Sloth E, Houlind K C, Pedersen E M, Hasenkam J M
Department of Anaesthesia, Skejby Sygehus, Aarhus University Hospital, Denmark.
Cardiovasc Res. 1997 Jan;33(1):156-63. doi: 10.1016/s0008-6363(96)00175-7.
To give recommendations for the placement of Doppler sample volumes for blood flow assessment in the human main pulmonary artery.
In 10 healthy volunteers MR-phase velocity measurements were obtained and computing of the mean temporal blood velocity data was performed to guide single point Doppler velocity recordings.
The mean temporal blood velocity profiles were consistently skewed with the lowest blood velocities towards the inferior/right vessel wall. Blood velocity indices (ratio of point to mean velocities, where a point equals a square of 4 pixels) varied considerably with the lowest indices located towards the inferior/right vessel wall. A centrally located fictive sample volume revealed an average blood velocity index value (average of all 10 subjects) of 1.08 (range 0.99-1.25; s.d. 0.08) where the central point was defined at maximum systole, and a value of 1.13 (range 0.97-1.34; s.d. 0.11) when the central point was defined in end-diastole. The mean of multiple sample volumes along the inferior/right to superior/left diameter revealed a blood velocity index of 1.01 (range 0.87-1.21; s.d. 0.09) in systole and 1.03 (range 0.87-1.19; s.d. 0.09) in diastole.
For practical clinical purposes, single point estimation of the mean blood velocity in the pulmonary artery should be performed centrally. The use of multiple sample volumes placed along the inferior/right to superior/left diameter improves the mean velocity estimate in healthy volunteers. Further studies should be conducted to reinforce the basis for Doppler velocity recording in the diseased human pulmonary artery as well as to investigate other important determinants of Doppler-derived CO, namely angle of insonation and assessment of the cross-sectional area.
为人体主肺动脉血流评估中多普勒取样容积的放置提供建议。
对10名健康志愿者进行磁共振相位速度测量，并计算平均瞬时血流速度数据以指导单点多普勒速度记录。
平均瞬时血流速度剖面始终呈偏态，最低血流速度朝向下方/右血管壁。血流速度指数（点速度与平均速度之比，其中一个点等于4像素的平方）变化很大，最低指数位于下方/右血管壁。位于中心的虚拟取样容积在最大收缩期定义中心点时，平均血流速度指数值（所有10名受试者的平均值）为1.08（范围0.99 - 1.25；标准差0.08），在舒张末期定义中心点时为1.13（范围0.97 - 1.34；标准差0.11）。沿下方/右至上方/左直径的多个取样容积的平均值在收缩期显示血流速度指数为1.01（范围0.87 - 1.21；标准差0.09），在舒张期为1.03（范围0.87 - 1.19；标准差0.09）。
出于实际临床目的，肺动脉平均血流速度的单点估计应在中心进行。沿下方/右至上方/左直径放置多个取样容积可改善健康志愿者的平均速度估计。应进行进一步研究，以加强患病人体肺动脉多普勒速度记录的基础，并研究多普勒衍生CO的其他重要决定因素，即声束入射角和横截面积评估。
