MS) and the appropriate use of MR imaging in routine clinical practice. Advances in using MR imaging to establish an earlier diagnosis of MS, safety concerns regarding intravenous gadolinium-based contrast agents, and the value of spinal cord MR imaging for diagnostic, prognostic, and monitoring purposes suggest a changing role of MR imaging for the management and care of MS patients. The MR imaging protocol emphasizes 3 dimensional acquisitions for optimal comparison over time.

CETARS/CAR Practice Guideline on Imaging the Pregnant Trauma Patient

Imaging of pregnant patients who sustained trauma often causes fear and confusion among patients, their families, and health care professionals regarding the potential for detrimental effects from radiation exposure to the fetus. Unnecessary delays or potentially harmful avoidance of the justified imaging studies may result from this understandable anxiety. This guideline was developed by the Canadian Emergency, Trauma and Acute Care Radiology Society (CETARS) and the Canadian Association of Radiologists (CAR) Working Group on Imaging the Pregnant Trauma Patient, informed by a literature review as well as multidisciplinary expert panel opinions and discussions. The working group included academic subspecialty radiologists, a trauma team leader, an emergency physician, and an obstetriciangynaecologist/maternal fetal medicine specialist, who were brought together to provide updated, evidence-based recommendations for the imaging of pregnant trauma patients, including patient safety aspects (eg, radiation and contrast concerns) and counselling, initial imaging in maternal trauma, specific considerations for the use of fluoroscopy, angiography, and magnetic resonance imaging. The guideline strives to achieve clarity and prevent added anxiety in an already stressful situation of injury to a pregnant patient, who should not be imaged differently.

Canadian Association of Radiologists Cardiovascular Imaging Referral Guideline

The Canadian Association of Radiologists (CAR) Cardiovascular Expert Panel is made up of physicians from the disciplines of radiology, cardiology, and emergency medicine, a patient advisor, and an epidemiologist/guideline methodologist. After developing a list of 30 clinical/diagnostic scenarios, a rapid scoping review was undertaken to identify systematically produced referral guidelines that provide recommendations for one or more of these clinical/diagnostic scenarios. Recommendations from 48 guidelines and contextualization criteria in the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) for guidelines framework were used to develop 125 recommendation statements across the 30 scenarios (27 unique scenarios as 2 scenarios point to the CAR Thoracic Diagnostic Imaging Referral Guideline and the acute pericarditis subscenario is included under 2 main scenarios). This guideline presents the methods of development and the referral recommendations for acute chest pain syndromes, chronic chest pain, cardiovascular screening and risk stratification, pericardial syndromes, intracardiac/pericardial mass, suspected valvular disease cardiomyopathy, aorta, venous thrombosis, and peripheral vascular disease.

Updates on the management of inflammatory bowel disease from periconception to pregnancy and lactation

Inflammatory bowel disease (IBD) affects reproductive planning due to psychological effects and mechanical problems related to surgery. Children of people with IBD have an increased risk of about 10% if one parent has IBD and up to 33% if both parents have IBD. The fertility of people with IBD is similar to the general population, but fertility might be reduced in individuals with active IBD, ileal pouch-anal anastomosis, or perianal Crohn's disease. Flaring disease during pregnancy increases complications, such as preterm birth. Thus, disease management with appropriate medications can optimise outcomes. As most medications have minimal fetal risks, people with IBD should be informed about the risks of stopping medications and the importance of maintaining remission. A period of disease remission is advisable before pregnancy and could reduce the risks for both the pregnant person and the fetus. Flexible endoscopy, intestinal ultrasound, and gadolinium-free magnetic resonance enterography are safe during pregnancy. We provide state-of-the-art knowledge on the basis of the latest evidence to ensure successful pregnancy outcomes in controlled IBD.

Perceptions of Magnetic Resonance Imaging During Pregnancy: A Newfoundland and Labrador Perspective

OBJECTIVES

This study aimed to identify enablers and barriers to participation in MRI for clinical indications and scientific research, and to determine the perceptions of MRI performed during pregnancy.

METHODS

We conducted a survey of 156 pregnant people in Newfoundland and Labrador including sociodemographic information, obstetrical history, MRI history, and willingness to participate in an MRI. Categorical variables were analyzed using a Fisher exact test and open-ended questions were analyzed using thematic analysis.

