Análise da reprodutibilidade do Doppler de amplitude tridimensional na avaliação da circulação do cérebro fetal

Abstract

OBJETIVO: Avaliar a reprodutibilidade intra e interobservador do Doppler de amplitude tridimensional (3D power Doppler) na avaliação do fluxo sanguíneo cerebral do território da artéria cerebral média. MATERIAIS E MÉTODOS: Foi realizado estudo transversal com 20 gestantes normais entre 26 e 34 semanas. O território da artéria cerebral média mais próximo ao transdutor foi selecionado e o volume foi calculado utilizando-se o método Virtual Organ Computer-aided AnaLysis. Posteriormente, obtiveram-se os índices do 3D power Doppler: índice de vascularização (VI), índice de fluxo (FI) e índice de vascularização-fluxo (VFI). Utilizaram-se, para os cálculos, o coeficiente de correlação intraclasse (CCI) e gráficos de Bland-Altman. RESULTADOS: Foi observada boa concordância intra e interobservador, com CCI > 0,90 para todos os índices do 3D power Doppler: VI [CCI = 0,992 (IC 95%: 0,981-0,997)], FI [CCI = 0,999 (IC 95%: 0,998-0,999)], VFI [CCI = 0,995 (IC 95%: 0,987-0,998)]. Reprodutibilidade interobservador: VI [CCI = 0,988 (IC 95%: 0,970-0,995)], FI [CCI = 0,999 (IC 95%: 0,997-1,000)], VFI [CCI = 0,994 (IC 95%: 0,994-0,998)]. CONCLUSÃO: O 3D power Doppler mostrou-se um método prático, fácil e com boa reprodutibilidade intra e interobservador, com o IF evidenciando a melhor concordância intra e interobservador

Is there any influence of breastfeeding on the cerebral blood flow? A review of 256 healthy newborns

“…The results of this original study with noninvasive cranial Doppler ultrasonography, including 256 healthy neonates to establish the influence of breastfeeding on the cerebral blood flow velocities, showed the occurrence, during breastfeeding, of an increase in MV and a decrease in the resis- tive index and pulsatility index as compared with values at rest, probably due to the increase in the cardiac output caused by the sucking effort, in agreement with other related studies (8,(26)(27)(28) .…”

“…The majority of studies involving Doppler ultrasonography in newborns and relating feeding and arterial blood flow velocities are concerned with the splanchnic haemodynamics adaptation to meal composition in normal full-term newborns (8,(22)(23)(24)(25) , the adaptation to the first feed (26)(27)(28) and the effect of enteral feeding on preterm newborns (29) .…”

“…(neural activity) or to metabolic demands, e.g., the relationship between the increase in of O 2 levels and the cerebral demands (3,8,(11)(12)(13)(14) .…”

“…At the first 2-34 hours of life, the ventricular outputs values significantly exceed those in older children and adults, and the cardiovascular system regulates the cerebral blood flow through variation in cardiac output (4) . As the cerebral blood flow is evaluated, the resistive index remains increased at least until the first 12 hours (5) , then progressively decreases with the gestational age and at each postnatal day (6)(7)(8) . The cerebral blood flow supplies the brain's metabolic demand for O 2 and glucose (9,10) .…”

Malformações do sistema nervoso central e malformações associadas diagnosticadas pela ultrassonografia obstétrica

“…It is known that factors such as quality of apparatuses, sound waves interaction with tissues, examination techniques -appropriate adjustment of gain waveforms, for example -, dedicated scan time, experience and knowledge of the medical sonographer, besides factors such as high maternal body mass índex, fetal statics, advanced gestational age and decreased amniotic fluid index, may change the method sensitivity. Constant perfecting and deep knowledge of specialized methods such as Doppler (29,30) and volumetric (3D/4D) ultrasonography, in association with the increasing technological development with state-of-the-art equipment, have contributed to a good sensitivity of the method in the screening for malformations, with prognostic repercussions.…”