?根據(jù)七月的《放射學(xué)》雜志,，研究人員最近使用了一種新技術(shù)來(lái)觀察嬰兒大腦發(fā)育以及檢測(cè)腦白質(zhì)紊亂。
??挪威Veldhoven 的Máxima 醫(yī)學(xué)中心的Carola van Pul博士和他的同事研究了七個(gè)正常的嬰兒和十個(gè)產(chǎn)期缺氧貧血的嬰兒－一種大腦在一個(gè)階段氧氣以及營(yíng)養(yǎng)缺乏而導(dǎo)致的腦損傷,，經(jīng)常是由于母親向嬰兒傳輸營(yíng)養(yǎng)時(shí)期的復(fù)雜情況造成的。缺氧貧血損傷可以導(dǎo)致嚴(yán)重的動(dòng)力問(wèn)題。
??van Pul 博士說(shuō)：“這種大腦損傷的模式嚴(yán)重的影響到了嬰兒的神經(jīng)和正常的發(fā)育,。早期階段的損傷檢測(cè)對(duì)于嬰兒的發(fā)育是必要的，可以避免大腦的永久性損傷以及提高優(yōu)生率,。”
??研究人員使用“擴(kuò)張量”核磁共振技術(shù),，即描述組織中的水分子的擴(kuò)散或者置換程度。貧血導(dǎo)致組織變化能夠通過(guò)擴(kuò)散量成像得到,，要比傳統(tǒng)的核磁共振早兩到三個(gè)小時(shí),。這個(gè)研究小組應(yīng)用光纖跟蹤技術(shù)，通過(guò)擴(kuò)散量成像構(gòu)建一個(gè)大腦白質(zhì)的三維立體圖,。應(yīng)用這項(xiàng)技術(shù),，經(jīng)過(guò)三個(gè)月?lián)p傷區(qū)域的發(fā)育的監(jiān)測(cè)，重構(gòu)出了大腦白質(zhì)圖,。這在世界上,，是第一次歷時(shí)三個(gè)月通過(guò)光纖追蹤技術(shù)來(lái)評(píng)價(jià)新生兒大腦發(fā)育狀況的技術(shù)。
??一開(kāi)始，光纖追蹤技術(shù)就顯示了10個(gè)貧血嬰兒有8個(gè)嬰兒的大腦圖譜不同于正常嬰兒,。大腦白質(zhì)的光纖成像技圖譜發(fā)現(xiàn)大腦的幾個(gè)區(qū)域紊亂,，包括胼胝體－連接大腦兩半球的神經(jīng)組織構(gòu)成的拱形橋，能使大腦左右兩半交流,，最重要的是輻射冠,，起調(diào)整人體協(xié)同運(yùn)動(dòng)作用。所有的有著輻射冠紊亂模式的嬰兒明顯有著動(dòng)力協(xié)調(diào)問(wèn)題,。
??van Pul 博士說(shuō)：“嬰兒的微小的腦白質(zhì)變態(tài)可以通過(guò)三個(gè)月時(shí)間的光纖跟蹤技術(shù)觀察到,，它們有著明顯持續(xù)的標(biāo)記變化。”
??缺氧性貧血是導(dǎo)致嬰兒致死和病態(tài)一個(gè)重要的原因,。在美國(guó)大約每一千個(gè)新生兒有一到兩個(gè)會(huì)患有此病,。
Researchers have used a new technique to monitor brain development in infants and detect disturbances in white matter, according to a study in the July issue of Radiology.
Carola van Pul, Ph.D., and colleagues from Mḩma Medical Center in Veldhoven, the Netherlands, studied seven normal infants and 10 infants with perinatal hypoxic ischemia, a type of brain injury caused by a period of oxygen and nutrient deficiency, usually as a result of complications during delivery. Hypoxic ischemic injury can result in severe motor problems.
"The pattern and extent of the brain injury largely determine the neurological and developmental consequences for the newborn," Dr. van Pul said. "The detection of injury at an early stage is essential for the development of strategies to limit permanent brain damage and to improve prognosis."
The researchers used 'diffusion tensor' magnetic resonance imaging (MRI), which depicts the diffusion, or displacement, of water molecules through tissue. Ischemia results in tissue changes that are visible with diffusion tensor imaging at least two to three hours before they can be seen on conventional MRI. The team then applied fiber tracking to construct a 3-D visualization of the brain's white matter tracts based on the diffusion tensor images. The procedure was repeated after three months to monitor the development of the injured regions. This is the first time a group of newborns has been evaluated with fiber tracking at birth and at three months.
At birth, fiber tracking showed a different fiber pattern in eight of the 10 neonates with ischemia, compared to the images obtained from the normal infants. The fiber pattern of the brain's white matter was disturbed in several areas of the brain, including the corpus callosum, which allows communication between the two hemispheres of the brain, and, most significantly, the corona radiata, which is associated with finely coordinated movement. Six of the 10 infants continued to exhibit disturbed fiber patterns at follow-up. All of the infants who had disturbed patterns in the corona radiata at three months had major motor problems.
"Minor white matter abnormalities seen with fiber tracking tended to resolve at three months, while marked changes persisted," Dr. van Pul said. "Further investigation is needed to determine whether the detected fiber abnormalities ultimately correlate with outcomes."
Hypoxic ischemia remains an important cause of infant mortality and morbidity, with an incidence of between one and two per 1,000 live births in the United States.
