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BACKGROUND: Fetal dedicated echocardiography is the standard to measure the fetal cardiac axis. However, fetal screening ultrasound (US) or fetal dedicated echocardiography may be technically limited. OBJECTIVE: The purpose of this study was to explore the accuracy of fetal cardiac magnetic resonance imaging (MRI) to measure the cardiac axis in fetuses with congenital heart disease as an adjunct to fetal dedicated echocardiography and to assess the predictive value of fetal cardiac MRI measurements in distinguishing healthy fetuses from fetuses with congenital heart disease. MATERIALS AND METHODS: This is a retrospective study of fetuses referred to our hospital for a fetal cardiac MRI from November 2019 to December 2021. Cardiac axes were measured in the 4-chamber view of the fetal heart using fetal cardiac MRI and dedicated echocardiography, or only using fetal cardiac MRI when screening US was technically limited. The fetuses were divided into a congenital heart disease group and a healthy control group. We used Bland-Altman analysis and the intraclass correlation coefficient (ICC) to assess the agreement of cardiac axis measurements in fetuses with congenital heart disease obtained by cardiac MRI and by fetal dedicated echocardiography. Receiver operating characteristic (ROC) curve analysis of the fetal cardiac axes in the congenital heart disease and healthy fetus groups assessed the predictive value of the cardiac axis measurements. RESULTS: This retrospective study included 431 women (162 carrying fetuses with congenital heart disease, 269 carrying healthy fetuses). Cardiac axes were measured in the 162 fetuses with congenital heart disease using fetal cardiac MRI and dedicated echocardiography. Cardiac axes were measured in the 269 healthy control fetuses using fetal cardiac MRI when fetal screening US was technically limited. The interobserver analysis and intraobserver analysis showed that the cardiac axis measured by fetal cardiac MRI and fetal dedicated echocardiography was repeatable (ICC>0.90). In 162 fetuses with congenital heart disease, Bland-Altman analysis showed a strong agreement between cardiac MRI and fetal dedicated echocardiography measurements for the cardiac axis. The ICC for the cardiac axis values between cardiac MRI and fetal dedicated echocardiography measurements was 0.99. In fetuses with congenital heart disease, 64.2% (104/162) had an abnormal cardiac axis. For the fetal cardiac axis in both the 162 fetuses with congenital heart disease and the 269 healthy fetuses, the area under the ROC curve reached 0.85 (95% confidence interval: 0.80-0.89; P<0.0001). CONCLUSION: The cardiac axis can be accurately measured using fetal cardiac MRI when fetal dedicated echocardiography/fetal screening US is technically limited. The cardiac axis measurements by fetal cardiac MRI are consistent with known cardiac axis measurements by fetal dedicated echocardiography. The frequency of abnormal cardiac axis depends on the type of congenital heart disease.
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Cardiopatias Congênitas , Gravidez , Feminino , Humanos , Estudos Retrospectivos , Cardiopatias Congênitas/diagnóstico por imagem , Imageamento por Ressonância Magnética , Diagnóstico Pré-Natal , Coração Fetal/diagnóstico por imagem , Coração Fetal/patologia , Ultrassonografia Pré-Natal/métodosRESUMO
OBJECTIVE: The purpose of this retrospective study was to report our cases of fetal ectopia cordis (EC) and to evaluate the utility of fetal cardiovascular magnetic resonance imaging (MRI) for the diagnosis of this rare anomaly. METHOD: This retrospective study included 11 fetuses with EC. The multiplane steady-state free precession (SSFP) sequence, single-shot turbo spin-echo sequence and non-gated SSFP cine cardiovascular magnetic resonance were used to evaluate the fetal heart and abdomen. RESULTS: The 11 fetal cases with EC were examined by fetal cardiovascular MRI and confirmed by postnatal or post-mortem findings. Of these 11 cases, two were isolated thoracic EC, six had pentalogy of Cantrell, and three had an omphalocele and EC. Among all 11 fetuses, nine were associated with congenital heart defects. In four cases, fetal MRI added additional information compared to fetal ultrasound, however, in two cases, fetal MRI missed the diagnosis of a ventricular septal defect noted by echocardiography. CONCLUSION: Fetal MRI combined with prenatal echocardiography can improve the accuracy of the prenatal diagnosis of EC.
