Hirabuki N, Watanabe Y, Mano T, Fujita N, Tanaka H, Ueguchi T, Nakamura H
Department of Radiology, Osaka University Medical School, Japan.
AJNR Am J Neuroradiol. 2000 Sep;21(8):1497-501.
Cine phase-contrast (PC) MR imaging is a convenient and effective method for measuring volumetric flow rates in vivo. We attempted to evaluate changes in blood flow in the superior sagittal sinus (SSS) in children and to assess the hypothesis that restricted venous outflow attributable to stenosis of the jugular vein causes hydrocephalus in achondroplasia.
Blood flow in the SSS was measured by using cine PC MR imaging with a 1.5-T scanner. After validation, 35 neurologically healthy children as well as eight children with achondroplasia (five with hydrocephalus) and two children with obstructive hydrocephalus were studied. Average flow velocity over the cardiac cycle and volumetric flow rate in the SSS were obtained. The data for healthy children were plotted as a function of age, and reference values were defined by using a five-point smoothing.
In healthy children, flow velocity ranged from 92 to 196 mm/s (mean, 136), and flow rate from 189 to 688 mL/min (mean, 484). The flow rate showed changes statistically related to age. It rapidly increased during the first 2 years and reached a peak by 6 to 8 years of age. The flow velocity showed a similar pattern, but not with significant correlation. In all cases of achondroplasia with hydrocephalus, both flow values were reduced below the reference values minus one standard deviation. In cases of achondroplasia without hydrocephalus, and in obstructive hydrocephalus, the values were not reduced.
Blood flow in the SSS reflects brain maturation. Hydrocephalus associated with achondroplasia was found to be closely related to reduced flow in the SSS, which supports the hypothesis that restricted venous outflow causes hydrocephalus in cases of achondroplasia.
电影相位对比（PC）磁共振成像（MRI）是一种在体内测量容积流速的便捷有效方法。我们试图评估儿童上矢状窦（SSS）血流的变化，并评估颈静脉狭窄导致的静脉流出受限引起软骨发育不全性脑积水这一假说。
使用1.5-T扫描仪通过电影PC MRI测量SSS的血流。验证后，对35名神经功能正常的儿童、8名软骨发育不全儿童（5名患有脑积水）和2名梗阻性脑积水儿童进行了研究。获得心动周期的平均流速和SSS的容积流速。将健康儿童的数据绘制成年龄的函数，并使用五点平滑法定义参考值。
在健康儿童中，流速范围为92至196毫米/秒（平均136），流量范围为189至688毫升/分钟（平均484）。流量显示出与年龄有统计学相关性的变化。在出生后的头2年迅速增加，并在6至8岁时达到峰值。流速显示出类似的模式，但相关性不显著。在所有患有脑积水的软骨发育不全病例中，两个血流值均降低至参考值减一个标准差以下。在没有脑积水的软骨发育不全病例和梗阻性脑积水病例中，这些值没有降低。
SSS中的血流反映了大脑成熟度。发现软骨发育不全相关的脑积水与SSS血流减少密切相关，这支持了静脉流出受限导致软骨发育不全病例中脑积水的假说。
