Chang F M, Hsu K F, Ko H C, Yao B L, Chang C H, Yu C H, Liang R I, Chen H Y
Department of Obstetrics and Gynecology, National Cheng Kung University Medical College and Hospital, Tainan, Taiwan.
Ultrasound Obstet Gynecol. 1997 Jan;9(1):42-8. doi: 10.1046/j.1469-0705.1997.09010042.x.
Heart volume may provide important information on the status of fetal hemodynamics. However, traditionally fetal heart volume has been assessed with the erroneous assumption that the fetal heart is spherical or elliptical. With the advent of three-dimensional ultrasound, accurate assessment of organ volume has become feasible. The objectives of this study were to compare the reproducibility of two-dimensional ultrasound and three-dimensional ultrasound in the assessment of heart volume, and to test whether heart volume assessed by the traditional method of two-dimensional ultrasound equates to that assessed by three-dimensional ultrasound. If it proved to be significantly different, we aimed to find a new constant which, if incorporated into the traditional formula used to determine heart volume, would enable us to achieve more accurate volumes with two-dimensional ultrasound. In total, 50 normal singleton fetuses ranging from 20 to 30 weeks' gestation were included in the study. Both the traditional two-dimensional and the new three-dimensional volume measurements were compared. The results showed that three-dimensional ultrasound has a better reproducibility than two-dimensional ultrasound in heart volume assessment and that heart volume assessed by the traditional formula of two-dimensional ultrasound is significantly larger than that measured by three-dimensional ultrasound (p < 0.001). We therefore propose that, if the traditional two-dimensional equation is to be used, the constant for heart volume could be modified to 0.4563 (SE = 0.0153, n = 50) to achieve more accurate results. With this new constant, the heart volume derived by two-dimensional ultrasound was not found to differ from that measured by three-dimensional ultrasound. From our series, we conclude that three-dimensional ultrasound is theoretically the best method for the assessment of heart volume. However, because of the limitations of three-dimensional ultrasound (i.e. it is not routinely available, it is more expensive and more time-consuming) two-dimensional ultrasound in practical terms should be the method of choice. Although we were able to improve the accuracy of the heart volume measurements using a new constant in the traditional two-dimensional formula, the new constant will not improve variability, which can only be reduced by three-dimensional ultrasound.
心脏容积可能为胎儿血流动力学状态提供重要信息。然而，传统上评估胎儿心脏容积时存在一个错误假设，即胎儿心脏是球形或椭圆形的。随着三维超声的出现，准确评估器官容积已变得可行。本研究的目的是比较二维超声和三维超声在评估心脏容积方面的可重复性，并测试通过传统二维超声方法评估的心脏容积是否等同于三维超声评估的结果。如果证明存在显著差异，我们旨在找到一个新的常数，将其纳入用于确定心脏容积的传统公式中，以使我们能够通过二维超声获得更准确的容积。该研究共纳入了50例妊娠20至30周的正常单胎胎儿。对传统二维和新的三维容积测量结果进行了比较。结果表明，在心脏容积评估中，三维超声比二维超声具有更好的可重复性，并且通过二维超声传统公式评估的心脏容积明显大于三维超声测量的结果（p < 0.001）。因此，我们建议，如果要使用传统二维方程，心脏容积常数可修改为0.4563（标准误 = 0.0153，n = 50）以获得更准确的结果。使用这个新常数后，二维超声得出的心脏容积与三维超声测量的结果没有差异。从我们的系列研究中，我们得出结论，理论上三维超声是评估心脏容积的最佳方法。然而，由于三维超声的局限性（即并非常规可用、成本更高且更耗时），实际上二维超声应是首选方法。尽管我们能够通过在传统二维公式中使用新常数来提高心脏容积测量的准确性，但新常数不会改善变异性，变异性只能通过三维超声来降低。