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Ectopia Cordis , Cardiopatias Congênitas , Gravidez , Feminino , Humanos , Ectopia Cordis/diagnóstico por imagem , Estudos Retrospectivos , Diagnóstico Pré-Natal/métodos , Coração Fetal/diagnóstico por imagem , Ultrassonografia Pré-Natal/métodos , Cardiopatias Congênitas/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodosRESUMO
BACKGROUND: Several published studies have shown alterations of brain development in third-trimester fetuses with congenital heart disease (CHD). However, little is known about the timing and pattern of altered brain development in fetuses with CHD. PURPOSE: To investigate the changes in the volume of intracranial structures in fetuses with CHD by three-dimensional (3D) volumetric magnetic resonance imaging (MRI) in the earlier stages of pregnancy (median gestational age [GA], 26 weeks). STUDY TYPE: Retrospective. POPULATION: Forty women carrying a fetus with CHD (including 20 fetuses with GA <26 weeks) and 120 pregnant women carrying a healthy fetus (including 50 fetuses with GA <26 weeks). FIELD STRENGTH/SEQUENCE: Two-dimensional single-shot turbo spin echo sequence at 1.5 -T. ASSESSMENT: Three-dimensional volumetric parameters from slice-to-volume registered images, including cortical gray matter volume (GMV), subcortical brain tissue volume (SBV), intracranial cavity volume (ICV), lateral ventricles volume (VV), cerebellum, brainstem, and extra-cerebrospinal fluid (e-CSF) were quantified by manual segmentation from one primary and two secondary observers. STATISTICAL TESTS: Volumes were presented graphically with quadratic curve fitting. Scatterplots were produced mapping volumes against GA in normal and CHD fetuses. For GA <26 weeks, Z scores were calculated and Student's t-tests were conducted to compare volumes between the normal and CHD fetuses. RESULTS: In fetuses with CHD GMV, SBV, cerebellum, and brainstem were significantly reduced (all P < 0.05) in early stages of pregnancy (GA <26 weeks), with differences becoming progressively greater with increasing GA. Compared with normal fetuses, e-CSF, e-CSF to ICV ratio, and VV were higher in fetuses with CHD (all P < 0.05). However, ICV volume and the GMV to SBV ratio were not significantly reduced in the CHD group (P = 0.94 and P = 0.13, respectively) during the middle gestation (GA <26 weeks). DATA CONCLUSION: There appear to be alterations of brain development trajectory in CHD fetuses that can be detected by 3D volumetric MRI in the earlier stages of pregnancy. LEVEL OF EVIDENCE: 4 TECHNICAL EFFICACY: Stage 3.
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Cardiopatias Congênitas , Diagnóstico Pré-Natal , Encéfalo/diagnóstico por imagem , Feminino , Feto , Cardiopatias Congênitas/diagnóstico por imagem , Humanos , Imageamento Tridimensional , Lactente , Imageamento por Ressonância Magnética , Gravidez , Estudos RetrospectivosRESUMO
Rare and endangered plants (REPs) and their associated endophytes survived in unique habitats are promising sources for natural product-derived drug discovery. In this study, six new (cephaloverines A-F, 1-6, resp.) and 16 known (11-26) cephalotaxine-type alkaloids, together with three new (oliverbiflavones A-C, 7-9, resp.) and 11 known (27-37) biflavonoids were isolated and characterized from the twigs and leaves of Cephalotaxus oliveri, an endangered plant endemic to China. Meanwhile, a preliminary investigation on the secondary metabolites from a selected fungal endophyte (i.e., Alternaria alternate Y-4-2) associated with the title plant led to the isolation of 21 structurally distinct polyketides including one new dimeric xanthone (10). The new structures (1-10) with the absolute configurations were determined by detailed spectroscopic analyses, electronic circular dichroism (ECD) or Na2MoO4-induced ECD, the modified Mosher's method, and some chemical transformations. Compounds 1-4 are the first representatives of naturally occurring N-oxides of cephalotaxine esters, while compounds 7-9 have a special structural feature of having a C-methylated biflavonoid skeleton. The Cephalotaxus alkaloids with ester side-chains at C-3 (1-6, 13-22, and 26) and four biflavonoids (27-29 and 34) were found to show pronounced cytotoxicities against a small panel of human cancer cell lines (A549, NCI-H460, HL60, NCI-H929, and RPMI-8226), with IC50 values mainly ranging from 0.003 to 9.34 µM. The most potent compound, deoxyharringtonine (16), generally exhibited IC50 values less than 10 nM. The structure-activity relationship (SAR) of the aforementioned Cephalotaxus alkaloids was briefly discussed.