RESULTS

In total, 80% of participants reported willingness to receive an MRI while pregnant for clinical indications compared to 24% for research. Only 10% reported prior knowledge about MRI during pregnancy and most participants (94%) wanted additional information from their physician before feeling comfortable with the procedure. Participants who knew someone with complications during pregnancy were more likely to be willing to participate in an MRI for research (uncorrected P < 0.05). Participants' positive perceptions towards MRI during pregnancy for clinical indications were that it was a necessary and useful procedure, while the negative perceptions identified MRI as unsafe. For research MRI, participants' positive perceptions included that it would add to the advancement of knowledge and the negative perceptions were that it was an unnecessary and risky procedure.

CONCLUSIONS

Strategies are needed to improve patient knowledge about the benefits and safety of MRI during pregnancy. The present study suggests recruitment for research should incorporate education on safety concerns and relative risk, personal stories about the benefits of MRI in diagnosing pregnancy complications and should highlight the contribution to advancing scientific knowledge.

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.

AFNet Algorithm for Automatic Amniotic Fluid Segmentation from Fetal MRI

Amniotic Fluid Volume (AFV) is a crucial fetal biomarker when diagnosing specific fetal abnormalities. This study proposes a novel Convolutional Neural Network (CNN) model, AFNet, for segmenting amniotic fluid (AF) to facilitate clinical AFV evaluation. AFNet was trained and tested on a manually segmented and radiologist-validated AF dataset. AFNet outperforms ResUNet++ by using efficient feature mapping in the attention block and transposing convolutions in the decoder. Our experimental results show that AFNet achieved a mean Intersection over Union (mIoU) of 93.38% on our dataset, thereby outperforming other state-of-the-art models. While AFNet achieves performance scores similar to those of the UNet++ model, it does so while utilizing merely less than half the number of parameters. By creating a detailed AF dataset with an improved CNN architecture, we enable the quantification of AFV in clinical practice, which can aid in diagnosing AF disorders during gestation.

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.

Bridging the Gap: Pregnancy-And Lactation-Associated Osteoporosis

Early diagnosis of pregnancy- and lactation-associated osteoporosis (PLO) is mandatory for a good outcome. Standard care is not a matter of conventional guidelines, rather it requires an individualized strategy while true overall incidence and pathogeny remain open issues. This is a narrative review based on full-length English articles, published between January 2021 and March 2023 and accessed via PubMed (no traumatic fractures or secondary osteoporosis are included). Our case-sample-based analysis included 836 females with PLO (the largest cohort based on published cases so far) through 12 studies and 24 single case reports. Except for one survey, these involved retrospective cohorts of small size (6-10 females/study) to medium size (23-47 women/study), and large cohorts with >50 subjects per study (a maximum of 379). Age of diagnosis: from 24 to 40 years for case reports (most subjects being over 30 and primigravida), while original studies indicated an average age between 31 and 34.18 years. Type of fractures underlined a most frequent vertebral phenotype (a mean of 2 to 5.8 vertebral fractures per patient) versus a most severe non-vertebral phenotype (hip and femoral neck fractures mostly requiring surgery). Potential contributors varied: smoking (1/3-1/2 of subjects), family history of osteoporosis (1/3), heparin and glucocorticoid use in pregnancy, low body mass index (majority of cases), hypovitaminosis D; and (with a low level of statistical significance) anti-psychotic medication, gestational diabetes, lupus, thrombophilia, anemia, in vitro fertilization (1/3 in one study), twin pregnancy, tocolysis with MgSO4, and postpartum thyroiditis. Most remarkably, up to 50% of PLO patients harbor mutations of LRP5, WNT1, and COL1A1/A2 (more damaged form with potential benefits from osteoanabolic drugs); gene testing might become the new norm in PLO. The low index of clinical suspicion should be supported by performing magnetic resonance imaging (gold standard in pregnancy) with DXA (in lactation). Low bone mineral density is expected (Z-score varying from -2.2 SD to -4 SD, unless normal which does not exclude PLO). Bone turnover markers might be useful in individuals with normal DXA, in pregnancy when DXA cannot be performed, and in following the response to anti-osteoporosis drugs. Alternatively, microarchitecture damage might be reflected by DXA-trabecular bone score and high-resolution peripheral quantitative computed tomography. Specific medical interventions are currently focused on teriparatide (TPT) use (3 studies; n = 99 females treated with TPT and an additional subgroup of 18 patients from the gene-analysis-based study, thus a total of 117 females) which seems to be the therapy of choice as reflected by these new data: 6-24 months, 20 µg/day, no sequential therapy needed; case selection based on high fracture risk is necessary). The first case using romosozumab was reported in 2022. PAO/LAO remains a challenging condition which is a battle for the wellbeing of two individuals, on one hand, considering maternal-fetal outcomes and taking care of the offspring, but it is a battle for a multidisciplinary team, on the other hand, since a standardized approach is lacking.

