Cauley Keith A, Filippi Christopher G
Department of Radiology, University of Massachusetts Medical School, Worcester, MA, USA,
Pediatr Radiol. 2014 Jun;44(6):738-46. doi: 10.1007/s00247-013-2864-1. Epub 2014 Mar 21.
Diffusion-weighted imaging is a valuable tool in the assessment of the neonatal brain, and changes in diffusion are seen in normal development as well as in pathological states such as hypoxic-ischemic encephalopathy (HIE). Various methods of quantitative assessment of diffusion values have been reported. Global ischemic injury occurring during the time of rapid developmental changes in brain myelination can complicate the imaging diagnosis of neonatal HIE.
To compare a quantitative method of histographic analysis of brain apparent coefficient (ADC) maps to the qualitative interpretation of routine brain MR imaging studies. We correlate changes in diffusion values with gestational age in radiographically normal neonates, and we investigate the sensitivity of the method as a quantitative measure of hypoxic-ischemic encephalopathy.
We reviewed all brain MRI studies from the neonatal intensive care unit (NICU) at our university medical center over a 4-year period to identify cases that were radiographically normal (23 cases) and those with diffuse, global hypoxic-ischemic encephalopathy (12 cases). We histographically displayed ADC values of a single brain slice at the level of the basal ganglia and correlated peak (s-sDav) and lowest histogram values (s-sDlowest) with gestational age.
Normative s-sDav values correlated significantly with gestational age and declined linearly through the neonatal period (r (2) = 0.477, P < 0.01). Six of 12 cases of known HIE demonstrated significantly lower s-sDav and s-sDlowest ADC values than were reflected in the normative distribution; several cases of HIE fell within a 95% confidence interval for normative studies, and one case demonstrated higher-than-normal s-sDav.
Single-slice histographic display of ADC values is a rapid and clinically feasible method of quantitative analysis of diffusion. In this study normative values derived from consecutive neonates without radiographic evidence of ischemic injury are correlated with gestational age, declining linearly throughout the perinatal period. This method does identify cases of HIE, though the overall sensitivity of the method is low.
扩散加权成像在新生儿脑评估中是一种有价值的工具，在正常发育以及诸如缺氧缺血性脑病（HIE）等病理状态下均可观察到扩散变化。已有多种扩散值定量评估方法的报道。在脑髓鞘快速发育变化时期发生的全脑缺血性损伤会使新生儿HIE的影像诊断复杂化。
比较一种对脑表观扩散系数（ADC）图进行组织学分析的定量方法与常规脑磁共振成像研究的定性解读。我们将正常新生儿影像学检查中扩散值的变化与胎龄相关联，并研究该方法作为缺氧缺血性脑病定量测量指标的敏感性。
我们回顾了本校医学中心新生儿重症监护病房（NICU）4年期间所有的脑MRI研究，以确定影像学检查正常的病例（23例）和弥漫性、全脑缺氧缺血性脑病病例（12例）。我们以组织学方式显示基底节水平单个脑切片的ADC值，并将峰值（s-sDav）和最低组织学值（s-sDlowest）与胎龄相关联。
正常的s-sDav值与胎龄显著相关，并且在新生儿期呈线性下降（r (2) = 0.477，P < 0.01）。12例已知HIE病例中有6例的s-sDav和s-sDlowest ADC值明显低于正常分布所反映的值；部分HIE病例落在正常研究的95%置信区间内，1例病例的s-sDav高于正常。
ADC值的单切片组织学显示是一种快速且临床可行的扩散定量分析方法。在本研究中，来自无缺血性损伤影像学证据的连续新生儿的正常数值与胎龄相关联，在围产期呈线性下降。该方法确实能识别HIE病例，尽管其总体敏感性较低。