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Alternaria/efeitos dos fármacos , Antineoplásicos/isolamento & purificação , Biflavonoides/isolamento & purificação , Cephalotaxus/química , Folhas de Planta/química , Antineoplásicos/farmacologia , Biflavonoides/farmacologia , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Endófitos , Mepesuccinato de Omacetaxina/química , Humanos , Estrutura Molecular , Policetídeos/química , Metabolismo Secundário , Relação Estrutura-Atividade , Xantonas/químicaRESUMO
MRI is used widely in infants and young children. However, in these young cases deep sedation or general anesthesia is often required to minimize motion artifacts during MRI examinations. Although the benefits of MR typically outweigh the potential risks of sedation when delivered by an experienced team, there are increasing concerns regarding the affect of sedation on young children. There continues to be a push to develop various strategies that can minimize the need for sedation. The present review summarizes several technical and clinical approaches that can help decrease the need for sedation in the pediatric patient. Optimization of the MRI environment, the role of child life specialists, feed-and-bundle and distraction techniques, noise-reduction methods, artificial intelligence, and MRI advances to decrease both scan times and motion artifacts will be discussed. Level of Evidence: 5 Technical Efficacy Stage: 1 J. Magn. Reson. Imaging 2019.
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Anestesia/métodos , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Imageamento por Ressonância Magnética/psicologia , Segurança do Paciente , Pediatria/métodos , Artefatos , Inteligência Artificial , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Ruído/prevenção & controleRESUMO
PURPOSE: To present three fetal vein of Galen aneurysmal malformations (VGAMs), which were diagnosed through magnetic resonance imaging (MRI), and highlight these cardiovascular findings. MATERIALS AND METHODS: We retrospectively reviewed three fetuses with VGAM at 31, 32, and 33 weeks of gestation. Feeding arteries and draining veins were observed by MRI. Secondary changes in the brain and high-output heart failure caused by high blood flow in the lesion were evaluated. Two fetuses were born, and neonatal MRI was performed. One fetus was terminated. RESULTS: A characteristic dilated structure in the midline of the brain presented in each fetus. The arteriovenous fistula led to anatomical brain changes such as in the hydrocephalus, dilated feeding vessels (one or more), jugular vein, and/or superior vena cava. Substantial brachiocephalic vessel dilation was observed in two fetuses. Following parturition, one baby had neonatal asphyxia and sinus thrombosis, and MRI revealed hypoxic-ischemic encephalopathy. Cardiomegaly was detected in all three cases. CONCLUSION: With a large field of view, fetal MRI can observe brain VGAM, as well as the heart and affected large vessels. It can determine hydrocephalus, ischemia, intracranial hemorrhage, and sinus thrombosis. Providing such information on the infant's entire body can aid clinicians in determining the most appropriate treatment. LEVEL OF EVIDENCE: 4 J. Magn. Reson. Imaging 2017;46:1535-1539.
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Cistos/diagnóstico por imagem , Imageamento por Ressonância Magnética , Diagnóstico Pré-Natal/métodos , Malformações da Veia de Galeno/diagnóstico por imagem , Adulto , Fístula Arteriovenosa , Encéfalo/diagnóstico por imagem , Veias Cerebrais , Evolução Fatal , Feminino , Insuficiência Cardíaca/diagnóstico por imagem , Humanos , Lactente , Recém-Nascido , Gravidez , Estudos RetrospectivosRESUMO
Fetal echocardiography is the imaging modality of choice for prenatal diagnosis of congenital cardiovascular anomalies. However, echocardiography has limitations. Fetal cardiac magnetic resonance imaging (MRI) has the potential to complement US in detecting congenital cardiovascular anomalies. This article draws on our experience; it describes the transverse aortic arch view on fetal cardiac MRI and important clues on an abnormal transverse view at the level of the aortic arch to the diagnosis of fetal congenital cardiovascular anomalies.