Gadolinium-Based Contrast Agents in Pregnant Women: A Literature Review of MRI Safety

Gadolinium-based contrast agents (GBCAs) are commonly used in magnetic resonance imaging (MRI) to enhance the visualisation and characterisation of the region of interest/lesion. Internal structures are well seen with MRI with good spatial resolution. Although MRI is generally considered safe during pregnancy, concerns have been raised regarding the safety of GBCAs, particularly during the first trimester. Limited studies have been conducted to assess the safety of GBCAs in pregnant women, with conflicting results. A comprehensive literature search was conducted using PubMed, SpringerLink, Medscape, ResearchGate and Wiley Online Library. The search terms included various combinations of MRI, pregnancy, first trimester, gadolinium contrast agents, foetus, risk, and toxicity. The search criteria were articles published in English in the last 20 years and indexed in the MEDLINE or Embase databases. The majority of studies found no definitive evidence that GBCAs are harmful during pregnancy, particularly during the first trimester. Some studies reported no increased risk of adverse outcomes in infants exposed to GBCAs during the first trimester. However, other studies showed inconsistent results. Retrospective cohort studies provided some reassurance regarding the safety of GBCAs when indicated in pregnant women but did not address potential long-term adverse outcomes in infants exposed to GBCAs during gestation. The literature review also highlights the importance of further evaluating the subacute and chronic effects of GBCA exposure in infants. The safety of GBCAs during pregnancy, particularly during the first trimester, remains uncertain. More large-scale, long-term studies are needed to clarify the safety of GBCAs in pregnant women and their potential effects on foetal and neonatal outcomes. Until conclusive evidence is available, healthcare providers should carefully weigh the benefits and risks of using GBCAs during pregnancy and consider alternative imaging modalities, such as non-contrast MRI or ultrasound, when necessary.

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.

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.

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.

Clinical advances: pregnancy in gastroenterologic and hepatic conditions

The fields of gastroenterology and hepatology, along with endoscopic practice, have seen significant changes and innovations to practice in just the past few years. These practice changes are not limited to gastroenterology, but maternal fetal medicine and the care of the pregnant person have become increasingly more sophisticated as well. Gastroenterologists are frequently called on to provide consultative input and/or perform endoscopy during pregnancy. To be able to provide the best possible care to these patients, gastroenterologists need to be aware of (and familiar with) the various nuances and caveats related to the care of pregnant patients who either have underlying gastrointestinal (GI) conditions or present with GI and liver disorders. Here, we offer a clinical update with references more recent than 2018, along with a few words about SARS-CoV-2 infection and its relevance to pregnancy.

Medical microrobots in reproductive medicine from the bench to the clinic

Medical microrobotics is an emerging field that aims at non-invasive diagnosis and therapy inside the human body through miniaturized sensors and actuators. Such microrobots can be tethered (e.g., smart microcatheters, microendoscopes) or untethered (e.g., cell-based drug delivery systems). Active motion and multiple functionalities, distinguishing microrobots from mere passive carriers and conventional nanomedicines, can be achieved through external control with physical fields such as magnetism or ultrasound. Here we give an overview of the key challenges in the field of assisted reproduction and how these new technologies could, in the future, enable assisted fertilization in vivo and enhance embryo implantation. As a case study, we describe a potential intervention in the case of recurrent embryo implantation failure, which involves the non-invasive delivery of an early embryo back to the fertilization site using magnetically-controlled microrobots. As the embryo will be in contact with the secretory oviduct fluid, it can develop under natural conditions and in synchrony with the endometrium preparation. We discuss the potential microrobot designs, including a proper selection of materials and processes, envisioning their translation from bench to animal studies and human medicine. Finally, we highlight regulatory and ethical considerations for bringing this technology to the clinic.

Risk of fetal or neonatal death or neonatal intensive care unit admission associated with gadolinium magnetic resonance imaging exposure during pregnancy

BACKGROUND

Concerns have been raised about prenatal exposure to magnetic resonance imaging with gadolinium-based contrast agents because of nonclinical findings of gadolinium retention in fetal tissue and 1 population-based study reporting an association with adverse pregnancy outcomes.

OBJECTIVE

This study aimed to evaluate the association between prenatal magnetic resonance imaging exposure with and without gadolinium-based contrast agents and fetal and neonatal death and neonatal intensive care unit admission.

