Department of Radiology, West China Hospital of Sichuan University.
Magn Reson Med Sci. 2018 Apr 10;17(2):145-150. doi: 10.2463/mrms.mp.2016-0139. Epub 2017 Jun 16.
To assess the feasibility of using oxygen and glucose as stimulating agents in blood-oxygen-level-dependent (BOLD) Functional Magnetic Resonance Imaging (fMRI) of rabbit liver and analyze the impacts by blood flow.
Pure oxygen inhalation, intravenous injection and oral administration of glucose were given to 11 New Zealand white rabbits to compare the differences of liver T*, aortic flow (AF), portal vein flow (PVF), aortic area (AA) and portal vein area (PVA) before and at 5 min, 10 min, 20 min, 30 min after administrations. AF and PVF were acquired by two dimensional (2D) Phase Contrast MR (2D-PCMR). The impacts of AF and PVF upon BOLD fMRI were analyzed.
AF and PVF declined at 5 min after oxygen inhalation and were significantly different from baseline, then reverted to baseline. No significant difference was observed in liver T*, AA and PVA before and after oxygen inhalation. AF, PVF, AA and PVA showed no significant difference before and after glucose intravenous injection, while liver T* increased gradually with significant difference. AF and liver T* were significantly different before and after glucose oral administration and increased gradually, AA was significantly different before and after glucose administration at 10 min and 20 min. PVF and PVA started to be different from baseline at 10 min. Greatest variation of T* (19.6%) was induced by glucose oral administration after 30 min.
Rabbit liver T* increasing by glucose intravenous injection is possibly associated with glycogen synthesis, provides the possibility to evaluate liver function. Glucose oral administration demonstrated an optimal comparative effect of raising T*, however, resulted from the superposition of increased glycogen synthesis and blood flow. Inhalation of pure oxygen didn't alter the rabbit liver T*, which may possibly result from an offset between the increased concentration of oxyhemoglobin and decreased blood flow.
评估在兔肝血氧水平依赖（BOLD）功能磁共振成像（fMRI）中使用氧和葡萄糖作为刺激剂的可行性，并分析血流对其的影响。
通过给 11 只新西兰白兔吸入纯氧、静脉注射和口服葡萄糖，比较给药前和给药后 5min、10min、20min、30min 时的肝 T*、主动脉流量（AF）、门静脉流量（PVF）、主动脉面积（AA）和门静脉面积（PVA）的差异。AF 和 PVF 通过二维相位对比磁共振（2D-PCMR）获取。分析 AF 和 PVF 对 BOLD fMRI 的影响。
兔吸入纯氧后 5min 时 AF 和 PVF 下降，与基线相比差异有统计学意义，然后恢复至基线。兔吸入纯氧前后肝 T*、AA 和 PVA 无显著差异。兔静脉注射葡萄糖前后 AF、PVF、AA 和 PVA 无显著差异，而肝 T逐渐增加，差异有统计学意义。兔口服葡萄糖前后 AF 和肝 T差异有统计学意义，且逐渐增加，AA 于给药后 10min 和 20min 与给药前相比差异有统计学意义。PVF 和 PVA 于 10min 时开始与基线不同。口服葡萄糖 30min 后 T*的变化最大（19.6%）。
静脉注射葡萄糖引起兔肝 T增加可能与肝糖原合成有关，为评估肝功能提供了可能。口服葡萄糖可使 T升高的对比效果最佳，但可能是由于肝糖原合成增加和血流增加的叠加作用。兔吸入纯氧不会改变其肝 T*，这可能是由于氧合血红蛋白浓度增加和血流减少之间的相互抵消作用。