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Aorta Torácica/embriologia , Aorta Torácica/patologia , Coração Fetal/patologia , Cardiopatias Congênitas/diagnóstico , Imageamento por Ressonância Magnética , Diagnóstico Pré-Natal , Feminino , Humanos , GravidezRESUMO
Objective: There are differences in the vulnerability of male and female fetal brains to adverse intrauterine exposure, preterm birth, and associated perinatal brain injury. The main objective of this study was to identify any statistically significant difference in the change of apparent diffusion coefficient (ADC) in the intracranial regions of male and female fetuses in the second and third trimesters. Methods: Diffusion-weighted imaging (DWI) was performed in 200 fetuses between 20 and 37 gestational ages (GA) with normal results or suspicious results on sonography followed by structural MRI. Pairwise ADC values of the regions of interest (ROIs) were manually delineated on either side of the cerebral white matter: frontal white matter (FWM), parietal white matter (PWM), occipital white matter (OWM), temporal white matter (TWM), basal ganglia (BG), thalamus (THA), cerebellar hemisphere (CBM), and a single measurement in the pons. The changes in these values were studied over the gestational range, along with potential sex differences and asymmetries of the cerebral hemispheres. Results: During the third trimester, ADC values in OWM, TWM, and CBM were significantly higher in male fetuses than those in female fetuses (p < 0.05). After the correction of false-discovery rates (FDR), the difference in CBM was the only statistically significant (p = 0.0032). However, the decreased rate of ADC values in male fetuses in CWM (except for FWM), BG, THA, CBM, and pons was higher than that in female fetuses during the second and third trimesters. Conclusions: We have shown some differences in the intracranial regional ADC changes between male and female fetuses using in utero DWI during the second and third trimesters.
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BACKGROUND: The cardiovascular system is the part of the fetal anatomy that most frequently suffers from congenital pathology. This study shows our preliminary experience with fetal cardiovascular magnetic resonance (CMR) to evaluate congenital cardiovascular abnormalities. METHODS: Between January 2006 and June 2011, Prenatal routine obstetric ultrasound (US), echocardiography and CMR data from 68 pregnant women carrying fetuses with congenital cardiovascular anomalies were compared with postnatal diagnoses (postnatal imagings, surgery and autopsy). All prenatal CMR was performed at 1.5 T. Imaging sequences included steady-state free-precession (SSFP) sequences, real-time SSFP and single-shot turbo spin echo (SSTSE) sequences. The images were analyzed with an anatomic segmental approach by two radiologists. RESULTS: Fetal CMR yielded the same diagnosis as postnatal findings in 79% (54/68) of patients. The diagnostic sensitivity of routine obstetric US for cardiac anomalies was 46% (31/68). The diagnostic sensitivity of fetal echocardiographic examination by a fetal cardiac specialist was 82% (56/68). In 2 (3%) of 68 cases, diagnoses with both echocardiography and CMR were incorrect when compared with postnatal diagnosis. In ten (15%) cases, diagnosis at echocardiography was incorrect and that at CMR was correct. In twelve (18%) cases, diagnosis at echocardiography was correct and that at CMR was incorrect. Ten cases missed or misdiagnosed by echocardiography but correctly diagnosed by fetal CMR included asplenia syndrome (n = 2), interrupted inferior vena cava of polysplenia syndrome (n = 1), tricuspid incompetence (n = 1), double outlet right ventricle (n = 2), double aortic arch (n = 1), right pulmonary artery hypoplasia (n = 1), right-sided aortic arch of tetralogy of Fallot (n = 1) and hypoplastic left heart syndrome of a twin fetus (n = 1). CONCLUSION: Fetal CMR is a promising diagnostic tool for assessment of congenital cardiovascular abnormalities, especially in situations that limit echocardiography.