STUDY DESIGN

We constructed a retrospective cohort of >11 million Medicaid-covered pregnancies between 1999 and 2014 to evaluate the association between prenatal magnetic resonance imaging exposure with and without gadolinium-based contrast agents and fetal and neonatal death (primary endpoint) and neonatal intensive care unit admissions (secondary endpoint). Medicaid claims data were linked to medical records, Florida birth and fetal death records, and the National Death Index to validate the outcomes and gestational age estimates. Pregnancies with multiples, concurrent cancer, teratogenic drug exposure, magnetic resonance imaging focused on fetal or pelvic evaluation, undetermined gadolinium-based contrast agent use, or those preceded by or contemporaneous with congenital anomaly diagnoses were excluded. We adjusted for potential confounders with standardized mortality ratio weighting using propensity scores.

RESULTS

Among 5991 qualifying pregnancies, we found 11 fetal or neonatal deaths in the gadolinium-based contrast agent magnetic resonance imaging group (1.4%) and 73 in the non-gadolinium-based contrast agent magnetic resonance imaging group (1.4%) with an adjusted relative risk of 0.73 (95% confidence interval, 0.34-1.55); the neonatal intensive care unit admission adjusted relative risk was 1.03 (0.76-1.39). Sensitivity analyses investigating the timing of magnetic resonance imaging or repeat magnetic resonance imaging exposure during pregnancy and simulating the impact of exposure misclassification corroborated these results.

CONCLUSION

This study addressed the safety concerns related to prenatal exposure to gadolinium-based contrast agents used in magnetic resonance imaging and the risk thereof on fetal and neonatal death or the need for neonatal intensive care unit admission. Although the results on fatal or severe acute effects are reassuring, the impact on subacute outcomes was not evaluated.

Lower-limb progressive paraparesis management and diagnosis overview in a pregnant woman with vertebral haemangioma

Vertebral haemangioma is a benign vascular tumour mostly seen in the thoracic region of the spine. Spinal haemangiomas are usually asymptomatic and are discovered incidentally. In a few patients, however, aggressive vertebral haemangiomas can cause local pain, radicular pain or neurologic deficits, which result from neural compression. The aetiology of the origin is unclear and is probably multifactorial. Hormonal and biological changes in pregnant women can lead to accelerated vascular growth of haemangioma. In our report, we present the case of a pregnant patient who was diagnosed with an aggressive vertebral haemangioma that further led to progressive paraparesis. We had to take the fact that she was pregnant into account in the diagnostic procedure, in the choice of examination method and also in the method of therapy. The goal of this case report is threefold: (1) provide an overview of the possible methods of management, specifically imaging, which will aid in diagnosis and based on that, (2) determining the appropriate therapy and (3) review the risks and benefits of each will be presented when choosing individual approaches.

Neuroradiologie für den Augenarzt

Zu den neuroophthalmologischen Erkrankungen gehören Läsionen der Sehbahn einschließlich der Retina und des Sehnervs, Anomalien der Augenstellung und/oder -motilität sowie Pupillenstörungen 1. CT und MRT spielen bei der Diagnosestellung, der Ausbreitung eines Krankheitsprozesses und differenzialdiagnostischen Überlegungen eine herausragende Rolle. Ziel dieses Fortbildungsartikels ist es, dem Augenarzt einen Überblick über diese Untersuchungsverfahren und ihren Einsatz bei für den Augenarzt relevanten Erkrankungen zu geben.

[Neuroradiology for the Ophthalmologist]

Computer tomography (CT) and magnet resonance imaging (MRI) are valuable imaging tools in order to examine various pathologies of the visual pathways. The advantage of CT is its short acquisition time of a few minutes, its availability making it an ideal tool in emergency medicine. It is extremely valuable in patients with cranio-cerebral trauma when an orbital or skull fracture or an intracerebral haemorrhage has to be assessed. In addition, CT-Angiography is used in the management of patients with an acute stroke. CT is mandatory to visualize the orbit in many conditions. The most important disadvantage is its use of ionizing radiation. Thus, CT is contraindicated in pregnant woman. Contrast of soft tissue as brain tissue is inferior compared to MRI. The latter has a high sensitivity in visualizing all kind of brain pathologies including tumours, inflammatory conditions or brain oedema as a result of a stroke. In contrast to CT, MRI (without contrast agent) can be used in pregnant women. The disadvantages of MRI are its long acquisition time, its contraindication in patients with metallic implants including pacemaker and its low resolution of bony tissue. Both imaging tools are often used in a complementary way in many orbital diseases, pathologies affecting bony structures, pathologies with calcifications and in stroke patients.