ABSTRACT
Abstract Ultrasound diagnosis of posterior fossa malformations in the prenatal period is a challenge, having major implications for the counseling and follow-up of pregnant women. The purpose of this study was to review aspects of the ultrasound evaluation of the fetal posterior fossa, as well as to describe the most relevant ultrasound findings of the main posterior fossa malformations that can affect the fetus in the prenatal period.
Resumo O diagnóstico ultrassonográfico das malformações da fossa posterior no período pré-natal é um desafio, com importantes implicações no aconselhamento e acompanhamento dessas gestações. O objetivo deste estudo é revisar aspectos da avaliação ultrassonográfica da fossa posterior do feto e descrever os principais achados ultrassonográficos das principais malformações da fossa posterior que podem acometer o feto no período pré-natal.
ABSTRACT
OBJETIVO: Avaliar, por meio da ressonância magnética, uma série de fetos com diagnóstico ultra-sonográfico de malformação, a fim de estabelecer os benefícios e limites diagnósticos proporcionados pela técnica de ressonância magnética fetal, em comparação com a ultra-sonografia. MATERIAIS E MÉTODOS: Foram estudadas 40 mulheres entre 15-35 semanas de gestação com diagnóstico de anomalia fetal durante o exame de ultra-sonografia. As pacientes foram encaminhadas para o estudo complementar com ressonância magnética. As indicações para o estudo da ressonância magnética fetal foram: anomalias do sistema nervoso central, do tórax, do abdome, renais, esqueléticas e tumores. A avaliação pós-natal incluiu a revisão das imagens de ultra-sonografia e ressonância magnética, o acompanhamento do nascimento, exames laboratoriais, radiológicos e necropsia. RESULTADOS: Os resultados mostraram que os estudos complementares com ressonância magnética fetal trouxeram informações adicionais em 60 por cento dos casos estudados. Os benefícios da ressonância magnética fetal foram: ampliação da avaliação global, aumento do campo de avaliação, maior resolução tecidual pelo uso de seqüências, e avaliação em pacientes obesas e com oligoidrâmnio. Os limites da ressonância magnética fetal foram: evitar exame no primeiro trimestre, avaliação do fluxo sanguíneo, movimentação fetal, claustrofobia materna, estudo do coração fetal e esqueleto. CONCLUSÃO: A ressonância magnética fetal pode ser utilizada como método complementar para a avaliação das malformações fetais.
OBJECTIVE: The present study was aimed at evaluating by means of magnetic resonance imaging a series of fetuses with sonographic diagnosis of malformation, establishing the diagnostic benefits and limitations of fetal magnetic resonance imaging as compared with ultrasonography. MATERIALS AND METHODS: Forty women between 15-35 gestational weeks and previously diagnosed with fetal abnormality by ultrasonography were referred to undergo complementary fetal magnetic resonance imaging, particularly for evaluating abnormalities in the fetal central nervous system, thorax, abdomen, renal system, skeletal system, and tumors. The whole evaluation process included a review of the fetal ultrasonography and magnetic resonance images, postnatal follow-up, laboratory tests, imaging studies and necropsy. RESULTS: The present study has demonstrated that complementary magnetic resonance imaging did provide further information in 60 percent of cases, with the following benefits: improved information on the fetus as a whole, with a large field of view, higher anatomic resolution provided by fast sequences, superior soft tissue contrast resolution, besides the fact that the visualization of the fetus is not significantly affected by maternal obesity or oligohydramnios. Limitations of the method include contraindication in the first gestational trimester and in cases of maternal claustrophobia, sensitivity to fetal motion, low sensitivity for detecting cardiovascular and skeletal malformations. CONCLUSION: Fetal magnetic resonance imaging plays a significant role as a complementary method for the diagnosis of fetal anomalies.
Subject(s)
Humans , Female , Pregnancy , Congenital Abnormalities , Fetal Diseases , Fetal Development , Fetus/abnormalities , Magnetic Resonance Imaging , Prenatal Diagnosis , Diagnostic Imaging , Fetus/anatomy & histologyABSTRACT
CONTEXT: The literature shows an association between several ultrasound markers and chromosome abnormality. Among these, measurement of nuchal translucency has been indicated as a screening method for aneuploidy. The trisomy of chromosome 21 has been most evaluated. OBJECTIVE: To define the best fixed cutoff point for nuchal translucency, with the assistance of the ROC curve, and its accuracy in screening all fetal aneuploidy and trisomy 21 in a South American population. TYPE OF STUDY: Validation of a diagnostic test. SETTING: This study was carried out at the State University of Campinas, Campinas, Brazil. PARTICIPANTS: 230 patients examined by ultrasound at two tertiary-level private centers, at 10 to 14 weeks of gestation. DIAGNOSTIC TEST: The participants consisted of all those patients who had undergone ultrasound imaging at 10 to 14 weeks of gestation to measure nuchal translucency and who had had the fetal or neonatal karyotype identified. MAIN MEASUREMENTS: Maternal age, gestational age, nuchal translucency measurement, fetal or neonatal karyotype. RESULTS: Prevalence of chromosomal defects -- 10 percent; mean age -- 35.8 years; mean gestational age -- 12 weeks and 2 days; nuchal translucency (NT) thickness -- 2.18 mm. The best balance between sensitivity and specificity were values that were equal to or higher than 2.5 mm for overall chromosomal abnormalities as well as for the isolated trisomy 21. The sensitivity for overall chromosomal abnormalities and trisomy 21 were 69.5 percent and 75 percent, respectively, and the positive likelihood ratios were 5.5 and 5.0, respectively. CONCLUSION: The measurement of nuchal translucency was found to be fairly accurate as an ultrasound marker for fetal abnormalities and measurements equal to or higher than 2.5 mm were the best fixed cutoff points
Subject(s)
Humans , Female , Pregnancy , Adult , Middle Aged , Trisomy , Chromosomes, Human, Pair 21 , Ultrasonography, Prenatal , Chromosome Aberrations , Pregnancy Trimester, First , Brazil/epidemiology , Prevalence , Chromosome Aberrations/epidemiology , Sensitivity and Specificity , Age Factors , Maternal Age , False Positive Reactions , Karyotyping , Aneuploidy , Down SyndromeABSTRACT
Faz-se breve comentário sobre a rotina da utilizaçäo dodoppler-colorido em medicina fetal. Sâo considerads suas principais indicaçöes e interpretaçäo de seus resultados no acompanhmento da gestaçäo de primeiro trimestre, no diagnóstico da prenhez ectópica, no estudo de cordäo umbilical, no rastreamento e seguimento da neoplasia trofoblástica gesrtacional e na avliaçäo do perfil hemodinâmico fetal. Breves consideraçöes adicionais sobre a fisiopatologia do sofrimento fetal crônico säo desenvolvidas
Subject(s)
Humans , Female , Pregnancy , Umbilical Cord , Fetus/blood supply , Pregnancy, Ectopic , Risk Factors , UltrasonicsABSTRACT
Faz-se breve comentário sobre marcadores nåo-invasivos de alteraçöes cromossomiais do feto. Såo considerados os métodos bioquímicos e os métodos biofísicos para o rastreamento de anomalias citogenéticas, reservadas às pacientes de baixo-risco. Aborda-se também os métodos diagnósticos da doença, por procedimento invasivos, v.g., a biópsia de vilo corial, a amniocentese e a cordoncentese, métodos indicados nas pacientes de alto-risco caracterizada por sua história ou por alteraçöes verificadas nos procedimentos nåo-invasivos