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Cardiopatias Congênitas/diagnóstico , Imageamento por Ressonância Magnética/métodos , Diagnóstico Pré-Natal/métodos , Adulto , Feminino , Cardiopatias Congênitas/diagnóstico por imagem , Humanos , Interpretação de Imagem Assistida por Computador , Gravidez , Sensibilidade e Especificidade , Ultrassonografia Pré-NatalRESUMO
Objective: This study aimed to report our experience in qualitative and quantitative evaluation of fetal complete vascular ring (CVR) using fetal cardiovascular magnetic resonance imaging (MRI) to improve prenatal diagnosis and make early postnatal management possible. Methods: A retrospective case-control study was performed on cases of CVR diagnosed using fetal cardiovascular MRI, and confirmed by postnatal imaging diagnosis. Associated abnormalities were recorded. The diameters of aortic arch isthmus (AoI) and ductus arteriosus (DA), and tracheal diameters in fetuses with tracheal compression were measured and compared with those of the control group. Results: All fetal CVR cases in this study included right aortic arch (RAA) with aberrant left subclavian artery (ALSA) and left DA (n = 93), double aortic arch (DAA) (n = 29), RAA with mirror-image branching and retroesophageal left ductus arteriosus (RLDA) (n = 8). Compared with the control group, the diameters of AoI in fetuses with DAA were decreased (p < 0.001), and the diameters of DA in fetuses with RAA with ALSA and left DA were increased (p < 0.001). The diameters of AoI and DA were positively correlated with gestational age (GA) in the normal control group (both p < 0.001); The diameters of AoI and DA were also positively correlated with GA in RAA with ALSA and left DA subgroup (both p < 0.001) and RAA with mirror-image branching and RLDA subgroup (AoI: p = 0.003; DA: p = 0.002); The diameters of DA were positively associated with GA in DAA subgroup (p < 0.001), however, there was no linear tendency between the diameters of AoI and GA in the DAA subgroup (p = 0.074). There were CVR fetuses with associated intracardiac malformation (n = 13), especially ventricular septal defect rather than complex heart disease, and extracardiac malformation (n = 14). Sixteen fetuses were shown the airway compression whose tracheal diameters were smaller than the normal (p < 0.001). Conclusions: The altered diameters of AoI and DA can be detected and measured in CVR fetuses using fetal cardiovascular MRI. Fetal CVR can occur alone or with intracardiac and extracardiac malformation. Fetal CVR can be associated with prenatal airway compression.
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Objective: The purpose of this study is to establish a reference of intracranial structure volumes in normal fetuses ranging from 19 to 37 weeks' gestation (mean 27 weeks). Materials and Methods: A retrospective analysis of 188 MRI examinations (1.5 T) of fetuses with a normal brain appearance (19-37 gestational weeks) from January 2018 to December 2021 was included in this study. Three dimensional (3-D) volumetric parameters from slice-to-volume reconstructed (SVR) images, such as total brain volume (TBV), cortical gray matter volume (GMV), subcortical brain tissue volume (SBV), intracranial cavity volume (ICV), lateral ventricles volume (VV), cerebellum volume (CBV), brainstem volume (BM), and extra-cerebrospinal fluid volume (e-CSFV), were quantified by manual segmentation from two experts. The mean, SD, minimum, maximum, median, and 25th and 75th quartiles for intracranial structures volume were calculated per gestational week. A linear regression analysis was used to determine the gestational weekly age-related change adjusted for sex. A t-test was used to compare the mean TBV and ICV values to previously reported values at each gestational week. The formulas to calculate intracranial structures volume derived from our data were created using a regression model. In addition, we compared the predicted mean TBV values derived by our formula with the expected mean TBV predicted by the previously reported Jarvis' formula at each time point. For intracranial volumes, the intraclass correlation coefficient (ICC) was calculated to convey association within and between observers. Results: The intracranial volume data are shown in graphs and tabular summaries. The male fetuses had significantly larger VV compared with female fetuses (p = 0.01). Measured mean ICV values at 19 weeks are significantly different from those published in the literature (p < 0.05). Means were compared with the expected TBV generated by the previously reported formula, showing statistically differences at 22, 26, 29, and 30 weeks' gestational age (GA) (all p < 0.05). A comparison between our data-derived formula and the previously reported formula for TBV showed very similar values at every GA. The predicted TBV means derived from the previously reported formula were all within the 95% confidence interval (CI) of the predicted means of this study. Intra- and inter-observer agreement was high, with an intraclass correlation coefficient larger than 0.98. Conclusion: We have shown that the intracranial structural volume of the fetal brain can be reliably quantified using 3-D volumetric MRI with a high degree of reproducibility and reinforces the existing data with more robust data in the earlier second and third stages of pregnancy.
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We report an efficient Au(I)-catalyzed formal allylation of diazo(thio)oxindoles using allyltrimethylsilane to give 3-allyl (thio)oxindoles, which are difficult to access by using traditional alkylation methods under basic conditions. The approach enables a highly stereoselective synthesis of quaternary (thio)oxindoles via a formal allylation-asymmetric Michael addition sequence. These adducts are versatile synthons for spirocyclic (thio)oxindoles. Initial biological studies reveal that chiral thiooxindoles show promising antiproliferation activity that is better than that of the corresponding oxindoles.
