Carleton University, Ottawa, Ontario, Canada.
Magn Reson Med. 2010 Mar;63(3):772-81. doi: 10.1002/mrm.22253.
For dynamic contrast-enhanced MRI studies in the human brain, it is useful to measure the venous output function (VOF). The purpose of this work was to explore the feasibility of measuring the VOF using the MR signal phase (in absolute units of gadolinium concentration) in the superior sagittal sinus. Phantom experiments were performed to validate the technique for different superior sagittal sinus angles (theta = 0-48 degrees relative to the main magnetic field), different curvatures (straight or radius = 45 mm), and different spatial resolutions (2.2-5.5 mm, to study partial-volume effects). Additionally, the technique was tested on three patients. The phantom experimental results (echo time = 5.5 ms, theta <or= 21 degrees) agreed with theoretical predictions to within 10%. For the patient studies, the measured VOFs had reasonable amplitude and shape characteristics and the patients' superior sagittal sinus angles (<15 degrees) and curvatures (radii approximately 40 mm) were within the range explored with phantoms. Our results suggest that partial-volume contributions to the VOF will be <5% and that the VOF can be evaluated in vivo to within 10% error. In conclusion, it is highly feasible to use MR signal phase to measure the VOF in the superior sagittal sinus for human dynamic contrast-enhanced MRI.
对于人体脑部的动态对比增强磁共振成像（DCE-MRI）研究，测量静脉输出功能（venous output function，VOF）是非常有用的。本研究旨在探索利用上矢状窦内的磁共振信号相位（以钆浓度的绝对值为单位）来测量 VOF 的可行性。通过对不同上矢状窦角度（相对于主磁场的角度θ=0-48°）、不同曲率（直的或半径=45mm）和不同空间分辨率（2.2-5.5mm，以研究部分容积效应）的模型进行了一系列的仿体实验，验证了该技术。此外，还在 3 名患者中测试了该技术。仿体实验结果（回波时间=5.5ms，θ≤21°）与理论预测值的误差在 10%以内。对于患者研究，测量的 VOF 具有合理的幅度和形状特征，患者的上矢状窦角度（<15°）和曲率（半径约 40mm）均在仿体研究的范围内。我们的结果表明，部分容积对上矢状窦 VOF 的贡献将<5%，并且可以在体内以 10%的误差评估 VOF。总之，利用磁共振信号相位测量人体动态对比增强 MRI 中上矢状窦的 VOF 是非常可行的。
