相位对比磁共振成像观察颅内基底动脉、上矢状窦和中脑导水管的生理流动模式

目的 相位对比磁共振成像(PC MRI)观察颅内基底动脉(BA)、上矢状窦(SSS)和中脑导水管(AM)的生理流动模式。方法 选取健康志愿者37名,采用PC MRI测量BA、SSS和AM流体的流动模式。观察时相-流速曲线特征,记录舒张期和收缩期的峰值流速及达峰时相点,并计算两峰值时相差率,记录心动周期内每搏流量、净流量。结果 BA呈单向高幅流动,时相-流速曲线为"缓降-速升-缓降"型;SSS呈单向低幅流动,曲线为"缓降-缓升-缓降"型,两波峰时相差率最小;AM脑脊液呈双向振动式流动,呈"缓升-缓降-缓升型",时相差率最大,绝对每搏流量(74.03±33.22)×10^-3 ml,向4脑室净流量为(3.70±2.78)×10^-3 ml。BA心动周期内两流速波峰间时相差率小于SSS、AM(F=26.63,P<0.01)。结论 BA、SSS及AM的生理流动模式不同。脑室系统、脑组织容积在心动周期内发生动态变化。PC MRI时相-流速曲线可直观、准确地观察脑血管、脑脊液的流动模式。

Phase-contrast MRI observing the physiological flow modes of basilar artery, superior sagittal sinus and aqueduct of midbrain

Objective To explore the physiological flow modes of basilar artery (BA), superior sagittal sinus (SSS) and aqueduct of midbrain (AM) with phase-contrast magnetic resonance imaging (PC MRI). Methods Thirty-seven healthy volunteers were selected and the flow pattern of BA, SSS and AM were measured by 2D PC MRI. The features of phase-velocity curve were observed, the diastolic and systolic peak velocity and time phase point were recorded. Then time phase point rate were calculated. The stroke volume and net flow in cardiac cycle was recorded. Results The flow mode of BA was one-way with high amplitude and the mode of phase-flow velocity curve appeared as "slow descending-fast rising-slow descending"; the flow mode of SSS appeared as one-way with low amplitude and the type of phase-flow velocity curve appeared as "slow descending-slow rising-slow descending"; the flow mode of AM appeayed as "slow rising-slow descendong-slow rising"; time phase point rate was greatest, and its absolute stroke volume was (74.03±33.22)×10^-3 ml, and net flows to the fourth ventricle was (3.70±2.78)×10^-3 ml. The time phase point rate of BA were obviously less than SSS and AM (F=26.63, P<0.01). Conclusion Physiological flow patterns of BA, SSS and AM were different. The ventricular system and brain tissue were changed dynamically in a cardiac cycle indicates volumes. The phase-flow velocity curves of PC MRI can observe the physiological flow modes of cerebral vessels and cerebrospinal fluid intuitively and accurately.