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Purpose: To determine the value of fetal magnetic resonance imaging (MRI) to detect renal duplication.Methods: In this retrospective study, prenatal MRI and ultrasound (US) diagnoses were compared with postnatal imaging and/or surgical data. Twenty-six pregnant women (average age, 32 years; range, 29-36 years) underwent MRI at a mean gestational age of 25 weeks (range, 21-33 weeks). MRI was performed with a 1.5-T unit within 1 week after prenatal ultrasound examination. The steady-state free-precession (SSFP), single-shot turbo spin echo (SSTSE), and T1-weighted fast imaging sequences were used.Results: Twenty-four cases of fetal renal duplications diagnosed using prenatal MRI were judged to be correct when compared with postnatal imaging and surgical follow-up. In 18 of 26 cases, the diagnoses established using prenatal US were correct when compared with postnatal diagnosis. In 2 of 26 cases, the diagnosis with both prenatal US and MRI were not entirely correct when compared with postnatal diagnosis. In the two cases, magnetic resonance (MR) identified left two pelvicalyceal systems but could not found ipsilateral ectopic ureteral orifice, US only found left hydronephrosis but could not found duplex collection system. In other six cases, MR corrected the US diagnosis by providing a more accurate renal morphology or additional diagnostic information.Conclusions: MRI is an effective method for the diagnosis of fetal duplex kidney deformity and associated ureteral and other abnormalities.
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Rim/diagnóstico por imagem , Rim/embriologia , Imageamento por Ressonância Magnética/métodos , Adulto , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Rim/anormalidades , Gravidez , Estudos Retrospectivos , Ultrassonografia Pré-Natal , Sistema Urinário/anormalidades , Sistema Urinário/diagnóstico por imagem , Sistema Urinário/embriologiaRESUMO
Unlike ultrasound (US) imaging, foetal magnetic resonance imaging (MRI) is not significantly limited by maternal obesity, oligohydramnios, uterine myoma, twins, and foetal lie, which impair US visualization of the foetus. The present study aimed to introduce our foetal cardiac MRI scanning technology and over 14-years of experience on the potential utility of foetal cardiac MRI examination as an adjunct to foetal technically inadequate echocardiography (Echo). This retrospective review included 1,573 pregnant women [1,619 foetuses (46 twins)] referred for a foetal cardiac MRI because of technically limited Echo. Foetal cardiac MRI was performed using two 1.5 T units. Among the 1,619 foetuses referred for cardiac MRI, 1,379 (85.2%) cases were followed up using postnatal imaging and/or surgery, 240 (14.8%), including three twins, had no follow-up confirmation because of pregnancy termination without autopsy or loss to follow-up. The results of the present study indicated that foetal cardiac MRI examinations can be a useful adjunct to foetal echocardiography when the technical limitations of echocardiography make it inadequate for diagnosis.
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Ecocardiografia , Coração Fetal/diagnóstico por imagem , Cardiopatias Congênitas/diagnóstico por imagem , Imageamento por Ressonância Magnética , Diagnóstico Pré-Natal , Ultrassonografia Pré-Natal , Adulto , Feminino , Seguimentos , Humanos , Gravidez , Gravidez de Gêmeos , Estudos Retrospectivos , GêmeosRESUMO
Alkene hydrodifluoroalkylation is a fruitful strategy for synthesizing difluoromethylated compounds that are interesting for developing new medicinal agents, agrochemicals, and advanced materials. Whereas the anti-Markovnikov hydrodifluoroalkylation to linear-type products is developed, employing radical-based processes, the Markovnikov synthesis of branched adducts remains unexplored. Herein, we describe acid-catalyzed processes involving carbocation intermediates as a promising strategy to secure the Markovnikov regioselectivity. Accordingly, the Markovnikov hydrodifluoroalkylation of mono-, di-, tri-, and tetrasubstituted alkenes using difluoroenoxysilanes, catalyzed by Mg(ClO4)2·6H2O, is achieved. This allows the diversity-oriented synthesis of α,α-difluoroketones with a quaternary or tertiary carbon at the ß-position that are otherwise difficult to access. The method is applied to the modification of natural products and drug derivatives. The resulting α,α-difluorinated ketones could be converted to the corresponding α,α-difluorinated esters or alcohols, or organofluorine compounds featuring a CF2H or CF2CF2Ph moiety. Mechanistic studies support that Mg(ClO4)2·6H2O functions as a hidden Brønsted acid catalyst.
