Utsunomiya T, Ogawa T, Doshi R, Patel D, Quan M, Henry W L, Gardin J M
Department of Medicine, University of California, Irvine.
J Am Coll Cardiol. 1991 Apr;17(5):1103-11. doi: 10.1016/0735-1097(91)90839-2.
Previously described Doppler color flow mapping methods for estimating the severity of valvular regurgitation have focused on the distal jet. In this study, a newer Doppler color flow technique, focusing on the flow proximal to an orifice, was used. This method identifies a proximal isovelocity surface area (PISA) by displaying an aliasing interface. Volume flow rate (cm3/s) can be calculated as PISA (cm2) x aliasing velocity (cm/s). For planar circular orifices, a hemi-elliptic model accurately approximated the shape of PISA. Clinically, however, orifice shapes may be noncircular. In vitro flow experiments (n = 226) using orifices of various shapes (ellipse, square, triangle, star, rectangle) were performed. Volume flow rate calculated using a hemi-elliptic model for PISA was accurate, with average percent differences from actual flow rate = +4.3% for a square, -4.2% for a triangle, -4.7% for a star, -4.5% for an ellipse and -2.8% for a rectangle. However, average percent differences for calculated volume flow rates using a hemispheric model for PISA shape ranged from -11.6% (square) to -34.8% (rectangle). In addition, to evaluate whether PISA is influenced by machine factors, in vitro studies (n = 83) were performed.(ABSTRACT TRUNCATED AT 250 WORDS)
先前描述的用于评估瓣膜反流严重程度的多普勒彩色血流图方法主要关注远端血流束。在本研究中，使用了一种更新的多普勒彩色血流技术，该技术聚焦于孔口近端的血流。此方法通过显示混叠界面来识别近端等速表面积（PISA）。体积流量（cm³/s）可通过PISA（cm²）乘以混叠速度（cm/s）来计算。对于平面圆形孔口，半椭圆模型能准确地近似PISA的形状。然而在临床上，孔口形状可能是非圆形的。进行了体外血流实验（n = 226），使用了各种形状（椭圆形、方形、三角形、星形、矩形）的孔口。使用半椭圆模型计算PISA得出的体积流量是准确的，对于方形，与实际流量的平均百分比差异为 +4.3%，三角形为 -4.2%，星形为 -4.7%，椭圆形为 -4.5%，矩形为 -2.8%。然而，使用半球形模型计算PISA形状的体积流量时，平均百分比差异范围从 -11.6%（方形）到 -34.8%（矩形）。此外，为了评估PISA是否受机器因素影响，进行了体外研究（n = 83）。（摘要截短于250字）