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Retinoic acid can cause many types of cells, including mouse neuroblastoma Neuro-2A cells, to differentiate into neurons. However, it is still unknown whether microRNAs (miRNAs) play a role in this neuronal differentiation. To address this issue, real-time polymerase chain reaction assays were used to detect the expression of several differentiation-related miRNAs during the differentiation of retinoic acid-treated Neuro-2A cells. The results revealed that miR-124 and miR-9 were upregulated, while miR-125b was downregulated in retinoic acid-treated Neuro-2A cells. To identify the miRNA that may play a key role, miR-124 expression was regulated by transfection of miRNA mimics or inhibitors. Morphological analysis results showed that inhibition of miR-124 expression reversed the effects of retinoic acid on neurite outgrowth. Moreover, miR-124 overexpression alone caused Neuro-2A cells to differentiate into neurons, and its inhibitor could block this effect. These results suggest that miR-124 plays an important role in retinoic acid-induced differentiation of Neuro-2A cells.
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OBJECTIVE: To evaluate the utility of fetal cardiac magnetic resonance imaging (MRI) in diagnosing right aortic arch with mirror image branching and retroesophageal left ductus arteriosus (RLDA). METHODS: This retrospective study included six infants diagnosed with right aortic arch with mirror image branching and RLDA postnatally by cardiac computed tomography (CT) that had fetal echocardiography (echo) and MRI initially performed. The six fetal MRI cases were examined using 1.5 T MRI unit. Steady-state free precession (SSFP) sequence and single-shot turbo spin echo (SSTSE) sequence were used to evaluate the fetal great vessels and airway. The gestational age of six fetuses at time of fetal MRI ranged from 23 to 35 weeks (mean, 26.7 weeks). RESULTS: Of six cases with mirror image right aortic arch and RLDA confirmed by postnatal CT, 4/6 were correctly diagnosed by fetal cardiac MRI and 3/6 were correctly diagnosed by prenatal echo. All six cases were not associated with other congenital heart defect. All ductus arteriosus were closed after birth. CONCLUSIONS: Fetal cardiac MRI can be a useful adjunct for evaluating fetal right aortic arch with mirror-image and RLDA.
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Aorta Torácica/anormalidades , Canal Arterial/anormalidades , Coração Fetal/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Diagnóstico Pré-Natal/métodos , Adulto , Aorta Torácica/diagnóstico por imagem , Canal Arterial/diagnóstico por imagem , Feminino , Idade Gestacional , Humanos , Gravidez , Estudos Retrospectivos , Tomografia Computadorizada por Raios X , Ultrassonografia Pré-NatalRESUMO
The purpose of this study was to report fetal cases of subaortic and retroesophageal anomalous courses of the left brachiocephalic vein (LBCV) evaluated by fetal cardiac magnetic resonance imaging (MRI). A retrospective review of 7282 fetal cardiac MRI from June 2006 to March 2017, nine cases of anomalous courses of the LBCV were correctly diagnosed by fetal cardiac MRI, one case of abnormal subaortic left brachiocephalic vein (ASLBV) missed by fetal MRI was identified postnatally during further imaging of the TOF. The diagnosis was confirmed postnatally by cardiac CT/MRI. An ASLBV was found in 8 cases, a retroesophageal LBCV was found in 2 additional cases with right aortic arch and aberrant left subclavian artery. 3 of 8 ASLBV cases were with a right aortic arch, 4 ASLBV cases had additional cardiovascular anomalies with one case isolated. 7 of 8 ASLBV and 2 retroesophageal LBCV were correctly diagnosed by fetal cardiac MRI; however fetal cardiac MRI missed 2 cases of associated pulmonary atresia (PA). Prenatal echocardiography (echo) correctly diagnosed five ASLBV and one retroesophageal LBCV as well as associated intracardiac anomalies. Fetal cardiac MRI can be a useful adjunct in the identification of subaortic and retroesophageal anomalous courses of the LBCV prenatally.
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Veias Braquiocefálicas/diagnóstico por imagem , Anormalidades Cardiovasculares/diagnóstico por imagem , Cardiopatias Congênitas/diagnóstico por imagem , Artéria Subclávia/anormalidades , Malformações Vasculares/diagnóstico por imagem , Adulto , Aneurisma/diagnóstico , Aneurisma/diagnóstico por imagem , Aneurisma/patologia , Aorta Torácica/diagnóstico por imagem , Aorta Torácica/patologia , Veias Braquiocefálicas/patologia , Anormalidades Cardiovasculares/patologia , Ecocardiografia , Esôfago/diagnóstico por imagem , Esôfago/patologia , Feminino , Feto , Cardiopatias Congênitas/diagnóstico , Cardiopatias Congênitas/fisiopatologia , Humanos , Imageamento por Ressonância Magnética/normas , Mediastino/diagnóstico por imagem , Mediastino/patologia , Gravidez , Atresia Pulmonar/diagnóstico , Atresia Pulmonar/diagnóstico por imagem , Atresia Pulmonar/patologia , Artéria Subclávia/diagnóstico por imagem , Artéria Subclávia/patologia , Tomografia Computadorizada por Raios X , Ultrassonografia Pré-Natal , Malformações Vasculares/diagnóstico , Malformações Vasculares/patologiaRESUMO
We sought to evaluate the diagnostic value of foetal magnetic resonance imaging (MRI) for multicystic dysplastic kidney (MCDK) disease. We retrospectively identified 55 foetuses with MCDK diagnosed (51 unilateral; 4 bilateral) by foetal MRI. We analysed the anatomical findings by prenatal MRI and compared them with the prenatal ultrasound (US) and postnatal findings. Additional diagnostic information added by MRI was recorded. The gestational age of the 55 foetuses ranged from 22 to 35 weeks (mean, 26.5 ± 3.6 weeks). The age of the pregnant women ranged from 23 to 40 years (mean, 31 ± 4.2 years). All 55 cases were performed at 1.5 T magnetic resonance unit. MRI sequences, including steady-state free precession (SSFP), single-shot fast spin echo (SSFSE), T1-weighted imaging (T1WI), and diffusion weighted imaging (DWI) sequences. Follow-up was obtained for 53 cases (2 cases of autopsy, 51 cases of postnatal imaging or surgery confirmed). Among the 51 unilateral cases, 16 cases were associated with other urinary tract anomalies, 3 cases with extra-renal anomalies, and the remaining 32 cases without associated anomalies. 2 of 16 cases with contralateral renal agenesis were with oligohydramnios and pulmonary hypoplasia. 2 of 4 bilateral MCDK presented with oligohydramnios and pulmonary hypoplasia. 52 of 53 cases were correctly diagnosed by MRI compared with the final diagnoses; 40 of 53 (75.5%) cases were correctly diagnosed by prenatal ultrasound. Both prenatal ultrasound and MRI failed to correctly diagnose one case bilateral MCDK, and MRI correctly changed the ultrasound diagnosis in 12 cases. Foetal MRI can add additional diagnostic information to prenatal US in the assessment of MCDK, even change the prenatal counselling and decisions.
Assuntos
Doenças Fetais/diagnóstico , Rim Displásico Multicístico/diagnóstico , Adulto , Anormalidades Congênitas/diagnóstico , Imagem de Difusão por Ressonância Magnética/métodos , Feminino , Feto , Idade Gestacional , Humanos , Rim/anormalidades , Nefropatias/congênito , Nefropatias/diagnóstico , Imageamento por Ressonância Magnética/métodos , Gravidez , Diagnóstico Pré-Natal/métodos , Estudos Retrospectivos , Ultrassonografia Pré-Natal/métodos , Anormalidades Urogenitais/diagnósticoRESUMO
OBJECTIVE: To evaluate the utility of fetal cardiac magnetic resonance imaging (MRI) to diagnose right aortic arch (RAA) with right ductus arteriosus. METHODS: This retrospective study included six fetuses with right aortic arch and right ductus arteriosus. The six fetal cases were examined using a 1.5-T magnetic resonance unit. The steady-state free precession (SSFP) and single-shot turbo spin echo (SSTSE) sequences were used to evaluate the fetal heart and airway. The gestational age of the six fetuses ranged from 22 to 35 weeks (mean, 26.5 weeks). The age of the pregnant women ranged from 23 to 40 years (mean 31 years). RESULTS: Fetal cardiac MRI diagnosed the six fetal cases with RAA with right ductus arteriosus correctly. Among the six fetuses, four were associated with other congenital heart defects. In three of six cases, the diagnoses established using prenatal echocardiography (echo) was correct when compared with postnatal diagnosis. CONCLUSIONS: Fetal cardiac MRI is a useful complementary tool to assess fetuses with RAA and right ductus arteriosus.